Anatomy Exam 3 Notecards Upper Limb

Front 1

What are the factors that determine the force that a muscle exerts?

Back 1

size and shape, angle of pull relative to the axis and insertion site, in general the upper extremity is designed for speed, lower for power and all muscles help to stabilize the joint they cross

Front 2

What are the two things that we must know in analyzing muscle action?

Back 2

1. the potential movements allowed at the joint and the axes of those movements
2. how the muscle crosses the joint relative to the axes (does it pass anterior, superior, posterior), a muscle that passes through an axis can’t do any movement in that axis

Front 3

What movements occur at the glenohumeral joint?

Back 3

1. abduction (superior to axis), adduction (inferior to axis) =axis is AP
2. flexion (front to back to axis), extension (back to front to axis)=axis is the transverse axis
3. rotation=axis is vertical axis

Front 4

Describe the scapula.

Back 4

triangular bone that overlies the 2nd-7th rib, posterior surface is divided by the spine of the scapula into a small supraspinous fossa and a larger infraspinous fossa, continues laterally as the acromion which forms the subQ point of the shoulder and articulates with the acromial end of the clavicle

Front 5

What is the subscapular fossa?

Back 5

on the anterior surface of the muscle, is the concave costal curface of most of the scapula

Front 6

Describe the coracoid process.

Back 6

beak like, superior to the glenoid cavity and projects anterolaterally, resembles in size, shape and direction a bent finger pointing to the shoulder, the knuckle of which provides the inferior attachment for the passively supporting coracoclavicular ligament

Front 7

Describe the movements of the scapula.

Back 7

is capable of considerable movement on the thoracic wall at the physiological scapulothoracic joint, providng the base from which the upper limb operates, these movements allow the arm to move freely

Front 8

Where does the scapula articulate?

Back 8

articulates with the clavicle at the acromion and the two bones collectively form the shoulder girdle

Front 9

Describe the superior angle of the scapula.

Back 9

is marked near the junction of its medial two thirds and lateral third by the suprascapular notch which is located where the superior border joins the base of the coracoid process, the superior border is the thinnest and shortest of the three borders

Front 10

Describe the medial border of the scapula.

Back 10

thin, runs parallel to and approximately 5 cm lateral to the spinous processes of the thoracic vertebrae (called the vertebral border)

Front 11

Describe the axillary (lateral) border of the scapula.

Back 11

from the inferior angle, runs superolaterally toward the apex of the axilla, made up of a thick bar of bone that prevents buckling of this stress-bearing region of the scapula, terminates in the lateral angle of the scapula, the thickest part of the bone that bears the broadened head of the scapula

Front 12

Why are the angles important?

Back 12

help define rotational movements

Front 13

What is the importance of the clavicle?

Back 13

only bony attachment of the upper limb to the axial skeleton, at the sternal end, the first long bone to ossify (weeks 5-6) but also last to complete it, is membranous in origin, S-shaped, shock absorber, most common place is to fracture is the medial 1/3 and lateral 2/3, has roughenings for attachments, lateral surface is flatter, superior surface is smoother, inferior has more roughenings, S-shape is convex at medial portion when looking anteriorly at it

Front 14

What are the functions of the clavicle?

Back 14

1. rigid support which the scapula and free limb are suspended keeping them away from the trunk so that the limb has maximum freedom of motion, allows the scapula to move on the thoracic wall at the scapulothoracic joint
2. bony boundary of the cervicoaxillary canal (between neck and arm), affording protection to the neurovascular bundle supplying the upper limb
3. transmits shocks from the upper limb to the axial skeleton

Front 15

Describe the acromioclavicular joint.

Back 15

plane type of synovial joint where the acromion of scapula and lateral end of clavicle are joined, allows some movement, important in protraction and retraction, clavicle moves front and back in the vertical axis at the SC joint, when protracting and retracting the scapula moves with the clavicle and also rotates with the rib cage

Front 16

Describe the joint capsule of the acromioclavicular joint.

Back 16

loose fibrous layer of the joint capsule is attached to the margins of the articular surfaces, synovial membrane lines the fibrous layer, is relatively weak, is strengthened superiorly by the fibers of the trapezius

Front 17

What ligaments are found in the AC joint?

Back 17

1. coracoclavicular ligaments-trapezoid (horizontal, attached to superior surface of the coracoid and extends laterally to the trapezoid line of clavicle) and conoid ligaments (inverted triangle with apex attached to roof of the coracoid process, base is at conoid of clavicle)
2. coracoacromial ligament-forms the roof

Front 18

Describe the coracoclavicular ligaments.

Back 18

pair of bands that unite the coracoid process of the scapula to the clavicle anchoring the clavicle to the coracoid process, the trapezoid and conoid ligaments are separated by a bursa provides the means by which the scapula and free limb (passively) are suspended from the clavicuarl strut, without these ligaments would have more shoulder separations, stabilizes clavicle

Front 19

Describe the coracoacromial ligament.

Back 19

between coracoid process and acromion, forms a shelf that the humerus can bump into

Front 20

Describe the movements of the AC joint.

Back 20

acromion of scapula rotates on the acromial end of clavicle, no muscles connect the articulating bones to move the AC joint, the axioappendicular muscles that attach to and move the scapula cause the acromion to move on the clavicle

Front 21

Describe the blood supply to the AC joint.

Back 21

supplied by the suprascapular and the coracoacromial arteries

Front 22

Describe the nerve supply to the AC joint.

Back 22

supplied by the lateral pectoral and axillary nerves, also provided by the subQ lateral supraclvicular nerves (an occurrence more typical of the distal limb)

Front 23

What is the Hilton law?

Back 23

joints are supplied by articular branches of the nerves supplying the muscles that act on the joint

Front 24

What are A-C separations and ligament tears?

Back 24

shoulder separation occurs at the A-C joint (tearing some of the ligament of the capsule surrounding A-C joint, usually from fall of elbow), whereas dislocation occurs at the glenohumeral joint (pop humerous out of gleno cavity, goes anteriorly and inferiorly)

Front 25

Describe the sternoclavicular joint.

Back 25

where the medial (sternal) half of the clavicle articulates with the manubrium of the sternum, has two joint cavities separated by an articular disk (like TMJ), important for movement, saddle type of synovial joint but functions as a ball-and-socket joint, serves as a shock absorber

Front 26

Describe the joint capsule of the sternoclavicular joint.

Back 26

surrounds the SC joint, including the epiphysis at the sternal end of the clavicle, it is attached to the margins of the articular surfaes, including the periphery of the articular disc, a synovial membrane lines the internal surface of the fibrous layer of the joint capsule, extending to the edges of the articular surfaces

Front 27

Describe the ligaments of the SC joint.

Back 27

1. anterior and posterior sternoclavicular ligaments reinforce the joint capsule anteriorly and posteriorly
2. interclavicular ligament strengthens the capsule superiorly, its extends from the sternal end of one clavicle to the sternal end of the other clavicle, is also attached to the superior border of the manubrium
3. costoclavicular ligament anchors the inferior surface of the sternal end of the clavicle to the 1st rib and its costal cartilage, limiting elevation of the pectoral girdle

Front 28

Describe the movements of the SC joint.

Back 28

allows movements of the pectoral girdle and upper limb, during full elevation of the limb the clavicle is raised to a 60 angle, flexion leads to roation of the clavicle on longitudinal axis, can also perform circumduction

Front 29

What axis are available for the movement in the SC joint.

Back 29

1. vertical axis-protraction/retraction, need AC joint for the scapula to move along the thoracic cage
2. AP axis-elevation/depression, inferior angle stays in same spot except goes up or down, need AC joint to move
3. oblique axis-medial/lateral rotation, inferior angle goes way out in either a lateral or medial direction (important to rotate scapula like this bec. glenoid cavity tips up and is important for full abduction, if don’t tip it up then can only go up a little bit)

Front 30

Describe the oblique axis

Back 30

pass pin through the SC joint and comes out lateral 1/3 of the scapula underneath the spine, AC joint doesn’t move during this rotation, can’t get complete abduction because acromion is hit

Front 31

Describe the blood supply to the SC joint.

Back 31

supplied by the internal thoracic and suprascapular arteries

Front 32

Describe the nerve supply to the SC joint.

Back 32

branches of the medial supraclavicular nerve and the nerve to the subvclavius supply to the SC joint

Front 33

Describe the movements of the arm.

Back 33

only a portion (120) of the 180 of abduction at the shoulder takes place at the glenohumeral joint, 60 occurs at the sternoclavicular joint, this combination of movements (2:1) is called scapulohumeral rhythm

Front 34

Describe the movements of the trapezius and the axis involved.

Back 34

trapezius attaches to the vertebral column, the trapezius can be divided into three parts (upper, middle and lower), each performing different movements, vertical axis (all retract), A-P axis (superior elevates, inferior depresses, middle is not much at all) and olique axis (all three laterally rotate), innervation is by CN XI

Front 35

What muscles of the SC-joint are responsible for protraction?

Back 35

serratus anterior, pectoralis minor

Front 36

What muscles of the SC-joint are responsible for retraction?

Back 36

trapezius (middle), rhomboid major and minor

Front 37

What muscles of the SC-joint are responsible for elevation?

Back 37

trapezius (upper), levator scapulae, rhomboid major and mino

Front 38

What muscles of the SC-joint are responsible for depression?

Back 38

serratus anterior, pectoralis minor, trapezius (lower)

Front 39

What muscles of the SC-joint are responsible for mediatl rotation?

Back 39

pectoralis minor, rhomboid major and minor and levator scapulae

Front 40

What muscles of the SC-joint are responsible for lateral rotation?

Back 40

trapezius (all parts) and serratus anterior

Front 41

What is the nerve supply and movements of the rhomboids?

Back 41

dorsal scapular nerve, retracts scapula and medially rotates scapula

Front 42

What is the nerve supply and movement of the levator scapulae?

Back 42

elevates and medially rotates scapula, supplied by the dorsal scapular nerve

Front 43

What role does the latissimus dorsi have in SC joint movement?

Back 43

doesn’t act on the S-C joint but is the last extrinsic back muscle that is really a muscle of the upper limb, action is at the glenohumeral joint, arises from the thoracolumbar fascia to humerus superolateraly, powerful adductor and extensor of the arm (as in climbing), nerve supply is from the thoracodorsal nerve (middle subscapular)

Front 44

What movements and axis does the latissimus dorsi have in the glenohumeral joint?

Back 44

1. vertical axis-medial rotation
2. transverse axis-inferior to this axis and causes extension
3. AP axis-inferior, is an adductor

Front 45

What role does the pectoralis minor have in movements involving the SC joint?

Back 45

comes from ribs and attaches to corocoid process of scapula, innervated by the medial pectoral nerve, depresses (AP axis), protracts (vertical axis) and medially rotates (oblique axis) the girdle

Front 46

What role does the serratus anterior have in movements involving the SC joint?

Back 46

huge origin from ribs, fans deep to scapula and attaches along medial border and inferior angle of scapula, innervated by the long thoracic nerve, depresses on AP axis, protracts on vertical axis, laterally rotates on oblique axis, is also very important in holding the medial border of the scapula tight against the ribs, damage to the long thoracic (only nerve supply that is not deep to the scapula, results in winging of the scapula

Front 47

What is a winged scapula?

Back 47

occurs when the scapula is not held strongly against the thoracic cavity, medial border pops away from the chest wall, may also pop out if try to abduct completely

Front 48

Where are movements of the scapula transmitted to?

Back 48

the humerus, arm movements occurs at the glenohumeral joint, need to stabilize/fix the glenohumeral joint to get movements of the arm

Front 49

Describe the glenohumoral joint.

Back 49

it is a ball and socket type of synovial joint that permits a wide range of movements, its mobility makes the joint relatively unstable

Front 50

Describe the articulation of the glenohumoral joint.

Back 50

humeral head articulates with the glenoid cavity of the scapula, both articular surfaces are covered by hyaline cartilage, humeral head is held in the cavity by the tonus of the musculotendinous rotator cuff (SITS) muscles (supraspinatus, infraspinatus, teres minor and subscapularis)

Front 51

Describe the joint capsule of the glenohumoral joint.

Back 51

loose fibrous layer is attached medially to the margin of the glenoid cavity and laterally to the anatomical neck of the humerus, superiorly it encroaches on the root of the coracoid process so that the fibrous layer encloses the proximal attachment of the long head of the biceps brachii to the supraglenoid tubercle of sapula within the joint

Front 52

What are the two apertures of the joint capsule?

Back 52

1. an opening between the tubercles of the humerus for passage of the tendon of the long head of the biceps brachii
2. an opening situated anteriorly inferior to the coracoid process that allows communication between the subscapular bursa and the synovial cavity of the joint

Front 53

Where is the weakest area of the glenohumoral joint?

Back 53

the inferior part of the joint capsule, the only part not reinforced by the rotator fucc muscles, here the capsule is particularly lax and lies in folds when the arm is abducted

Front 54

Describe the synovial membrane of the glenohumoral joint.

Back 54

lines the internal surface of the fibrous layer of the joint capsule and reflects from it onto the glenoid labrum and the humerus as far as the articular margin of the head, it also forms a tubular sheath for the tendon of the long head of the biceps brachii where it lies in the intertubercular groove of the humerus and passes into the joint cavity

Front 55

What is the importance of the glenohumeral ligaments?

Back 55

they are three fibrous bands, that reinforce the anterior part of the joint capsule, they radiate laterally and inferiorly from the glenoid labrum at the supraglenoid tubercle of the scapula and blend distally with the fibrous layer of the capsule as it attaches to the anatomical neck of the humerus

Front 56

What is the significance of the coracohumeral ligament?

Back 56

it is a strong borad band that passes from the basse of the coracoid process to the anterior aspect of the greater tubercle of the humerus

Front 57

Describe the transverse humeral ligament.

Back 57

a broad fibrous band that runs more or lexx obliquely from the greater to the lesser tubercle of the humerus, bridging over the intertubercular groove, converts the groobe into a canal, which holds the synovial sheath and tendon of the biceps brachii in place during movements of the glenohumeral joint

Front 58

What is the coracoacromial arhc?

Back 58

it is an extrinsic, protective structure formed by the smooth inferior aspect of the acromion and the coracoid process of the scapula, the coracoacromial ligament spans between them

Front 59

What does the coracoacromial ligament do?

Back 59

it forms a protective arch that overlies the humeral head, preventing its superior displacement from the glenoid cavity

Front 60

Describe the allowable movements of the glenohumeral joint.

Back 60

has more freedom of movement than any other joint in the body, results from the laxity of its joint capsule and the large size of the humeral head compared with the small size of the glenoid cavity, allows for flexsion-extension (horizontal transverse axis), abduction-adduction (horizontal AP axis), medial and lateral rotation (vertical axis), and circumduction

Front 61

What muscles of the glenohumeral joint allow for flexion?

Back 61

pectoralis major (clavicular head), deltoid (anterior part), coracobrachialis

Front 62

What muscles of the glenohumeral joint allow for extension?

Back 62

deltoid (posterior part), teres major

Front 63

What muscles of the glenohumeral joint allow for abduction?

Back 63

deltoid (as a whole, but especially central part), supraspinatus

Front 64

What muscles of the glenohumeral joint allow for adduction?

Back 64

pectoralis major, latissimus dorsi, subscapularis, infraspinatus, teres minor

Front 65

What muscles of the glenohumeral joint allow for medial rotation?

Back 65

subscapularis, pec major, deltoid (anterior part), latissimus dorsi

Front 66

What muscles of the glenohumeral joint allow for lateral rotation?

Back 66

infraspinatus, teres major, deltoid

Front 67

What muscles of the glenohumeral joint are tensors of the articular capsule (to hold head of humerus against glenoid cavity?

Back 67

supscapularis, infraspinatus (simultaneously), supraspinatus, teres minor

Front 68

What muscles of the glenohumeral joint resist downward dislocation (shunt muscles)?

Back 68

deltoid (as a whole), long head of triceps, coracobrachialis, short head of biceps

Front 69

What is the blood supply of the glenohumeral joint?

Back 69

supplied by the anterior and posterior circumflex humeral arteries and branches of the suprascapular artery

Front 70

Describe the innervation of the glenohumeral joint.

Back 70

supplied by the suprascapular, axillary and lateral pectoral nerves

Front 71

What are bursae?

Back 71

sac-like cavities filled with capillary films of synovial fluid, located where tendons rub against bone, ligaments or other tendons, allow for sliding movements

Front 72

Describe the subscapular bursa.

Back 72

located between the tendon of the subscapularis and the neck of the scapula, protects the tendon where it passes inferior to the root of the coracoid process, an extension of the glenohumeral joint cavity

Front 73

Describe the subacromial bursa.

Back 73

locatred between the acromion, coracoacromial ligament and deltoid superiorly and the supraspinatus tendon and joint capsule of the glenohumeral joint inferiorly

Front 74

Describe the importance of the pectoralis major at the glenohumeral joint.

Back 74

innervated by the medial and lateral pectoral, actions at the GH joint include flexion, adduction, medial rotation, passes from clavical and sternal region just in front of the intertubercular groove, in front of the transverse axis in anatomical position

Front 75

Describe the importance of the deltoids at the glenohumeral joint.

Back 75

arises from calvicle to spinus scapula, it does not have an attachment to the axial skeleton so no action at S-C joint, innervated by the axillary nerve,

Front 76

What movements do the deltoid take care of at the GH joint

Back 76

is responsible for every movement at the GH joint, flexion by the anterior part, extension by the posterior part, abduction by the middle part, adduction by the posterior and anterior part, medial rotation by the anterior part and lateral rotation by the posterior part

Front 77

Describe the importance of the latissimus dorsi and teres major at the GH joint.

Back 77

both have an attachment at the intertubercular groove area of the humerus, LD innervated by middle subscapular or thoracodorsal nerve, TM from the lower subscapular nerve, actions at the GH joint are extension, adduction and medial rotation

Front 78

What is the importance of the rotator cuff?

Back 78

they are muscles that stabilize the glenohumeral joint, GH joint is built for mobility, the rotator cuff (SITS) adds stability to the GH join, strengthens anteriorly, superiorly and posteriorly (not inferiorly, this is where dislocation occurs most, occurs when fully extended the arm), the rotatory functions of the muscles help with full range of the joint, external rotation of the humerus during flexion or abduction prevents the greater tubercle from hitting the acromion

Front 79

Where is the attachments points for the differents SITS muscles

Back 79

Subscapularis-lesser tubercle
supraspinatus-underneath the acromion, greater tubercle
infraspinatus-greater tubercle
teres minor-greater tubercle

Front 80

Describe the interaction of the greater tubercle and acromion.

Back 80

greater tubercle when abduct is very close to the acromion, when doing medial rotation, greater tubercle starts to interfere with acromion, when laterally rotate easier to fully abduct

Front 81

What are the rotator cuff muscles?

Back 81

SITS muscles, supraspinatus (abduction, good for initiating abduction), infraspinatus (lateral rotation), teres minor (lateral rotation, could also do adduction) and subscapularis (medial rotation, very good), each has basically one action

Front 82

Describe rotator cuff tears.

Back 82

tearing of the fibrocartilaginous glenoid labrum commonly occurs in atheletes who throw a baseball or football and in those who have shoulder instability and subluxation of the GH joint, often results from sudden contraction of the biceps or forceful subluxation of the humeral head over the glenoid labrum, supraspinatus most likely teared due to impingement syndrome

Front 83

What is the blood and nerve supply of the cuff?

Back 83

supra and infraspinatus-suprascapular nerve and artery
terese minor-axillary nerve and posterior humeral circumflex artery
subscapularis-upper and lower subscapularis + circumflex scapular artery

Front 84

What is the quadrilateral space?

Back 84

four structures make up this space, terese minor and major, humerus and long head, axillary nerve and posterior humeral artery both exit here

Front 85

Describe the collateral flow of the rotator cuff.

Back 85

dorsal scapular, suprascapular artery, posterior circumflex humeral artery, circumflex scapular from subscapular artery, important for collateral flow, can tie off axillary artery between thyrocervical trunk and subscapular artery and repair it and still maintain blood supply to upper limb via this collateral flow

Front 86

How are the muscles of the upper limb tested?

Back 86

test the strength of the muscles synergistically functioning at each axis at the GH joint
1. normal-full ROM against max. resistance
2. good-full ROM against less than max. resistance, or partial range of motion against max. resistance
3. fair-full ROM against the force of gravity
4. poor-partial ROM against force of gravity
5. trace-little or no movement, palpable contraction of agonists

Front 87

What is the proximal, distal, innervation and main action of the pectoralis major?

Back 87

proximal-clavicular head (anterior surface of medial half of clavicle), sternocostal head (anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle)
distal-lateral lip of intertubercular groove of humerus
innervation-lateral and medial pectoral nerves, clavicular head (C5, C6), sternocostal head (C7-T1)
main action-adducts and medially rotates humerus, draws scapula anteriorly and inferiorly, acting alone, clavicular head flexes humerus and sternocostal head extends it from the flexed position

Front 88

What is the proximal, distal, innervation and main action of the pec minor?

Back 88

proximal-3rd-5th ribs near their costal cartilages
distal-medial border and superior surface of coaracoid process of scapula
innervation-medial pectoral nerve
main action-stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall

Front 89

Wht is the proximal, distal, innervation and main action of the subclavius?

Back 89

proximal-junction of 1st rib and its costal cartilage
distal-inferior surface of middle third of clavicle
innervation-nerve to subclavius
main action-anchros and depresses clavicle

Front 90

What is the proximal, distal, innervation and main action of the serratus anterior?

Back 90

proximal-external surfaces of lateral parts of 1st-8th ribs
distal-anterior surface of medial border of scapula
innervation-long thoracic nerve (C5-C7)
main action-protracts scapula and holds it against thoracic wall, rotates scapula

Front 91

What is the proximal, distal, innervation and main action of the trapezius?

Back 91

proximal-medial third of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae
distal-lateral third of clavicle, acromion and spine of scapula
innervation-accessory nerve (CN XI, motor fibers) and C3-C4 spinal nerves (pain and proprioception)
main action-descending part elevates, ascending part depresses and middle part retracts scapula, descending and ascending parts act together to rotate glenoid cavity superiorly

Front 92

What is the proximal, distal, innervation and main action of the latissimus dorsi?

Back 92

proximal-spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs
distal-floor of intertubercular groove of humerus
innervation-thoracodorsal nerve (C6-C8)
main action-extends, adducts, and medially rotates humerus, raises body toward arms during climbing

Front 93

What is the proximal, distal, innervatrion and main action of the levator scapulae?

Back 93

proximal-posterior tubercles of transverse process of C1-C4 vertebrae
distal-medial border of scapula superior to root of spine
innervation-dorsal scapular (C5) and cervical (C3,C4) nerves
main action-elevates scapulae and tilts its glenoid cavity inferiorly by rotating scapula

Front 94

what is the proximal, distal, innervation and main action of the rhomboid minor and major?

Back 94

proximal-minor (nuchal ligament, spinous processes of C7-T1), major (spinous processes of T2-T5)
distal-minor (smooth triangular area at medial end of scapular spine), major (medial border of scapula fromlevel of spine to inferior angle)
innervation-dorsal scapular nerve (C4, C5)
main action-retract scapula and rotate it to depress glenoid cavity, fix scapula to thoracic wall

Front 95

What is the proximal, distal, innervation and main action of the deltoid?

Back 95

1. proximal-lateral third of clavicle, acromion and spine of scapula
2. distal-deltoid tuberosity of humerus
3. innervation-axillary nerve
4. main action-anterior part (flexes and medially rotates arm), middle part (abducts arm), posterior part (extends and laterally rotates arm)

Front 96

What is the proximal, distal, innervation and main action of the supraspinatus?

Back 96

1. proximal-supraspinous fossa of scapula
2. distal-superior facet of greater tubercle of humerus
3. innervation-suprscapular nerve
4. main action-initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles

Front 97

What is the proximal, distal, innervation and main action of the infraspinatus?

Back 97

1. proximal-infraspinous fossa of scapula
2. distal-middle facet of greater tubercle of humerus
3. innervation-suprascapular nerve
4. main action-laterally rotate arm, help hold humeral head in glenoid cavity of scapula

Front 98

What is the proximal, distal, inneravtion and main action of the teres minor?

Back 98

1. proximal-middle part of lateral border of scapula
2. distal-inferiorinferior facet of greater tubercle of humerus
3. innervation-axillary nerve
4. main action-laterally rotate arm, help hold humeral head in glenoid cavity of scapula

Front 99

What is the proximal, distal, inneravtion and main action of the teres major?

Back 99

1. proximal-posterior surface of inferior angle of scapula
2. distal-medial lip of intertubercular groove of humerus
3. innervation-lower subscapular nerve
4. main action-adducts and medially rotates arm

Front 100

What is the proximal, distal, innervation and main action of subscapularis?

Back 100

1. proximal-subscapular fossa
2. distal-lesser tubercle of humerus
3. innervation-upper and lower subscapular nerves
4. main action-medially rotates and adduct arm, helps hold humeral head in glenoid cavity

Front 101

What muscles of upper limb allow for elevation of the scapula?

Back 101

trapezius (superior part), levator scapulae, rhomboids

Front 102

what muscles of the upper limb allow for depression of the scapula?

Back 102

gravity, pec major, latissimus dorsi, trapezius, serratus anterior, pec. minor

Front 103

What muscles allow for protraction of the scapula?

Back 103

serratus anterior, pec major, pec minor

Front 104

What muscles allow for retraction of the scapula?

Back 104

trapezius, rhomboids, lattissimus dorsi

Front 105

what muscles allow for upward rotation of the scapula?

Back 105

trapezius, serratus anterior

Front 106

what muscles allow for downward rotation of the scapula?

Back 106

gravity, levator scapulae, rhomboids, latissimus dorsi, pec major

Front 107

Describe the humerus.

Back 107

largest bone in the upper limb, proximal end has a head, surgical and anatomical necks and greater and lesser tubercles

Front 108

What does the humerus articulate with?

Back 108

articulates with the scapula at the glenohumeral joint via its head and the radius and ulna at the elbow joint

Front 109

What purpose do the necks of the humerus have?

Back 109

anatomical neck separates the head from the greater and lesser tubercle, surgical neck is narrow part distal to the head and tubercles, common site of fracture

Front 110

Describe where the greater and lesser tubercles are found and what their functions are.

Back 110

the junction of the head and neck with the shaft of the humerus is indicated by the tubercles, provide attachment and leverage to some scapulohumeral muscles, greater is at the lateral margin and the lesser projects anteriorly from the bone

Front 111

Where is the intertubercular groove of the humerus?

Back 111

separates the tubercles and provides protected passage for the slender tendon of the long head of the biceps muscle

Front 112

What is the importance of the radial (spiral) groove of the humerus? Where is it found?

Back 112

groove for the radial nerve and deep artery (profunda brachii) of the arm (spiral groove), these pass anterior to the long and between the medial and lateral heads of the triceps, groove wraps around humerus, found on the posterior portion of the shaft of the humerus

Front 113

What are the different epicondyles found on the humerus?

Back 113

the inferior end of the humeral shaft widens to form the sharp medial and lateral supraepicondylar ridges, these end distally as the medial (funny bone) and lateral epicondyles which provide for muscle attachment, nerve runs through here

Front 114

What makes up the condyle of the humerus? What is its importance?

Back 114

made up by the distal end of the humerus, including the trochlea, capitulum and the olecranon, coronoid and radial fossae, condyle has two articular surfaces (lateral capitulum for articulation with the head of the radius and a medial, spool shaped trochlea for articulation with the proximal end of the ulna)

Front 115

Describe the coronoid fossa of the humerus.

Back 115

anterior, receives the coronoid process of the ulna during full flexion of the elbow

Front 116

Describe the olecranon fossa of the humerus.

Back 116

posterior, accommodates the olecranon of the ulna during full extension of the elbow, deep depression

Front 117

Describe the radial fossa of the humerus.

Back 117

superior to the capitulum anteriorly, accommodates the edge of the head of the radius when the forearm is fully flexed

Front 118

What allows for supination and pronation of the forearm? Why is this important?

Back 118

the forearm is made of two parallel bones (radius and ulna), radius can pivot about the ulna allowing for supination and pronation, makes it possible to rotate the hand when the elbow is flexed

Front 119

Describe the ulna.

Back 119

is the stabilizing bone of the forearm, is the medial and longer of the two forearm bones, massive proximal end for articulation

Front 120

What does the ulna articulate with?

Back 120

humerus superiorly and radius laterally

Front 121

Describe the ulnar projections involved with the articulation with the humerus.

Back 121

1. olecranon-projects proximally from is posterior aspect, serves as a short lever for extension of elbow
2. coronoid process-projects anteriorly

Front 122

What forms the trochlear notch?

Back 122

formed by the olecranon and coronoid processes, resembles the jaws of a crescent wrench as it grips the trochlea of the humerus

Front 123

What movements are allowed by the articulation between the ulna and humerus?

Back 123

allows flexion and extension of the elbow joint, also a small amount of abduction-adduction occurs during pronation and supination of the forearm

Front 124

Where is the ulnar tuberostiy and what is its significance?

Back 124

inferior to the coronoid process, is attachment of the tendon of the brachialis muscle, attachment for forearm flexors

Front 125

Describe the articulation between the ulna and radius.

Back 125

ulna has a radial notch which receives the head of the radius, radial notch is where the radius spins on the ulna, radius also spins distally on the ulna

Front 126

Describe the ulnar styloid process.

Back 126

a small, conical process found on the head of the ulna, the ulna does not reach the wrist and does not participate in its movements

Front 127

Describe the radius.

Back 127

is the lateral and shorter of the two forearm bones, has a short head, neck and medially directed tuberosity on its proximal end

Front 128

Describe the head of the radius and its articulations.

Back 128

has a smooth superior aspect that is concave for the articulation with the capitulum of the humerus during flexion and extension of the elbow joint, also articulates with the radial notch of the ulna so head is covered with articular cartilage, encircled by a ligament, can pull head of radius out of ligament in children

Front 129

Describe the radial tuberosity.

Back 129

is oval in shape, is distal to the medial part of the neck and demarcates the proximal end of the radius from the shaft, attachment site for forearm muscles

Front 130

Describe the radial styloid process.

Back 130

is the termination point for the lateral aspect of the body of the radius, larger than the ulnar styloid process and extends further distally

Front 131

Describe the dorsal tubercle of the radius.

Back 131

projects dorsally, lies between otherwise shallow grooves for the passage of the tendons of the forearm muscles

Front 132

What is the interosseous membrane of the forearm and what is its significance?

Back 132

is a thin fibrous membrane, run an oblique course, passing inferiorly from the radius as they extend medially to the ulna, they are positioned to transmit forces received by the radius to the ulna for transmission to the humerus

Front 133

What bones and processes make up the elbow?

Back 133

1. humerus-medial epicondyle, lateral epicondyle, capitulu, trochlea, coronoid fossa
2. ulna-coronoid process, olecranon, radial notch
3. radius-head, neck, tuberosity

Front 134

What bones make up the wrist (carpus)?

Back 134

composed of eight carpal bones, from lateral to medial:
1. proximal row-SLTP (scaphoid (oid first in the 1st row), lunate, triguetrum, pisiform)
2. distal row-TTCH (trapezium (by the thumb), trapezoid (oid second in the 2nd row), capitate, hamate (has hook on it)

Front 135

What pneumonic can be used to remember the carpal bones?

Back 135

some lovers try positions that they can’t handle

Front 136

Which carpal bone has poor blood supply?

Back 136

scaphoid, when it is fractured by athletes have to be careful because doesn’t always show up in first week of fracture, if don’t pick up fracture can undergo avascular necrosis

Front 137

Describe the metacarpus.

Back 137

forms the skeleton of the palm of the hand between the carpus and the phalanges, composed of five metacarpal bones each consisting of a base, shaft and head, proximal bases articulate with the carpal bones and the distal heads articulate with the proximal phalanges and form the knuckles

Front 138

Describe the 1st and 3rd metacarpal.

Back 138

1st (of the thumb) is the thickest and shortest of these bones, 3rd is distinguished by a styloid process on the lateral side of its base

Front 139

Describe the phalanges.

Back 139

each digit has three phalanges except for the first (thumb) which has only two, each phalanx has a base proximally, a shaft and distal head, proximal phalanges are largest and distal are smallest, shafts taper distally, terminal phalanges are flattened and expanded at their distal ends underlying the nail beds

Front 140

What does the transverse metacarpal ligament do?

Back 140

it stabilizes the hand in single metacarpal fractures

Front 141

Describe fracture of the scaphoid.

Back 141

most frequently fractured carpal bone, often results from a fall on the palm when the hand is abducted, initial radiographs may not show fracture, union of fractured parts may take 3 months, may need to fuse carpals surgically (arthrodesis), more lateral part gets more blood, blood then goes to medial part which gets less blood supply and becomes necrotic first

Front 142

Describe shoulder dislocation.

Back 142

occurs when head of humerus slides off glenoid process, if abduct shoulder, susceptible to dislocation in an AP direction, may damage axillary nerve, may also musculocutaneous nerve, can check axillary nerve on shoulder and musculocutaneous on anterior forearm, when replace dislocated shoulder should use muscle relaxant because muscles are pulling it into axillary fossa

Front 143

Describe colles fracture.

Back 143

fracture of distal end of radius, most common forearm fracture in people over 50, heals well, is a complete transverse fracture of the distal 2 cm of the radius, distal fragment is displaced dorsally and is often comminuted, results from forced dosiflexion of the hand, usually as the result of trying to ease a fall by outstretching the upper limb, force transferred from the radius (radiocarpal joint) to ulna and ulna to radioulnar joint bec. of direction of fibers of interosseus membrane

Front 144

What are the axis of rotation for the glenohumeral joint?

Back 144

1. AP-ab and adduction
2. vertical-rotation
3. transverse-flexsion and extension

Front 145

What are the axis of rotation for the humeroulnar joint?

Back 145

1. transverse-flexion and extension
2. is the main articulation of the elbow

Front 146

What aer the axis of rotation for the humeroradial joint?

Back 146

1. transverse-flexion and extension
2. vertical rotation-allows pronation and supination

Front 147

What are the axis of rotation for the radioulnar joint?

Back 147

1. vertical rotation-pronation and supination

Front 148

What are the axis of rotation for the radiocarpal joint?

Back 148

1. transverse-flexion and extension
2. AP-abduction and adduction (ulnar abduction and radial abduction)

Front 149

What is the axis of rotation for the carpometacarpal joints?

Back 149

1st and 5th are significant, 1st (weakest but most mobile) is multiaxial and allows abduction-adduction, flexion-extension and rotation (for opposition), found between carpal bone at the distal row

Front 150

Why is movement for the thumb different from the other fingers at the carpometacarpal joint?

Back 150

thumb is rotated 90 degrees out of the same plane that the fingers are in, what was flexion and extension for fingers is now 90 degrees off, what was ab-adduction is now 90 degrees off, rotated out of transverse plane into AP plane

Front 151

What is the axis of rotation for the metacarpalphalangeal joint?

Back 151

2-5 are biaxial (flexion-extension and ab-adduction), 1 is uniaxial (only flexion-extension)

Front 152

What is the axis of rotation for the interphalangeal joint?

Back 152

between PIP and DIP (proximal and distal interphalangeal joint), uniaxial, transverse-flexion and extension

Front 153

Describe the course of the axillary artery.

Back 153

begins at the lateral border of the 1st rib as the continuation of the subclavian artery and ends at the inferior border of the teres major, passes posterior to pec minor into arm and becomes the brachial artery when it passes inferior border of teres major (where it reaches the humerus)

Front 154

What are the three divisions of the axillary artery by the pec minor (part number indicates number of its branches)?

Back 154

1. 1st part-between the lateral border of the 1st rib and the medial border of the pec minor (from subclavian to upper border of pec minor), enclosed in the axillary sheath and has one branch (superior thoracic artery)
2. 2nd part-lies posterior to pec minor and has two branches (throacoacromial and lateral thoracic arteries) which pass medial and lateral to the muscle, from upper border of pec minor to lower border of pec minor
3. 3rd part-extends from the lateral border of the pec mino to inferior border of teres major, 3 branches (subscapular artery, anterior circumflex humeral and posterior circumflex humeral arteries), from lower border of pec minor to lower border of teres major

Front 155

Where does the pec minor attach?

Back 155

coracoid process

Front 156

Describe the course of the superior thoracic artery.

Back 156

runs anteromedially along superior border of pectoralis minor, then passes between it and pec major to thoracic wall, helps supply 1st and 2nd intercostal spaces and superior part of serratus anterior, anastomoses with intercostal and/or internal thoracic arteries

Front 157

Describe the course of the thoracoacromial trunk.

Back 157

curls around superomedial border of pec minor, pierces costocoracoid membrane (clavipecotral fascia) divides into four branches (pectoral, deltoid, acromial and clavicular)

Front 158

Describe the course of the lateral thoracic artery.

Back 158

descends along axillary border of pec minor, follows it onto thoracic wall supplying lateral aspect of breast, pectoral, serratus anterior and intercostal muscles, axillary lymph nodes, runs with a nerve (nerve to serratus anterior=long thoracic nerve, responsible for winged scapula)

Front 159

Describe the course of the circumflex humeral (anterior and posterior) artery.

Back 159

encircle surgical neck of humerus, anastomosing with each other laterally, larger posterior branch traverses quadrangular space, anterior is smaller and gives off ascending branch that supplies shoulder, posterior is larger and supplies glenohumeral joint and surrounding muscles, larger associated with axillary nerve

Front 160

Describe the course of the subscapular artery.

Back 160

descends from level of inferior border of subscapularis along lateral border of scapula, dividing within 2-3 cm into terminal branches, the circumflex scapular and thoracodorsal arteries, greatest diameter, smallest length

Front 161

Describe the course of the circumflex scapular artery.

Back 161

curves around lateral border of scapula to enter infraspinous fossa, anastomosing with suprascapular artery, often larger terminal branch, supplies muscles on the dorsum of the scapula

Front 162

Descrivbe the course of the thoracodorsal artery.

Back 162

continues course of subscapular artery, descending with thoracodorsal nerve to enter apex of latissimus dorsi, participates in the arterial anastomoses around the scapula, associated with lattisimus dorsi, travels with the thoracodorsal nerve

Front 163

Describe the anastomoses around the scapula.

Back 163

gets branches form the thyrocervical trunk, vessels that supply this are the dorsal scapular, suprascapular and subscapular arteries, important for ligation of a lacerated subclavian or axillary artery, can tie off axillary artery and still have flow to the upper limb

Front 164

What does the anastomoses around the scapula supply?

Back 164

suprascapular notch, transverse ligament of scapula, suprascapular artery, posterior circumflex humeral artery

Front 165

Describe the anastomosis around the elbow.

Back 165

the brachial artery can be ligated distal to the profunda due to the anastomosis between numerous recurrents and collaterals at the elbow, normally see anastomosis where joints are present, branches that come down from above are collaterals and branches from below are recurrents

Front 166

Describe the arterial supply of the hand.

Back 166

because hand is placed in multiple positions, it requires an abundance of highly branched and anastomosing arteries so that oxygenated blood is generally available to all parts in all positions, the ulnar and radial arteries and their branches provide all the blood to the hand

Front 167

Describe the ulnar artery.

Back 167

enters the hand anterior to the flexor retinaculum between the pisiform and the hook of the hamate via the ulnar canal, lateral to ulnar nerve, divides into two terminal branches (superficial palmar arch and deep palmar branch

Front 168

Describe the radial artery.

Back 168

curves dorsally around the scaphoid and trapezium and crosses the floor of the anatomical snuff box, enters palm by passing between heads of 1st dorsal interosseous muscle and then turns medially, ends by anastomosing with the deep branch of the ulnar artery to form the deep palmar arch

Front 169

What is the origin, course and branches of the superficial palmar arch?

Back 169

1. origin-direct continuation of ulnar artery, arch is completed on lateral side by superficial branch of radial artery or another of its branches
2. course-curves laterally deep to palmar aponeurosis and superifical to long flexor tendons, curve of arch lies across palm at level of distal border of extended thumb
3. branches-gives rise to three common palmar digital arteries that anastomose with the palmar metacarpal arteries from the deep palmar arch, common palmar digital artiers divides into a pair of proper palmar digital arteries that run on the adjacent side of 2nd-4th finger

Front 170

What is the origin, course and branches of the deep palmar arch?

Back 170

1. origin-direct continuation of radial artery, arch is completed on medial side by deep branch of ulnar artery
2. course-curves medially, deep to long flexor tendons, is in contact with bases of metacarpals
3. branches-gives rise to three palmar metacarpal arteries and the princes pollicis artery, radialis indicis (which passes along lateral side of index finger) may come from radial artery or princes pollicis

Front 171

What is the Allen test?

Back 171

tests the important anastomosis between the radial and ulnar arteries in the palm, done when trying to do radial punctures for blood gases, makes sure that radial artery is not the main artery to the hand, some people don’t have good collateral flow

Front 172

How is the Allen test done?

Back 172

get hand active and red w/ good flow, squeeze it down and open it and see it blanch for a few secs., take two fingers and press on radial and ulnar arteries, and open each individually and see how long it takes to blanch

Front 173

Where do the lymphatics of the upper limb drain?

Back 173

all the lymphatics except those following the cephalic vein (more superficial) drain to the axillary nodes (humeral group), cephalic vein drains into the deltopectoral nodes, ultimately they all drain into the apical nodes

Front 174

What is the definition of the axilla?

Back 174

the space below the shoulder joint, bounded by the pectoralis major anteriorly, the latissimus dorsi posteriorly, seratus anterior medially and humerus laterally

Front 175

Describe the axilla.

Back 175

pyramidal space inferior to the glenohumeral joint, provides a passageway for the neurovascular structures that serve the upper limb, brachial plexus travels through here

Front 176

Describe the course of the neurovascular structures through the axilla.

Back 176

1. pass superiorly via the cervicoaxillary canal to the root of the neck
2. anteriorly via the clavipectoral triangle to the pectoral region
3. inferiorly and laterally into the limb itself
4. posteriorly via the quadrangular space to the scapular region
5. inferiorly and medially along the thoracic wall to the inferiorly placed axioappendicular muscles

Front 177

Describe the apex of the axilla.

Back 177

is the cervicoaxillary canal, passageway between the neck and axilla, bounded by the 1st rib, clavicle and superior edge of the scapula, arteries, veins, lymphatics and nerves traverse this superior opening of the axilla to pass to or form the arm

Front 178

Describe the base of axilla.

Back 178

formed by the concave skin, subQ tissue and axillary fascia extending from the arm to the thoracic wall, forming the axillary fossa (armpit), bounded by the anterior and posterior axillary folds, thoracic wall and medial aspect of the arm

Front 179

Describe the anterior wall of the axilla.

Back 179

has two layers, formed by the pec major and pec minor and the pectoral and clavicopectoral fascia associated with them, inferiormost part is the anterior axillary fold, may be grasped between the fingers, is formed by the pec major as it bridges from thoracic wall to humerus and the overlying integument, little bit of deltoid as well

Front 180

What fascia invests pectoralis major and minor?

Back 180

calvipectoral fascia, very important because there is a point where the cephalic vein penetrates and the fascia becomes the axillary fascia, forms the floor of the axilla, blends with the fascia of the arm, this is why when you abduct forms a pit in the axilla, is a continuation of the lateral border of the pectoralis muscle, thoracoacromial artery also goes thorugh it

Front 181

Describe the posterior wall of the axilla.

Back 181

formed chiefly by the scapula and subscapularis on its anterior surface and inferiorly by the teres major and latissimus dorsi, the posterior axillary fold is the inferiormost part of the posterior wall, extends farther inferiorly than the anterior wall and is formed by the latissimus dorsi, teres major and overlying integument

Front 182

What are the contents of the posterior wall of the axilla?

Back 182

has thoracodorsal artery + nerve (going to the latissimus dorsi) going through it, quadrangular space with axillary nerve and posterior circumflex humeral artery, anterior circumflex humeral artery, suprascapular artery and nerve and transverse scapular ligament

Front 183

Describe the medial wall of the axilla.

Back 183

is formed by the thoracic wall (1st-4th ribs and intercostal muscles) and the overlying serratus anterior, has lateral thoracic artery and runs superficial and with the long thoracic nerve

Front 184

What leads to winged scapula?

Back 184

damage to the long thoracic nerve, when push on arm scapula does not hold snug against the thoracic cage

Front 185

Describe the lateral wall of axilla.

Back 185

is a narrow bony wall formed by the intertubercular groove in the humerus

Front 186

What are the contents of the axilla?

Back 186

contains axillary blood vessels, lymphatic vessels and several groups of axillary lymph nodes all embedded in a matrix of axillary fat, contains large nerves that make up the cords and branches of the brachial plexus, the neurovascular structures are ensheathed in a sleeve-like extension of cervical fascia (axillary sheath)

Front 187

Describe the orientation of the contents of the axilla.

Back 187

all the structure in the axilla are oriented around the axillary artery, have branches of the brachial plexus called the cord that is arranged according to their position relative to axillary artery, axillary vein is medial to artery

Front 188

Describe the brachial plexus.

Back 188

gives rise to most of the nerves in the upper limb, begins in neck and extends into the axilla, almost all branches arise in the axilla, formed by the anterior (ventral) rami (roots) of C5-T1, these roots usually pass through the gap between the anterior and middle scalene muscles with the subclavian artery, sympathetic fibers carried by each root are received from the gray rami of the middle and inferior cervical ganglia as the roots pass between the scalene

Front 189

what are the three trunks of the brachial plexus?

Back 189

formed by the 5 roots to form three trunks, formed at the inferior part of the neck, include the superior (C5-C6), middle (C7) and inferior (C8-T1), each trunk divides into anterior and posterior divisions as they pass through the cervicoaxillary canal posterior to the clavicle

Front 190

What do the different divisions supply?

Back 190

each trunk divides into an anterior and posterior division, so there are 3 anterior and 3 posterior divisions, anterior supply anterior (flexor) compartments of the upper limb and posterior supply the posterior (extensor) compartments, the divisions of the trunk form three cords of the brachial plexus, embryologically, posterior divisions are devoted to muscles that originated in the posterior compartment of the arm (extensor group)

Front 191

What are the three cords of the brachial plexus?

Back 191

1. anterior divisions of the superior and middle trunks unite to form the lateral cord
2. anterior divisions of the inferior trunk continues as the medial cord
3. posterior divisions of all three turnks unite to form the posterior cord
cord names bear the relationship to the second part of the axillary artery, then divide into the terminal branches

Front 192

What are the terminal branches of the brachial plexus?

Back 192

cords divide into terminal branches, have branch from the lateral cord (musculocutaneous), branch from the medial cord (ulnar), combo from the two forming the median, posterior cord gives off axillary and radial

Front 193

What is the pneumonic for remembering the brachial plexus?

Back 193

Randy Travis Drinks Cold Beer (roots, trunks, divisions, cords, branches) (C5-T1, U-M-L, A&P, Lat-Med-Pos)

Front 194

What is the segmental innervation of the upper limb (myotome)?

Back 194

C5-C6 for shoulder joint, C6-C7 for elbow joint, C7-C8 for wrist, and C8-T1 for fingers and carpalmetacarpal joints

Front 195

What is the dermatome map of the upper limb?

Back 195

C6 for thumb, C8 for little finger, good for central lesions

Front 196

Describe the peripheral nerve innervation of the upper limb.

Back 196

cannot get this info from myotome or dermatome map, different on its own, each nerve innervates a specific area

Front 197

Describe the peripheral innervation of the hand.

Back 197

innervated by the median nerve, ulnar nerve and radial nerve
1. median nerve-on the anterior surface of the hand, does 3.5 digits, thumb, index, middle and ½ of ring, also continues over the top of the dorsum for 3.5 digits, to test median nerve check distal tip of middle finger
2. ulnar nerve-1.5 fingers, ½ ring and pinkie, tip of little finger is always ulnar
3. radial nerve-3.5 on the dorsal side to distal extremity, point always radial is right over meaty area between first and second metacarpal

Front 198

How does the calvicle divide the brachial plexus?

Back 198

the clavicle divides the plexus into supraclavicular and infraclavicular parts

Front 199

Describe the supraclavidular branch of the brachial plexus.

Back 199

has four branches, arise from the roots (anterior rami) and trunks of the brachial plexus (dorsal scapular nerve, long thoracic nerve, nerve to subclavius and suprascapular nerve)

Front 200

Describe the muscular branches of the brachial plexus.

Back 200

there are also unnamed muscular branches that arise from all five roots of the plexus which supply the scalene and longus colli muscles

Front 201

Describe the infraclavicular branches of the brachial plexus.

Back 201

arise from the ords of the brachial plexus and are approachable through the axilla, 3 branches arise from the lateral cord, whereas the medial and posterior cords each give rise to 5 branches

Front 202

Describe the origin, course and sturcutres innervated by the dorsal scapular nerve.

Back 202

1. origin-posterior aspect of anterior ramus of C5 with a freq. contribution from C4
2. course-pierces middle scalene, descends deep to levator scapulae and rhomboids
3. innervation-rhomboids, occasionally supplies levator scapulae

Front 203

Describe the origin, course and sturcutres innervated by the long thoracic nerve.

Back 203

1. posterior aspect of anterior rami of C5-C7
2. passes through cervicoaxillary canal, descending postlerior to C8 and T1 roots of plexus, runs inferiorly on superficial surface of serratus anterior
3. serratus anterior

Front 204

Describe the origin, course and sturcutres innervated by the suprascapular nerve.

Back 204

1. superior trunk, receiving fibers from C4-C6
2. passes laterally across lateral cervical region, superior to brachial plexus, then through scapular notch inferior to superior transverse cervical ligament
3. supraspinatus and infraspinatus muscles, glenohumeral joint

Front 205

Describe the origin, course and sturcutres innervated by the subclavian (nerve to subclavisu) nerve.

Back 205

1. superior trunk receiving fibers from C4-C6
2. descends posterior to clavicle and anterior to brachial plexus and subclavian artery, often giving an accessory root to phrenic nerve
3. subclavius and sternoclavicular joint (accessory phrenic innervates diaphragm

Front 206

Describe the origin, course and sturcutres innervated by the lateral pectoral nerve.

Back 206

1. side branch of lateral cord, receiving fribers from C5-C7
2. piereces costocoracoid membrane to reach deep surface of pectoral muscles, a communicating branch to the medial pectoral nerve passes anterior to axillary artery and vein
3. primarily pectoralis major but some lateral pectoral nerve fibers pass to pectoralis minor via branch to medial pectoral nerve

Front 207

Describe the origin, course and sturcutres innervated by the musculocutaneous nerve.

Back 207

1. terminal branch of lateral cord, receiving fibers from C5-7
2. exits axilla by piercing coracobrachialis, descends between biceps brachii and brachialis, supplying both, continues as lateral cutaneous nerve of forearm
3. muscles of anterior compartment of arm (coracohrachialis, biceps brachii and brachialis), skin of lateral aspect of forearm

Front 208

Describe the origin, course and sturcutres innervated by the median nerve.

Back 208

1. lateral root of median nerve is a terminal branch of lateral cord, medial root of median nerve is a terminal branch of medial cord
2. lateral and medial roots merge to form median nerve lateral to axillary artery, descends through arm adjacent to brachial artery, with nerve gradually crossing anterior to artery to lie medial to artery in cubital fossa
3. muscles of anterior forearm compartment (except for flexor carpi ulnaris and ulnar half of flexor digitorum profundus), five intrinsic muscles in thenar half of palm and palmar skin

Front 209

Describe the origin, course and sturcutres innervated by the medial pectoral nerve.

Back 209

1. side branches of medial cord, receiving fibers from C8-T1
2. passes between axillary artery and vein, then peireces pectoralis minor and enters deep surface of pectoralis major, although it is called medial for its origing form medial cord it lies lateral to lateral pectoral nerve
3. pectoralis minor and sternocostal part of pectoralis major

Front 210

Describe the origin, course and sturcutres innervated by the medial cutaneous nerve of arm (medial brachial).

Back 210

1. side branches of medial cord, receiving fibers from C8-T1
2. smallest nerve of plexus, runs along medial side of axillary and brachial veins, communicates with intercostobrachial nerve
3. skin of medial side of arm, as far distal as medial epicondyle of humerus and olecranon of ulna

Front 211

Describe the origin, course and sturcutres innervated by the median cutaneous nerve of forearm (medial antebrachial cutaneous).

Back 211

1. side branches of medial cord, receiving fibers from C8, T1
2. initially runs with ulnar nerve but peireces deep fascia with basilica vein and enters subQ tissue dividing into anterior and posterior branches
3. skin of medial side of forearm as far distal as wrist

Front 212

Describe the origin, course and sturcutres innervated by the ulnar nerve.

Back 212

1. larger terminal branch of medial cord, receiving fibers from C8, T1 and C7
2. descends medial arm, passes posterior to medial epicondyle of humerus, then descends ulnar aspect of forearm to hand
3. flexor carpi ulnaris and ulnar half of flexor digitorum profundus, most intrinsic muscles of hand, skin of hand medial to axial line of digit 4

Front 213

Describe the origin, course and sturcutres innervated by the upper subscapular nerve.

Back 213

1. side branch of posterior cord, C5
2. passes posteriorly entering subscapularis directly
3. superior portion of subscapularis

Front 214

Describe the origin, course and sturcutres innervated by the lower subscapular nerve.

Back 214

1. side branch of posterior cord, C6
2. passes inferolaterally, deep to subscapular artery and vein
3. inferior portion of subscapularis and teres major

Front 215

Describe the origin, course and sturcutres innervated by the thoracodorsal (middle subscapulars) nerve.

Back 215

1. side branch of posterior cord, C6-8
2. arises between upper and lower subscapular nerves and runs inferolaterally along posterior axillary wall to apical part of latissimus dorsi
3. latissimus dorsi

Front 216

Describe the origin, course and sturcutres innervated by the axillary nerve.

Back 216

1. terminal branch of posterior cord, C5, C6
2. exits axillary fossa posteriorly, passing through quadrangular space with posterior circumflex humeral artery, gives rise to superior lateral brachial cutaneous nerve, then winds around surgical neck of humerus deep to deltoid
3. glenohumeral joint, teres minor and deltoid, skin of superolateral arm

Front 217

Describe the origin, course and sturcutres innervated by the radial nerve.

Back 217

1. larger terminal branch of posterior cord, C5-T1
2. exits axillary fossa posterior to axillary artery, passes posterior to humerus in radial groove with deep brachial artery, between lateral and medial heads of triceps, perforates lateral intermuscular septum, enters cubital fossa, dividing into superficial and deep radial nerves
3. all muscles of posterior compartments of arm and forearm, skin of posterior and inferolateral arm, posterior forearm and dorsum of hand lateral to axial line of digit

Front 218

Describe the compartmental innervation of muscles by major branches of the brachial plexus.

Back 218

1. anterior compartment-anterior arm (musculocutaneous), anterior forearm (all median except FCU (flexor carpi ulnaris) + 2 heads of FDP (flexor digitorum profundus)) (ulnar), anterior hand (all ulnar except thenar (thumb) compartment muscles + lumbricals to the functional midline on radial side (median))
2. posterior compartment-shoulder, deltoid and teres minor (axillary), posterior arm and forearm (radial)

Front 219

What are the branches from the roots of the brachial plexus?

Back 219

dorsal scapular and long thoracic

Front 220

What are the branches from the trunks of the brachial plexus?

Back 220

suprascapular

Front 221

what are the branches from the cords of the brachial plexus?

Back 221

1. lateral-lateral pectoral
2. posterior-upper, middle (thoracodorsal) and lower subscapularis
3. medial-medial pectoral (into pecotralis muscle), medial brachial (medial side of arm) and medial antebrachial cutaneous (cutaneous to forearm)

Front 222

What aer the terminal branches of the brachial plexus?

Back 222

radial, axillary, muscular cutaneous, ulnar, median

Front 223

What is Erb-Duchenne Paralysis?

Back 223

damage to upper trunk of the brachial plexus, shoulder movements are affected most dramatically, get paralysis of the muscles supplied by C5 and C6 (deltoid, biceps, brachialis and brachioradialis), presents as an upper limb with an adducted shoulder, medially rotated arm and extended elbow, happens if lateral bend neck and shoulder down

Front 224

What is Erb-Duchenne palsy?

Back 224

muscles of shoulder and upper arm chiefly affected, elbow extended (and wrist may be flexed) but grasp is normal, caused from injuries of upper brachial plexus or its nerve roots (C5, C6), injuries of C4 root may cause phrenic nerve paralysis and respiratory distress, wipeout radial and axillary from C5 and C6, will take deltoid out completely

Front 225

What is Klumpke’s paralysis?

Back 225

damage of lower trunk of the brachial plexus, hand movements are affected most dramatically, may occur when upper limb is suddenly pulled superiorly, injure C8-T1 and may avulse the roots of the spinal nerves from the spinal cord, short muscles of hand are affected and may lead to claw hand

Front 226

what is Klumpke’s palsy?

Back 226

muscles of forearm and hand chiefly affected, grasp weak and affected limb small, Horner’s syndrome present, due to interruption of fibers to cervical sympathetic trunk (from injury to T1 since that gives sympathetics)

Front 227

What is scapular winging?

Back 227

damage to long thoracic nerve, serratus anterior, weakened abduction over 90 degrees

Front 228

What is the importance of fascial planes in the upper limb?

Back 228

allows for the division of the muscles into different compartments (anterior and posterior)

Front 229

What is compartment syndrome?

Back 229

if the pressure of a compartment goes up (say due to bad bruising), blood supply and nerve supply in the compartment these can be cut off and can cause permanent damage as seen in LMN syndrome (muscle wasting), if goes up, can filet open and allow for the swelling to go down to reduce the compression

Front 230

What muscles are in the anterior compartment of the arm?

Back 230

biceps brachii (long and short head), coracobrachialis, brachialis, all innervated by the musculocutaneous nerve (from C5-C7)

Front 231

What is the proximal attachment, distal attachment, innervation and main action of the biceps brachii?

Back 231

1. proximal attachment-short head (tip of coracoid process of scapula), long head (supraglenoid tubercle of scapula, more lateral)
2. distal attachment-tuberosity of radius and fascia of forearm via bicipital aponeurosis
3. innervation-musculocutaneous nerve (C5, C6)
4. main action-supinates forearm and when it is supine, flexes forearm (powerful), short head resists dislocation of shoulder

Front 232

What is the proximal attachment, distal attachment, innervation and main action of the coracobrachialis?

Back 232

1. proximal attachment-tip of coracoid process of scapula
2. distal attachment-middle third of medial surface of humerus
3. innervation-musculocutaneous nerve (C5-C7)
4. main action-helps fix and adduct arm, resists dislocation of shoulder
has a good landmark where the musculocutaneous nerve passes right through it

Front 233

what is the proximal attachment, distal attachment, innervation and main action of the brachialis?

Back 233

1. proximal attachment-distal half of anterior surface of humerus
2. distal attachment-coronoid process and tuberosity of ulna
3. innervation-musculocutaneous nerve
4. main action-flexes forearm in all positions (powerful)

Front 234

what is the difference between the brachialis and biceps brachii?

Back 234

there attachment, when biceps works, have to unwind (supinate) when flexing, all power is in the supinated position

Front 235

What muscles are in the posterior compartment of the arm?

Back 235

3 heads of the tricpes brachii, innervated by the radial nerve

Front 236

What is the proximal attachment, distal attachment, innervation and main action of the triceps brachii?

Back 236

1. proximal attachment-
a. long head-infraglenoid tubercle of scapula, only head to cross the glenohumeral joint
b. lateral head-posterior surface of humerus, superior to radial groove
c. medial head-posterior surface of humerus, inferior to radial groove
2. distal attachment-proximal end of olecranon of ulna and fascia of forearm
3. innervation-radial nerve (C6-C8)
4. main action-chief extensor of forearm, long head resists dislocation of humerus, esp. important during abduction

Front 237

What happens with damage to the terminal branches?

Back 237

1. axillary nerve-severely weakened abduction, weakened lateral rotation
2. musculocutaneous nerve-no forearm flexion, weakened arm flexion

Front 238

What are the groups in the anterior forearm?

Back 238

there is a superficial and deep group

Front 239

What does the interosseus membrane do?

Back 239

it transfers energy from the ulna and radius up to the humerus (from the radiocarpal joint to humeroulnar joint), is a shock absorber

Front 240

What is the blood supply of the forearm?

Back 240

main areteries are the ulnar and radial arteries which usually arise opposite the neck of the radius in the inferior part of the cubital fossa as terminal branches of the brachial artery

Front 241

Describe the brachial arery.

Back 241

main blood supply to the arm and is the continuation of the axillary artery, begins at the inferior border of the teres major and ends in the cubital fossa opposite the neck of the radius where it divides into the radial and ulnar arteries, anterior to the triceps and brachialis

Front 242

What is the medial bicipital groove?

Back 242

where the pulsations of the brachial artery are palpable

Front 243

Where does the brachial artery accompany the median nerve?

Back 243

as it passes inferolaterally the brachial artery accompanies the median nerve which crosses anterior to the artery

Front 244

Describe the branches of the brachial artery.

Back 244

during its course through the arm the brachial artery gives rise to many unnamed muscular branches and the humeral nutrient artery (arises from its lateral aspect), main named branches are the deep artery of the arm and the superior and inferior ulnar collateral arteries (collaterals help form the arterial anastomoses of the elbow region

Front 245

Describe the ulnar artery.

Back 245

can be palpated on the lateral side of the FCU tendon where it lies anterior to the ulnar head, ulnar nerve on the medial side of the ulnar artery, brahcnes of the ulnar artery arising in the forearm participates in the periarticular anastomosis of the elbow and supply muscles of the medial and central forearm, the common flexor sheath and the ulnar and median nerves

Front 246

Describe the origin and course of the ulnar artery.

Back 246

1. origin-as larger terminal branch of brachial artery in cubital fossa
2. course in forearm-descends inferomedially and then directly inferiorly, deep to superficial (pronator teres and Palmaris longus) and intermediate (flexor digitorum superficialis) layers of flexor muscles to reach medial side of forearm, passes superficial to flexor retinaculum at writs in ulnar canal to enter hand

Front 247

Describe the origin and course of the common interosseus artery.

Back 247

1. origin-ulnar artery in cubital fossa, distal to bifurcation of brachial artery
2. course-passes laterally and deeply, terminating quickly by dividing into anterior and posterior interosseous arteries

Front 248

Describe the radial artery.

Back 248

pulsations can be felt throughout the forearm, lies on muscles until it reaches the distal part of forearm, here it lies on the anterior surfacec of the radius and is covered by only skin and fascia

Front 249

Describe the origin and course of the radial artery.

Back 249

1. origin-as smaller terminal branch of brachial artery in cubital fossa
2. course-runs inferolaterally under cover of brachioradialis, lies lateral to flexor carpi radialis tendon in distal forearm, winds around lateral aspect of radius and crosses floor of anatomical snuff box to pierce first dorsal interosseous muscle

Front 250

Describe the flexor carpi ulnaris (FCU).

Back 250

is the most medial of the superficial flexor muscles, flexes and adducts the hand at the wrist if acting alone, flexes wrist when it acts with FCR and adducts it when acting with the extensor carpi ulnaris, ulnar nerve runs between the humeral and ulnar head of the FCU, fully innervated by ulnar nerve, ulnar side

Front 251

How is the FCU tested?

Back 251

person puts the posterior aspect of the forearm and hand on a flat table and is then asked to flex the wrist against resistance while the examiner palpates the muscle and its tendon

Front 252

What is the proximal attachment, distal attachment, innervation and main action of the humeral head and ulnar head of the FCU?

Back 252

1. proximal attachment-humeral head (medial epicondyle of humerus), ulnar head (olecranon and posterior border (via aponeurosis)
2. distal attachment-pisiform, hook of hamate, 5th metacarpal
3. innervation-ulnar nerve (C7-C8)
4. main action-flexes and adducts hand (at wrist)

Front 253

Describe the flexor carpi radialis (FCR).

Back 253

long fusiform muscle locarted medial to the pronator teres, its fleshy belly is replaced by a long, flattened tendon that becomes cord-like as it approaches the wrist, produces flexion (with FCU) and abduction of the wrist (with extensor carpi radialis longus and brevis), when act alone does flexion and abduction simultaneously at the wrist, acts as a good guide to the radial artery which lies just lateral to it, radial side

Front 254

What is the proximal attachment, distal attachment, innervation and mian action of the FCR?

Back 254

1. proximal attachment0medial epicondyle of humerus
2. distal attachment-base of 2nd metacarpal
3. innervation-median nerve (C6, C7)
4. main action-flexes and abducts hand (at wrist)

Front 255

Describe the Palmaris longus.

Back 255

a small fusiform muscle, absent on one or both sides in 14% of people, has short bellyh and long, cord-like tendon, useful guid to the median nerve at the wrist, lies deep and slightly medial to this nerve before it passes deep to the flexor retinaculum, gives rise to dense CT palmar aponeurosis

Front 256

What is the proximal attachment, distal attachment, innervation and main action of the Palmaris longus?

Back 256

1. proximal attachment-medial epicondyle of humerus
2. distal attachment-distal half of flexor retinaculum and apex of palmar aponeurosis
3. innervation-median nerve (C7,C8)
4. main action-flexes hand (at wrist) and tenses palmar aponeurosis

Front 257

Describe the pronator teres.

Back 257

is the most lateral of the superficial forearm flexors, lateral border forms the medial boundary of the cubital fossa

Front 258

What is the proximal attachment, distal attachment, innervation and main action of the pronator teres?

Back 258

1. proximal attachment-ulnar head at coronoid process, humeral head at medial epicondyle of humerus
2. distal attachment-middle of convexity of lateral surface of radius
3. innervation-median nerve (C6, C7)
4. main action-pronates and flexes forearm (at elbow)

Front 259

Describe the flexor digitorum superficialis (FDS).

Back 259

largest superficial muscles in the forearm, forms intermediate layer between the superficial and deep groups of forearm muscles, median nerve and ulnar artery enter the forearm by passing between its humeroulnar and radial heads, gives rise to four tendons which pass deep to retinaculum through the carpal tunnel, many books place the FDS in an intermediate position because of its extensive origin

Front 260

What is the proximal attachment, distal attachment, innervation and main action of the FDS?

Back 260

1. proximal attachment-medial epicondyle (common flexor origin and coronoid process)
2. distal attachment-shafts (bodies) of middle phalanges of medial four fingers
3. innervation-median nerve (C7, C8, T1)
4. main action-flexes middle phalanges at proximal interphalangeal joints of middle four fingers, acting more strongly it also flexes proximal phalanges at metacarpophalangeal joints

Front 261

What muscles are in the superficial group of the anterior forearm?

Back 261

five muscles that arise from the medial epicondyle, all attached by common flexor tendon, include the pronator teres, FCR, Palmaris longus, FDS and FCU

Front 262

What muscles are in the deep group of the anterior forearm?

Back 262

three muscles arise form the interosseus membrane or radius and ulna and are considred to be the deep group, note the relationship of the brachial artery to the biceps tendon TAN, includes the FPL, FDP, and pronator quadratus

Front 263

Describe the flexor pollicis longus (FPL).

Back 263

long flexor of the thumb, lies lateral to the FDP where it clothes the anterior aspect of the radius distal to the attachment of the supinator, enveloped in its own synovial tendinous sheath of the flexor pollicis longus, only muscle that flexes the interphalangeal joint of the thumb

Front 264

What is the proximal attachment, distal attachment, innervation and main action of the FPL?

Back 264

1. proximal attachment-anterior surface of radius and adjacent interosseous membrane
2. distal attachment-base of distal phalanx of thumb
3. innervation-anterior interosseous nerve from median nerve (C8, T1)
4. main action-flexes phalanges of 1st digit (thumb)

Front 265

Describe the flexor digitorum profundus (FDP).

Back 265

only muscle that can flex the distal interphalangeal joints of the fingers, clotehs anterior aspect of the ulna, divides into four parts which end in four tendons that pass posterior to the FDS tendons and the flexor retinaculum within the common flexor sheath, can flex only the index finger independently thus the finger can be independently flexes at the proximal but not the distal interphalagneal joints, goes to distal phalanx, can act on the tip and MP joint

Front 266

What is the proximal attachment, distal attachment, innervation and main action of the FDP?

Back 266

1. proximal attachment-proximal three quarters of medial and anterior surfaces of ulna and interosseous membrane
2. distal attachment-medial part (bases of distal phalanges of 4th and 5th fingers), lateral part (bases of distal phalanges of 2nd and 3rd fingers)
3. innervation-medial part (ulnar nerve (C8, T1)), lateral part (anterior interosseous nerve from median nerve (C8, T1), main action
4. main action-medial part (flexes distal phalanges 4 and 5 at distal interphlangeal joints), lateral part (flexes distal phalanges 2 and 3 at distal interphalngeal joints)

Front 267

Describe the pronator quadratus.

Back 267

quadrangular and pronates forearm, deepest muscle in the anterior aspect of the forearm, clothes the distal fourth of the radius and ulna, only muscle to attach to only ulna at one end and only radius at the other end

Front 268

What is the proximal, distal attachment, innervation and main action of the pronator quadratus?

Back 268

1. proximal-distal quarter of anterior surface of ulna
2. distal-distal quarter of anterior surface of radius
3. innervation-anterior interosseus nerve from median nerve
4. main action-pronates forearm, deep fibers bind radius and ulna together

Front 269

Which muscles are pronators?

Back 269

pronator teres and pronator quadratus, cross from ulna to radius so when pull, pull the radius around

Front 270

Which muscles are wrist flexors?

Back 270

FCR, Palmaris longus and FCU, all muscles of the superficial group

Front 271

Which muscles are finger flexors?

Back 271

FDS (can act at the middle phalanx), FPL (goes to distal phalanx, mimics the FDP) and FDP (deepest finger flexor, passes right through to the distal phalanx, can’t act on the middle phalanx)

Front 272

Describe the association of the long tendons of the fingers.

Back 272

deep flexor tendon goes through a split in the superficial tendon, deep flexors go to the distal phalanx while superficial only go to medial phalanx

Front 273

Describe the innervation of the anterior compartment.

Back 273

all anterior compartment muscles are innervated by the median nerve except the FCU and the medial two heads of the FDP which get their innervation from the ulnar, reversed in the hand

Front 274

Describe the division of the anterior hand.

Back 274

can be divided into thenar (radial side, thumb side, thenar means thumb) and hypothenar (medial side, act on little finger) compartment muscles and lumbricals and interossei (both deep to palmar aponeurosis), note there are no intrinsic hand muscles in the dorsum of the hand

Front 275

Describe the muscles in the superficial hand.

Back 275

there are three thenar muscles and three hypothenar muscles that can be seen and lateral and medial to the palmar aponeuroses which covers the other intrinsic hand muscles, are called OAF muscles (opponens, abductor, flexors), same for both muscles

Front 276

What are the three thenar muscles?

Back 276

opponens pollicis, abductor pollicis brevis, flexor pollicis brevis, all three are innervated by the median nerve, the adductor pollicis is not a thenar compartment muscles but is a thumb muscle (so not innervated by median nerve, actually ulnar nerve)

Front 277

Describe the opponens pollicis.

Back 277

lies deep to the APB and lateral to the FPB, opposes the thumb, flexes and rotates the 1st metacarpal medially

Front 278

What is the proximal attachment, distal attachment, innervation and main action of the opponens pollicis?

Back 278

1. proximal attachment-flexor retinaculum and tubercles of scaphoid and trapezium
2. distal attachment-lateral side of 1st metacarpal
3. innervation-recurrent branch of median nerve
4. main action-to oppose thumb, it draws 1st metacarpal medially to center of palm and rotates it medially

Front 279

Describe the abductor pollicis brevis (APB).

Back 279

short abductor of the thumb, forms the anterolateral part of the thenar eminence, also assits the opponens pollicis during early stages of opposition by rotating its proximal phalanx slightly medially

Front 280

What is the proximal, distal, innervation and main action of the APB?

Back 280

1. proximal-flexor retinaculum and tubercles of scaphoid and trapezium
2. distal-lateral side of base of proximal phalanx of thumb
3. innervation-recurrent branch of median nerve (C8, T1)
4. main action-abducts thumb, helps oppose it

Front 281

Describe the flexor pollicis brevis (FPB).

Back 281

short flexor of the thumb, medial to the APB, has two bellies that differ in their innervation, flexes the thumb at the carpometacarpal and metacarpophalangeal joints and aids in opposition of the thumb, attach to proximal phalanx of thumb and will flex the thumb of the MP joint

Front 282

What is the proximal, distal, innervation and main action of the FPB?

Back 282

1. proximal-flexor retinaculum and tubercles of scaphoid and trapezium
2. distal-lateral side of base of proximal phalanx of thumb
3. innervation-superficial head (recurrent branch of median nerve), deep head (deep branch of ulnar nerve)
4. main action-flexes thumb, adducts thumb toward lateral border of palm

Front 283

describe the adductor pollicis.

Back 283

deeply placed, fan shaped adductor of the thumb, located in the adductor compartment of the hand, adducts the thumb, moving the thumb to the palm of the hand thereby giving power to the grip

Front 284

What is the proximal, distal, innervation and main action of the adductor pollicis?

Back 284

1. proximal-oblique head (bases of 2nd and 3rd metacarpals, capitate, adjacent carpals), transverse head (anterior surface of shaft of 3rd metacarpal
2. distal-medial side of base of proximal phalanx of thumb
3. innervation-deep branch of ulnar nerve
4. main action-adducts thumb toward lateral border of palm

Front 285

What are the three hypothenar muscles?

Back 285

opponens digiti minimi (deepest), abductor digiti minimi (most medial), flexor digiti minim (brevis), innervated by the ulnar nerve, produce the hypothenar eminence on the medial side of the palm and move the little finger

Front 286

Describe the opponens digiti minimi.

Back 286

lies deep to the abductor and flexor muscles of the 5th finger, draws 5th metacarpal anteriorly and rotates it laterally thereby deepening the hollow of the palm and bringing the 5th finger into opposition with the thumb, is exclusively at the carpometacarpal joint

Front 287

What is the proximal, distal, innervation and main action of the opponens digiti minimi?

Back 287

1. proximal-hook of hamate and flexor retinaculum
2. distal-medial border of 5th metacarpal
3. innervation-deep branch of ulnar nerve
4. main action-draws 5th metacarpal anterior and rotates it, bringing 5th finger into opposition with thumb

Front 288

Describe the abductor digiti minimi.

Back 288

most superficial of the three hypothenar muscles, abducts the 5th finger and helps flex its proximal phalanx

Front 289

What is the proximal, distal, innervationa nd main action of the abductor digiti minimi?

Back 289

1. proximal-pisiform
2. distal-medial side of base of proximal phalanx of 5th finger
3. innervation-deep branch of ulnar nerve
4. main action-abducts 5th finger, assists in flexion of its proximal phalanx

Front 290

Describe the flexor digiti minimi brevis.

Back 290

variable in size, lies lateral to the abductor digiti minimi, flexes the proximal phalanx of the 5th finger at the metacarpophalangeal joint

Front 291

What is the proximal, distal, innervation and main action of the flexor digiti minimi brevis?

Back 291

1. proximal-hook of hamate and flexor retinaculum
2. distal-medial side of base of proximal phalanx of 5th finger
3. innervation-deep branch of ulnar nerve
4. main action-flexes proximal phalanx of 5th finger

Front 292

What is Dupuytren’s contracture?

Back 292

a disease of the palmar fascia and aponeurosis resulting in thickening and shortening of fibrous band on the palmar surface of the hand and fingers, fibrous degeneration of the longitudinal bands of the palmar aponeurosis on the medial side of the hand pulls the 4th and 5th into partial flexion, freq. bilateral, hereditary predisposition, first manifests as nodular thickenings that adhere to skin

Front 293

What is the carpal tunnel?

Back 293

passageway deep to the flexor retinaculum and finally into the hand, is between the tubercles of the scaphoid and trapezoid bones on the lateral side and the pisiform and hook of the hamate on the medial side, 9 flexor tendons of the FDS (4), FDP (4) and FPL (1) and the median nerve pass through it, ulnar artery and nerve DO NOT pass through the tunnel, damage in the tunnel effects the thenar compartment muscles causing de-rotation of the thumb and an ape hand

Front 294

What does the median nerve in the hand supply?

Back 294

distal to the carpal tunnel, the median nerve supplies two and a half thenar muscles and the 1st and 2nd lumbricals, also sends sensory fibers to the skin on the entire palmar surface the sides of the first three digits, the lateral half of the 4th digit and the dorsum of the distal halves of these digits

Front 295

Describe the synovial sheets of the hand.

Back 295

all contents of the carpal tunnel are covered by a synovial tendon sheath, the little finger synovial sheaths is continuous with the ulnar bursa, the synovial sheath of the thumb is continuous with the radial bursa

Front 296

Describe carpal tunnel syndrome.

Back 296

results from any lesion that significantly reduces the size of the carpal tunnel or INC the size of some of the nine structures that pass through it, may lead to paresthesia (tingling), hypoesthesia (diminished sensation) or anesthesia (absence of sensation), progressive loss of coordination and strength in the thumb may occur if the cause of compression is not alleviated, individuals with carpal tunnel syndrome are unable to oppose the thumb and have difficulty buttoning shirt

Front 297

what is carpal tunnel release?

Back 297

done to relieve the compression and resulting symptoms, is partial or complete surgical division of the flexor retinaculum, incision is made toward the medial side of the wrist and flexor retinaculum to avoid possible injury to the recurrent branch of the median nerve

Front 298

Describe the lumbricals.

Back 298

originate from the flexor digitorum profundus tendons, insert in the extensor hoods, innervated by the median and ulnar nerves, 4 of them, flex the fingers at the metacarpophlangeal joints and extend the interphalangeal joints, arise from the deep tendon, attach to extensor hood, pass anterior to the axis for flexion and extension at MP joint

Front 299

What is the proximal, distal, innervation and main action of the lumbricals?

Back 299

1. proximal-1st and 2nd (lateral two tendons of flexor digitorum profundus), 3rd and 4th (medial three tendons of flexor digitorum profundus (as bipennate muscles)
2. distal-lateral sides of extensor expansions of 2nd-5th fingers
3. innervation-1st and 2nd (median nerve), 3rd and 4th (deep branch of ulnar nerve)
4. main action-flex metacarpophalangeal joints, extend interphalangeal joints of 2nd-5th fingers

Front 300

Describe the interossei muscles.

Back 300

4 dorsal (1-4) interosseous muscles (abductors) are located between the metacarpals, 3 palmar interosseous muscles (adductors) are on the palmar surfaces of the metacarpals in the interossei compartment of the hand (DAB-dorsal abduct and PAD-palmar adduct), all anterior compartment muscles, innervated by ulnar nerve

Front 301

What movements do the interossei and lumbricals allow for when functioning together?

Back 301

produce flexion at the metacarpophalangeal joints and extension of the interphalangeal joints (Z-movement), opposite of claw hand

Front 302

What are the proximal, distal attachments, innervation and main action of the dorsal interossei?

Back 302

1. proximal-adjacent sides of two metacarpals (as bipennate muscles)
2. distal-bases of proximal phalanges; extensor expansions of 2nd-4th finger
3. innervation-deep branch of ulnar nerve
4. main action-abduct 2nd-4th fingers from axial line, act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints

Front 303

what are the proximal, distal, innervation and main action of the palmar interossei?

Back 303

1. proximal-palmar surfaces of 2nd, 4th, and 5th metacarpals (as unipennate muscles)
2. distal-bases of proximal phalanges, extensor expansions of 2nd, 4th and 5th fingers
3. innervation-deep branch of ulnar nerve
4. main action-adduct 2nd, 4th, and 5th fingers toward axial line, assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints, extensor expansions of 2nd-4th fingers

Front 304

Where can the different tendon shetahs rupture and become infected?

Back 304

tendon sheaths of 2, 3, and 4 can become infected and rupture into the thenar (2) or midpalmar (3+4) space, tendon sheaths of 1 and 5 can become infected and rupture into the forearm

Front 305

What is the extensor hood?

Back 305

lumbrical and interosseous muscles insert into the extensor hood, when they pull on the hood cause transfer of force to hood causing extension at the distal and middle phalanx and flexion at the proximal phalanx

Front 306

What is the midpalmar space

Back 306

not really a space, wehre infection from rupture of tendon sheath can go, seen under 3-5

Front 307

What is the thenar space

Back 307

under 1-2 finger space, get inflammation from digit two into thenar space

Front 308

Describe the innervation of the intrinsic hand muscles.

Back 308

all the intrinsic muscles of the hand are innervated by the ulnar nerve except the thenar compartment muscles (three) and the lumbricals to the functional midline on the radial side (median)

Front 309

Describe the innervation of the radial nerve.

Back 309

posterior arm and forearm, motor innervation to the all muscles in the posterior compartment, gives cutaneous innervation to 3.5 digits on the posterior surface

Front 310

What nerve does a mid humeral shaft fracture injure?

Back 310

radial nerve

Front 311

Describe the innervation of the ulnar nerve.

Back 311

gives motor innervation to 1.5 muscles of the forearm (flexor carpi ulnaris and half of flexor digitorum profundus), all muscles of the hand except the thenar compartment and half the lumbricals, and cutaneous innervation to 1.5 digits

Front 312

What nerve does a fracture of the medial epicondyle damage?

Back 312

ulnar nerve

Front 313

Describe ulnar nerve palsy.

Back 313

most significant feature is the loss of innervation to the interossei muscles resulting in hyperextension at the MP joints, this hyperextension cause a concomitant flexion of the fingers due to the tethering pull of the FDS and FDP, this pull isn’t as severe in digits 2 and 3 because those two lumbricals are still working, leads to claw hand

Front 314

Describe claw hand.

Back 314

person has difficulty making a fist because in the absence of opposition, the metacarpophalangeal joints become hyperextended and he or she cannot flex the 4th and 5th fingers at ht edistal interphalangeal joints when trying to make a fist, cannot extend the interphalangeal joints when trying to straighten fingers, results from atrophy of the itnerosseous muscles of the hand, claw is produced by the unopposed action of the extensors and the flexor digitorum profundus

Front 315

Describe the innervation of the median nerve.

Back 315

motor innervation to the muscles of the forearm except the FCU and half of the FDP, 2 lateral OAF muscles, 2 lumbricals, and thenar compartment, cutaneous innervation to 3.5 digits

Front 316

Where can the median nerve be damaged?

Back 316

there are two significant places to damage the median nerve, at the elbow and the wrist, resulting in slightly different pathologies, if damage median nerve lose all flexion to pip and dip of 2+3 but not complete for 4+5, also get derotated thumb

Front 317

What is the origin, course and distribution of the median nerve in the hand?

Back 317

1. origin-arises by two roots, one from lateral cord and one from medial cord
2. course-becomes superifical proximal to wrist, passes deep to flexor retinaculum as it passes through carpal tunnel to hand
3. distrubtion-thenar muscles (except adductor pollicis and deep head of FPB) and lateral lumbricals (for digits 2 and 3), provides sensation to skin of palmar and distal dorsal aspects of lateral (radial) 3.5 digits and adjacent palm

Front 318

What is the origin, course and distribution of the ulnar nerve in the hand?

Back 318

1. origin-terminal branch of medial cord of brachial plexus
2. course-becomes superficial in distal forearm, passing superficial to flexor retinuaculum to enter hand
3. distribution-the majority of intrinsic muscles of hand, provides sensation to skin of palmar and distal dorsal aspects of medial 1.5 digits and adjacent palm

Front 319

Describe the origin of the posterior muscles of the forearm.

Back 319

most posterior forearm muscles arise form the common extensor tendon off the lateral epicondyle or the supracondylar ridge, the exceptions are the three thumb muscles, the extensor indices and the supinator (from radius, ulna or interosseous membrane)

Front 320

For the posterior/posterior forearm muscles, what is the rule of three?

Back 320

all posterior muscles are innervated by the radial nerve, there are three muscles to the thumb, fingers, wrist and three that don’t cross the wrist joint

Front 321

Describe the metacarpophalangeal (MP) joints.

Back 321

are the condyloid type of synovial joint that permit movement in two planes (flexion-extension and adduction-abduction), biaxial (MP at thumb is limited to flexion-extension)

Front 322

Describe the interphalangeal (IP) joints.

Back 322

are the hinge type of synovial joint and permit flexion and extension only, there are distal (DIP, between medial phalanx and distal phalanx) and proximal (PIP, between proximal and medial phalanx) types, comes from palmar side

Front 323

Describe the movement of these joints.

Back 323

muscle that works on these joints pull on all of the joints that is why it is difficult to move only IP joints, also need to know what is happening at the dorsum

Front 324

What are the articulations of the MP and PIP and DIP joints?

Back 324

heads of metacarpals articulate with the bases of the proximal phalanges in the MP joints, and the heads of the phalanges articulate with the bases of more distally located phalanges in the IP joints

Front 325

Describe the joint capsule of the metacarpophalangeal and interphalangeal joints.

Back 325

a joint capsule encloses each MC and IP joint with a synovial membrane lining a fibrous layer that is attached to the margins of each joint

Front 326

What do collateral ligaments at the MP and IP joints do?

Back 326

2 of them (medial and lateral) strengthens the fibrous layer of each MC and IP joint capsule

Front 327

What are the 2 parts of the collateral ligaments?

Back 327

1. denser cord-like parts that pass distally from the heads of the metacarpals and phalanges to the bases of the phalanges
2. thinner fan like parts that pass anteriorly to attach to thick, densely fibrous or fibrocartilaginous plates (palmar ligaments)

Front 328

What do the deep transverse metacarpal ligaments do?

Back 328

the palmar ligaments of the 2nd-5th MP joints are united by these, hold the heads of the metacarpals together, in addition the dorsal hood of each extensor apparatus attaches anteriorly to the sides of the palamr plates of the MP joints

Front 329

what movements are allowed at the MP and IP joints?

Back 329

flexion-extension, abduction-adduction and circumduction of the 2nd-5th digits occurs at the 2nd-5th MP joints, movement at the MP joint of the thumb is limited to flexion-extension, only flexion and extension occur at the IP joints

Front 330

What is the blood supply to the metacarpal and interphalangeal joints.

Back 330

deep digital arteries that arise form the superficial palmar arches supply the MC and IP joints

Front 331

What is the innervation of the MP and IP joints?

Back 331

digital nerves arising from the ulnar and median nerves supply the MC and Ip joints

Front 332

Describe the extensor expansion (hood).

Back 332

is a long extensor tendon (central band to base of middle phalanx), also a lateral band to distal phalanx, has a couple of muscles on the flexor (palmar) side that attaches to the hood, have an activity on that hood, when pull on interossei and lumbricals together get extension of IP joints and flexion of MP joints, the line of pull relative to the axis of this joint is palmar (anterior) to line of pull

Front 333

What is needed to make a tight fist?

Back 333

to make a tight fist, one needs to flex the MP joints, the FDP flexes the distal interphalangeal joint; the FDS flexes the proximal one

Front 334

Describe pathology of extensor hood.

Back 334

if jam finger into something when extended can pull distal band off the distal phalanx, can no longer get complete extension of the phalanx, extensor hood can play a role of how the finger looks after damage

Front 335

Describe the anatomical snuff box.

Back 335

APL and EPB bound it anteriorly, EPL bounds it posteriorly, visible when the thumb is fully extended, this draws the tendons up and produces a triangular hollow between them, axis of wrist is right between the snuff box, can’t get a pulse here from the radial artery, subQ branches of radial nerve pass through here

Front 336

What muscles/tendons make up the anatomical snuffbox?

Back 336

abductor pollicis longus (APL, adjacent to the EPB), extensor pollicis brevis (EPB) and extensor pollicis longus (EPL, most dorsal)

Front 337

What are the contents of the anatomical snuffbox?

Back 337

radial artery (in floor), base of 1st metacarpal (palpated distally), styloid process of radius (palpated proximally), crossed by dorsal digital branches of radial nerve, scaphoid and trapezium (felt in the floor between the radial styloid and 1st metacarpal

Front 338

Describe the APL.

Back 338

long, fusiform belly that lies distal to supinator and related to extensor pollicis brevis, tendon passes deep to the extensor retinaculum with the tendon of the EPB in the common synovial tendinous sheath of the APL and EPB, goes to the base of the metacarpal, performs abduction of thumb, pass anterior to transverse axis of carpal joint (where it performs flexion at the joint)

Front 339

What is the proximal, distal, innervation and main action of the APL?

Back 339

1. proximal-posterior surface of proximal halves of ulna, radius and interosseous membrane
2. distal-base of 1st metacarpal
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-abducts thumb and extends it at carpometacarpal joint

Front 340

describe the EPB.

Back 340

is the fusiform short extensor of the thumb, lies distal to the APL and is partly covered by it, tendon lies parallel and immediately medial to that of the APL but extends farther, reaching the base of the proximal phalanx, helps extend the 1st metacarpal and extend and abduct the hand, when thumb is fully extended can see snuff box on radial aspect of wrist, performs abduction of thumb, pass anterior to transverse axis of carpal joint (where it performs flexion at the joint)

Front 341

What is the proximal, distal, innervation and main action of the EPB?

Back 341

1. proximal-posterior surface of distal third of radius and interosseous membrane
2. distal-dorsal aspect of base of proximal phalanx of thumb
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends proximal phalanx of thumb at metacarpophalangeal joint, extends carpometacarpal joint

Front 342

Describe the EPL.

Back 342

larger and longer than the EPB, tendon passes under the extensor retinaculum in its own tunnel within the tendinous sheath of the EPL medial to the dorsal tubercle of the radius, uses tubercle as a pully to change its line of pull as it proceeds to the base of the distal phalanx forming snuff box, also adducts the extended thumb and rotates it laterally, goes to distal phalanx, passes through all three joints relative to the thumb

Front 343

What is the proximal, distal, innervation and main action of the EPL?

Back 343

1. proximal-posterior surface of middle third of ulna and interosseous membrane
2. distal-dorsal aspect of base of distal phalanx of thumb
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends distal phalanx of thumb at IP joint, extends MP and carpometacarpal joints

Front 344

What is the purpose of the extensor retinaculum?

Back 344

wide band in posterior compartment that holds the tendons of the muscles to the wrist/hand down, tendons passing through the compartments must be protected from wear by a synovial tendon sheath, all tendons going to the wrist are held down by the extensor retinaculum, prevents bowstringing of the tendons when the hand is extended at the wrist joint

Front 345

What is the purpose of the flexor retinuaculum?

Back 345

in the anterior compartment, forms the carpal tunnel

Front 346

What are the synovial tendon sheaths?

Back 346

as the tendons pass over the dorsum of the wrist they are provided with these, reduce friction for the extensor tendons as they traverse the osseofibrous tunnels formed by the attachment of the extensor retinaculum to the distal radius and ulna, blue sheets, if not present would quickly wear the tendons out

Front 347

What are the three posterior forearm muscles that act on the digitis?

Back 347

extensor digitorum, extensor digit minimi (EDM), extensor indicis

Front 348

Describe the extensor digitorum.

Back 348

is the principal extensor of the medial four fingers, occupies much of the posterior surface of the forearm, its four tendons (one to each finger) join the tendon of the extensor indicis, four tendons flatten to form the extensor expansions, tendon to 5th digit is coming off from combo from 4th finger

Front 349

What is the proximal, distal, innervation and main action of the extensor digitorum?

Back 349

1. proximal-lateral epicondyle of humerus (common extensor origin)
2. distal-extensor expansions of medial four fingers
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends medial four fingers primarily by MP joint, secondarily at IP joints

Front 350

Describe the EDM.

Back 350

fusiform slip of muscle, partially detached part of the extensor digitorum, tendon runs through a separate compartment of the extensor retinaculum then divides into two slips (lateral is jointed to the tendon fo the extensor digitorum), contributes to extension of the hand, to little finger itself

Front 351

What is the proximal, distal, innervation and main action of the EDM?

Back 351

1. proximal-lateral epicondyle of humerus
2. distal-extensor expansion of 5th finger
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends 5th finger primarily at MP joint, secondarily at IP joint

Front 352

Describe the extensor indicis.

Back 352

narrow, elongated belly, lies medial to and alongside that of the EPL, confers independence to the index finger, may act alone or together with the extensor digitorum to extend the index finger at the PIP joint, also helps extend the hand, deep muscle not coming off the common extensor tendon

Front 353

What is the proximal, distal, innervation and main action of the extensor indicis?

Back 353

1. proximal-posterior surface of distal third of ulna and interosseous membrane
2. distal-extensor expansion of 2nd finger
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends 2nd finger (enabling independent extension), helps extend hand at wrist

Front 354

What muscles act on the wrist in the posterior forearm muscles?

Back 354

extensor carpi radialis longus (ECRL), brevis (ECRB), and extensor carpi ulnaris (ECU), do not attach to the carpals, go out and attach at the metacarpals, 2nd, 3rd, and 5th

Front 355

Describe the ECRL.

Back 355

partly overlapped by the brachioradialis with which it often blends, passes distally posterior to brachioradialis, tendon is crossed by the APB and EPB, indispensable when clenching the fist, adduct when working with the FCR

Front 356

What is the proximal, distal, innervation and main action of the ECRL?

Back 356

1. proximal-lateral supraepicondylar ridge of humerus
2. distal-dorsal aspect of base of 2nd metacarpal
3. innervation-radial nerve
4. main action-extend and abduct hand at the wrist joint, ECRL active during fist clenching

Front 357

Describe the ECRB.

Back 357

arises distally in the limb, attaches adjeacent to the ECRL in the hand, covered by the ECRL distally, passes under the extensor retinaculum, acts with the ECRL synergistically (important in steadying the wrist during tight flexion of the medial four fingers, clenching)

Front 358

What is the proximal, distal, innervation and main action of the ECRB?

Back 358

1. proximal-lateral epicondyle of humerus
2. distal-dorsal aspect of base of 3rd metacarpal
3. innervation-deep branch of radial nerve
4. main action-extend and abduct hand at the wrist joint

Front 359

Describe the ECU.

Back 359

located on medial border of forearm, has two heads (humeral from common extensor tendon and ulnar from a common aponeurosis), extends and adducts hand, like the ECRL it is indispensable when clenching the fist

Front 360

what is the proximal, distal, innervation and main action of the ECU?

Back 360

1. proximal-lateral epicondyle of humerus, posterior border of ulna via a shared aponeurosis
2. distal-dorsal aspect of base of 5th metacarpal
3. innervation-posterior interosseous nerve, continuation of deep branch of radial nerve
4. main action-extends and adducts hand at wrist joint (also active during fist clenching)

Front 361

Which posterior forearm muscles don’t cross the wrist?

Back 361

brachioradialis, anconeus, supinator

Front 362

Describe the brachioradialis.

Back 362

superficial on the anterolateral surface of the forearm, forms lateral border of the cubital fossa, posterior muscle that has rotated to the anterior aspect of the huemrus and thus flexes the forearm at the elbow, overlies the radial nerve and artery where they lie together on the supinator, pronator teres tendon, FDS and FPL, distal part covered by the APL and APB, posterior compartment innervation but it is a flexor, freq. a cause of tennis elbow

Front 363

What is the proximal, distal, innervation and main action of the brachioradialis?

Back 363

1. proximal-proximal 2/3 of superepicondylar ridge of humerus
2. distal-lateral surface of distal end of radius proximal to styloid process
3. innervation-radial nerve
4. main action-relatveily week flexion of forearm, maximal when forearm is in midpronated position

Front 364

Describe the aconeus.

Back 364

on the posterolateral aspect of the elbow, partially blended with the triceps, helps triceps extend the forearm and tenses of the capsule of the elbow joint, makes the rule work (never ask question about)

Front 365

What is the proximal, distal, innervation and main action of the aconeus?

Back 365

1. proximal-lateral epicondyle of humerus
2. distal-lateral surface of olecranon and superior part of posterior surface of ulna
3. innervation-radial nerve
4. main action-assists triceps in extending forearm, stabilizes elbow joint, may abduct ulna during pronation

Front 366

Describe the supinator.

Back 366

lies deep in the cubital fossa and forms its floor, envelops the neck and proximal part of the shaft of the radius, deep branch of the radial nerve passes between its muscle fibers (when it exits the muscle and joints the posterior interosseous artery it is referred to as the posterior interosseous nerve), prime mover for slow, unopposed supination, fairly deep muscle (biceps is also a powerful supinator)

Front 367

What are the proximal, distal, innervation and main action of the supinator?

Back 367

1. proximal-lateral epicondyle of humerus, radial collateral and anular ligaments, supinator fossa, crest of ulna
2. distal-lateral posterior and anterior surface of proximal third of radius
3. innervation-deep branch of radial nerve
4. main action-supinates forearm, rotates radius to turn palm anteriorly or superiorly (if elbow is flexed

Front 368

Describe the course of the radial nerve in the posterior arm.

Back 368

it splits into superficial and deep, deep inervates most of the muscles in the forearm, the superficial is basically a sensory nerve and ends in the hand as cutaneous branches to the fingers

Front 369

What is origin and course of the superficial branch of the radial nerve?

Back 369

1. origin-sensory terminal branch of radial nerve in cubital fossa
2. course-descends between pronator teres and brachioradialis, emerging from latter to arborize over anatomical snuff box and supply skin of dorsum lateral to axis of 4th finger

Front 370

What is the origin and course of the deep branch of radial nerve?

Back 370

1. origin-motor terminal branch of radial nerve, in cubital fossa
2. course-deep branch exits cubital fossa winding around neck of radius, penetrating and supplying supinator, emerges in posterior compartment of forearm as posterior interosseous, descends on membrane with artery of same name

Front 371

What is the origin and course of the posterior cutaneous nerves of the forearm?

Back 371

1. origin-radial nerve, as it traverses radial groove of posterior humerus
2. course-perforates lateral head of triceps, descends along lateral side of arm and posterior aspect of forearm to wrist

Front 372

What is the origin and course of the lateral cutaneous nerve of the forearm?

Back 372

1. origin-continuation of musculocutaneous nerve distal to muscular branches
2. course-emerges lateral to biceps brachii on brachialis, running initially with cephalic vein, descends along lateral border of forearm to wrist

Front 373

What is the origin and course of the medial cutaneous nerve of the forearm?

Back 373

1. origin-medial cord of brachial plexus, receiving C8 and T1 fibers
2. course-perforates deep fascia of arm with basilica vein proximal to cubital fossa, descends medial aspect of forearm in subQ tissue to wrist

Front 374

What happens in radial nerve damage?

Back 374

damage to the radial nerve will result in varying effects depending on the location, damage high in the arm will cause wrist drop, weak or absent wrist and digit extension and no extension at the elbow (because injury is proximal to the branches to the extensors), this will also have an effect on grip strength (because of wrist drop, can’t make tight fist), damage in the forearm will have an effect primarily on the wrist and digit extensors

Front 375

What happens in long-standing nerve damage?

Back 375

muscles that become atrophy also get infiltration from CT and CT can shorten and cause tethering and pull, muscles often become tighter and more pull on the joint against the working muscles

Front 376

What is compartment syndrome?

Back 376

trauma in the forearm can cause swelling which may be restricted by fascial compartments, this can cause elvated pressure in the compartment and subsequent damage to arteries and nerves, because muscle groups are contained by dense CT sheet and if get swelling (for whatever reason) pressure can go up really fast and really high, can shutoff blood flow and nerves

Front 377

What is the profunda brachii artery?

Back 377

branch of the brachial artery high up on the arm, travels with the radial nerve in the humerus in the spiral groove

Front 378

What is the origin and course of the radial recurrent artery?

Back 378

1. origin-lateral side of radial artery, just distal to brachial artery bifurcation
2. course-ascends between brachioradialis and brachialis, supplying both, then anastomoses with radial collateral artery (from deep brachial artery)

Front 379

What is the origin and course of the anterior ulnar recurrent artery?

Back 379

1. origin-ulnar artery just distal to elbow joint
2. course-passes superiorly between brachialis and pronator teres, supplying both, then anastomoses with inferior ulnar collateral artery anterior to medial epicondyle

Front 380

What is the origin and course of the posterior ulnar recurrent artery?

Back 380

1. origin-ulnar artery distal to anterior ulnar recurrent artery
2. course-passes superiorly, posterior to medial epicondyle and deep to tendon of flexor carpi ulnaris, then anasomoses with superior ulnar collateral artery

Front 381

What is the origin and course of the common interosseous artery?

Back 381

1. origin-ulnar artery in cubital fossa, distal to bifurcation of brachial artery
2. course-passes laterally and deeply, terminating quickly by dividing into anterior and posterior interosseous arteries, die out before cross wrist joint

Front 382

Review the arteries of the hand.

Back 382

collateral flow between both arches, most blood to digits from the superficial arch except the index finger, superficial arch from ulnar but has collateral with radial, deep palmar arch from radial and hooks around snuff box but has collateral with ulnar, superficial is primary supply of blood to fingers (through common digitals -> proper digitals -> dorsal digitals, on the palmar aspect)

Front 383

What is the blood supply to the thumb?

Back 383

princes pollicis

Front 384

What is the origin and course of the princeps pollicis?

Back 384

1. origin-radial artery as it turns into palm
2. course-descends on palmar aspect of 1st metacarpal, divides at base of proximal phalanx into two branches that run along sides of thumb

Front 385

What is the origin and course of the common palmar digitals?

Back 385

1. origin-superficial palmar arch
2. course-pass distally on lumbricals to webbing of fingers

Front 386

What is the origin and course of the proper palmar digitals?

Back 386

1. origin-common palmar digital arteries
2. course-run along sides of 2nd-5th fingers

Front 387

What happens in ulnar nerve palsy?

Back 387

most significant feature is the loss of innervation to the interossei muscles resulting in hyperextension at the MP joints, this hyperextension cause a concomitant flexion of the fingers due to the tethering pull of the FDS and FDP, this pull isn’t as severe in digits 2 and 3 because those two lumbricals are still working, leads to claw hand, more curling at 4 and 5, less at 2 and 3 (because 2 and 3 are innervated by the lumbricals as well (innervated by median nerve), counteracts some hyperextension)

Front 388

What happens in median nerve damage?

Back 388

depends on position, if high at forearm or in wrist, two sig. places to damage the median nerve (at the elbow and wrist) resulting in different pathologies

Front 389

What happens if injure median nerve high up in the forearm (at the elbow)?

Back 389

get hand of benediction (table blessing), lose all flexion to pip and dip of 2+3 but not complete for 4+5, also get de-rotated thumb lose innervation of thenar compartment, lose FDP and FDS, still have interosseous muscles

Front 390

What happens if there is median nerve damage at the wrist?

Back 390

when the median nerve is damaged at the wrist the only muscles involved are the thenar compartment muscles and the first two lumbricals on the radial side, lumbrical loss in this case causes minimal effect but the thenar loss results in a derotated thumb with severe wasting of the thenar compartment

Front 391

What two ligaments are important in the AC joint?

Back 391

1. coracoclavicular ligaments are the reason why the clavicle breaks where it does, without these ligaments, AC separations would be more frequent
2. coracoacromial ligament-forms roof of glenohumeral joint, helps stabilize the shoulder joint

Front 392

What movements are allowed at the elbow joint?

Back 392

flexion and extension

Front 393

What ligaments are present at the elbow joint?

Back 393

1. radial collateral ligament-prevents adduction of forearm, extends from the lateral epicondyle of the humerus and blends distally with the annular ligament of the radius
2. ulnar collateral ligament-prevents abduction of forearm, extends from the medial epicondyle of th ehumerus to the coronoid pcoress and olecranon of the ulna, consists of anterior, posterior and oblique band
3. annular ligament-surrounds radius of head, encircles and holds the head of the radius in the radial notch of the ulna, in young children the head of radius is not developed and can pull head out of annular ligament if pull arms

Front 394

Describe the distal-radial ulnar joint.

Back 394

there is a disk that separates the radius from ulna and ulna from carpals, not a good connection between ulna and carpals

Front 395

Where is the main wrist joint?

Back 395

between the radius and carpals (radiocarpal joint), involved the scaphoid and lunate

Front 396

What are the ligaments of the radiocarpal joint?

Back 396

1. radio-carpal ligament-(palmar), pass from the radius to the two rows of carpals, strong and directed so that the hand follows the radius during supination of the forearm
2. ulno-carpal ligament-(palmar)
3. carpo-metacarpal ligament-(palmar)

Front 397

What is the transverse metacarpal ligament?

Back 397

it stabilizes the hand in single metacarpal fractures, right between the heads of the metacarpals at the MP joint, get really tight when go into flexion