Anatomy Jelena - Upper Extremity

Front 1

Axillary Nerve Origin + Innervation

Back 1

-C5-C6, posterior cord

-Innervates the deltoid and the teres minor

Front 2

Spinal accessory nerve

Back 2

-Crosses the triangle within the layers of deep fascia investing the sternocleidomastoid and trapezius muscle

-Innervates trapezius

Front 3

Suprascapular nerve

Back 3

-C4, C5, C6

-Runs perpendicularly under clavicle close to acromion

-Innervates the infraspinatus (C5, C6) and supraspinatus (C4, C5, C6) muscles

Front 4

Rotator cuff

Back 4

SITS:

Supraspinatous

Infraspinatous

Teres Minor
Subscapularis

"Cuff" because one muscle on the front of scapula, one on top, and two on the back

They stabilize the glenohumeral joint, meaning they are close to the pivot point! Don't participate in abduction or adduction

Front 5

Triangle of auscultation

Back 5

Bordered by:

Inferior portion of Trapezius

Superior portion of Latissimus Dorsi

Medial border of the scapula

-Lies over the 7th rib and 6th and 7th intercostal spaces

-This is where breathing can be heard really well

Front 6

General info about brachial plexus

Back 6

-C5-C8 and T1, responsible for motor innervation of all muscles of the upper extremity except the trapezius and levator scapula

-Damage to the brachial plexus causes arm to lie medially

Front 7

Pectoralis Major Muscle

Back 7

Front 8

Pectoralis Minor Muscle

Back 8

Front 9

Subclavius Muscle

Back 9

Front 10

Serratus Anterior Muscle

Back 10

Front 11

Trapezius Muscle

Back 11

Front 12

Latissimus Dorsi

Back 12

Front 13

Levator Scapulae Muscle

Back 13

Front 14

Rhomboid Minor Muscle

Back 14

Front 15

Rhomboid Major Muscle

Back 15

Front 16

Deltoid Muscle

Back 16

(take off "adduction")

Front 17

Supraspinatus Muscle

Back 17

Front 18

Infraspinatus Muscle

Back 18

Front 19

Teres Minor Muscle

Back 19

Front 20

Teres Major Muscle

Back 20

Front 21

Subscapularis Muscle

Back 21

Front 22

Triangular Space

Back 22

(Slightly more medial than the quadrangular space)

Borders: Teres major inferiorly, triceps brachii (long head) laterally, Teres minor superiorly

Contents: Circumflex scapular artery

Front 23

Quadrangular Space

Back 23

Borders: Teres major inferiorly, humerus laterally, Teres minor superiorly, Triceps brachii (long head) medially

Contents: Axillary nerve, posterior humeral circumflex artery

(Slightly more lateral than the triangular space)

Front 24

Triangular Interval

Back 24

Borders: Teres major, Triceps brachii (long head), Humerus

Contents: Profunda brachii artery, Radial nerve

Front 25

Biceps Brachii Muscle

Back 25

Front 26

Brachialis Muscle

Back 26

Front 27

Coracobrachialis Muscle

Back 27

Front 28

Triceps Brachii Muscle

Back 28

Front 29

Musculocutaneous Nerve

Back 29

-Comes off of lateral cord of brachial plexus (C5-C7)

-Innervates coracobrachialis, biceps brachii, brachialis

Front 30

Medial Cutaneous Nerve of the Arm

Back 30

1. Comes from medial cord of brachial plexus
2. Cutaneous innervation to anteromedial skin of arm

Front 31

Brachial Artery ****skip for now

Back 31

1. Continuation of the axillary artery after it crosses the inferior border of the teres major muscle
2. Often forms an anastamosis with the posterior humeral circumflex artery
3. Upon termination, divides into middle collateral artery and radial collateral artery
4. Superior ulnar collateral artery
5. Inferior ulnar collateral artery
6. At elbow, divides into radial artery and ulnar artery

Front 32

Anterior Forearm Muscles (4-1-3)

Back 32

SUPERFICIAL LAYER

Pronator teres muscle

Flexor carpi radialis muscle

Palmaris longus muscle

Flexor carpi ulnaris muscle

INTERMEDIATE LAYER

Flexor digitorum superficialis muscle

DEEP LAYER

Flexor digitorum profundus muscle

Flexor pollicis longus muscle

Pronator quadratus muscle

Front 33

Posterior Forearm Muscles (6-3-3)

Back 33

SUPERFICIAL LAYER

Brachioradialis muscle

Extensor carpi radialis longus muscle

Extensor carpi radialis brevis muscle

Extensor digitorum muscle

Extensor digiti minimi muscle

Extensor carpi ulnaris muscle

DEEP LAYER

Anconus

Supinator muscle

Extensor indicis muscle

OUTCROPPING MUSCLES OF DEEP LAYER

Abductor pollicis longus muscle

Extensor pollicis longus muscle

Extensor pollicis brevis muscle

Front 34

Pronator Teres Muscle

Back 34

Anterior arm, superficial layer

Front 35

Flexor Carpi Radialis Muscle

Back 35

Anterior arm, superficial layer

Front 36

Palmaris Longus Muscle

Back 36

Anterior arm, superficial layer

Front 37

Flexor Carpi Ulinaris Muscle

Back 37

Anterior arm, superficial layer

Front 38

Flexor Digitorum Superficialis Muscle

Back 38

Anterior arm, intermediate layer

Front 39

Flexor Digitorum Profundus Muscle

Back 39

Anterior arm, deep layer

Front 40

Flexor Pollicis Longus Muscle

Back 40

Anterior arm, deep layer

Front 41

Pronator Quadratus Muscle

Back 41

Anterior arm, deep layer

Front 42

Brachioradialis Muscle

Back 42

Posterior arm, superficial layer

Front 43

Extensor Carpi Radialis Longus Muscle

Back 43

Posterior arm, superficial layer

Front 44

Extensor Carpi Radialis Brevis Muscle

Back 44

Posterior arm, superficial layer

Front 45

Extensor Digitorum Muscle

Back 45

Posterior arm, superficial layer

Front 46

Extensor Digiti Minimi Muscle

Back 46

Posterior arm, superficial layer

Front 47

Extensor Carpi Ulnaris Muscle

Back 47

Posterior arm, superficial layer

Front 48

Supinator Muscle

Back 48

Posterior arm, deep layer

Front 49

Extensor Indicis Muscle

Back 49

Posterior arm, deep layer

Front 50

Abductor Pollicis Longus Muscle

Back 50

Posterior arm, deep layer

Front 51

Extensor Pollicis Longus Muscle

Back 51

Posterior arm, deep layer

Front 52

Extensor Pollicis Brevis Muscle

Back 52

Posterior arm, deep layer

Front 53

Median Nerve Origin + Pathway

Back 53

-Comes from lateral (C5, C6, C7) and medial cord (C8, T1)

1. Travels through cubital fossa → passes under bicipital aponeurosis and between two heads of pronator teres muscle → enters anterior compartment of forearm
2. Travels between flexor digitorum superficialis and flexor digitorum profundus muscles
3. Before entering the flexor retinaculum via carpal tunnel, the main branch of median nerve gives off a palmar branch that enters the hand by passing over the flexor retinaculum

4. The rest of the median nerve is now called the anterior interosseus branch of median nerve

Front 54

Ulnar Nerve *****skip for now

Back 54

1. Runs posterior to medial epicondyle of humerus
2. Enters anterior compartment of forearm between the heads of the flexor carpi ulnaris muscle
3. Innervates the ulnar half of flexor digitorum profundus muscle and flexor carpi ulnaris muscle
4. Before crossing the wrist, it branches into a dorsal branch (cutaneous innervation to medial part of dorsal hand) and apalmar branch (cutaneous innervation to medial palm)
5. Enters hand through Guyon's canal, which is between the flexor tendons and the hook of hamate

Front 55

Path of Radial Nerve

Back 55

-Comes from posterior cord of brachial plexus (C5, C6, C7, T1)

-Enters radial groove of humerus along with profunda brachial artery, between the lateral and medial head of triceps

-Goes into cubital fossa by piercing intermuscular septum between brachialis and brachioradialis

-Passes anterior to lateral epicondyle of humerus, and divides into Superficial Branch and Deep Branch (which turns into Posterior Interosseus Nerve)

Front 56

Medial Cutaneous Nerve of the Forearm (Medial Antebrachial Cutaneous Nerve)

Back 56

1. Comes off the medial cord
2. Provides cutaneous innervation of medial part of forearm

Front 57

Long Thoracic Nerve

Back 57

-Arises from the C5, C6, and C6 roots

-Emerges from the middle scalene muscle and runs far down below the brachial plexus

-Supplies the serratus anterior

Front 58

Dorsal Scapular Nerve

Back 58

-Arises from C5 root and goes through the middle scalene muscle

-Supplies rhomboid minor and rhomboid major muscles

Front 59

5 Branches of the Posterior Cord of the Brachial Plexus

Back 59

1. Axillary nerve: goes around the neck of the humerus along with the humeral circumflex artery; supplies deltoid and teres minor

2./3. Subscapular nerves (upper/lower); supply subscapularis and teres major

4. Thoracodorsal nerve; supplies the latissimus dorsi

5. Radial nerve: Passes anterior to lateral epicondyle of humerus to innervate the posterior of the arm with some exceptions

Front 60

Lateral Cord of the Brachial Plexus

Back 60

1. Lateral pectoral nerve (C5-C7), which pairs with medial pectoral nerve to innervate the pectoralis major and pectoralis minor

2. Musculocutaneous nerve (C5-C7); innervates three upper arm muscles (coracobrachialis, biceps brachii, and brachialis)

Front 61

Medial Cord of the Brachial Plexus

Back 61

Gives rise to medial pectoral nerve, which pairs with lateral pectoral nerve to innervate the pectoralis major and pectoralis minor

Front 62

2 Pronator Muscles

2 Supinator Muscles

Back 62

Pronators:

1. Pronator Teres

2. Pronator Quadratus

Supinators:

1. Biceps brachii

2. Supinator

Front 63

Most common rotator cuff injury

Back 63

Falling with your arm out

First to get injured is usually the supraspinatous

Any of the tendons ripping can go through the joint capsule and tear the whole cuff

Front 64

Flexion of the arm (2 major muscles, 2 helpers)

Back 64

MAJOR

1. Deltoid (anterior chords)

2. Pectoralis major

HELPERS

-Engaged if you're flexing with a force ex when bowling

1. Coracobrachialis

2. Biceps brachii

-can only help if the insertion is more anterior than the arm (so if arm is coplanar, useless)

Front 65

Extension of the arm (4 major muscles, 2 helpers)

Back 65

MAJOR

1. Deltoid (posterior chords)

2. Pectoralis Major

3. Latissimus Dorsi

4. Teres Major

HELPERS

1. triceps (long head)

2. coracobrachialis, barely barely

Front 66

Abduction of the arm (2 major muscles)

Back 66

1. Deltoid (mostly lateral part/middle head, though anterior and posterior heads can help)

2. Supraspinatus, need it for first 15 degrees of movement

Front 67

Adduction of the arm (5 major muscles)

Back 67

1. Pectoralis major

2. Latissimus dorsi

3. Teres major

4. Coracobrachialis

5. Triceps (long head)

The latter two are useful when arm is fully abducted but almost useless when arm close to body

Front 68

Medial rotation of the arm (5 major muscles)

Back 68

1. Pectoralis major

2. Latissimus dorsi

3. Teres major

4. Subscapularis

5. Deltoid (anterior part)

Basically if origin is medial to humerus and insertion is somewhere on anteromedial side5tf

Front 69

The Lady Between Two Majors

Back 69

"The lady between two majors":
Teres major attaches to medial lip of groove.
Pectoralis major to lateral lip of groove.
Latissimus (Lady) is on floor of groove, between the 2 majors.

Front 70

Lateral Rotation (3 major muscles)

Back 70

1. Deltoid (posterior)

2. Infraspinatus

3. Teres minor

Front 71

Flexion of the Elbow (3 major muscles)

Back 71

1. Biceps brachii

2. Brachialis

3. Brachioradialis

Front 72

Which two nerves have to get destroyed to abolish flexion at the elbow?

Back 72

1. Musculocutaneous nerve (innervates biceps and brachialis)

2. Radial nerve (innervates brachioradialis)

Front 73

Extension of the Elbow (1 major muscle, 1 helper);

Which nerve would you have to knock out to compromise extension at the elbow?

Back 73

Major: triceps

Helper: anconeus

Radial Nerve, for ex via a midshaft humerus fracture

Front 74

Pronation of the forearm (2 major muscles); Which nerve would you have to knock out to compromise pronation?

Back 74

1. Pronator Teres

2. Pronator Quadratus

Median Nerve

Front 75

Supination of the forearm (2 major muscles);

Which nerves would you have to knock out to compromise supination?

Back 75

1. Supinator Muscle, innervated by Radial nerve

2. Biceps Brachii, innervated by Musculocutaneous Nerve

Front 76

Path of Axillary Nerve

Back 76

-Comes from posterior cord of brachial plexus (C5, C6)

-Passes through quadrangular space along with posterior circumflex humeral artery, to posterior aspect of arm; innervates deltoid and teres minor

-Winds around surgical neck of humerus

-Gives rise to Lateral Brachial Cutaneous Nerve

Front 77

Path of Musculocutaneous Nerve

Back 77

-Comes from lateral cord of brachial plexus (C5, C6, C7)

-Pierces and innervates coracobrachialis muscle
-Descends in between the biceps brachii and brachialis muscles + motor innervates
-Passes the elbow via cubital fossa, pierces deep fascia, and becomes the Lateral Antebrachial Cutaneous Nerve, which provides sensory innervation in the forearm

Front 78

Superficial Branch of Radial Nerve - Pathway and Innervation

Back 78

-Superficial radial nerve travels under brachioradialis muscle along with radial artery

-Enters anatomical snuffbox, and provides cutaneous innervation to dorsal thumb, index, and half of middle finger up until the distal phalanges (which are innervated by the median nerve

Front 79

Radial Nerve Origin + Innervations of Radial Nerve Proper

Back 79

-Posterior cord of Brachial Plexus, C5, C6, C7, T1

-Radial nerve proper innervates Brachioradialis, Anconeus, and Extensor Carpi Radialis Longus

Front 80

Innervations of Superficial Branch of Radial Nerve

Back 80

-Deep branch dives through two heads of supinator muscle + innervates it → becomes posterior interosseous nerve

→ innervates all of the muscles in the posterior compartment of the forearm
-gives off branches that provide cutaneous innervation to the posterior forearm distal to supinator

Front 81

Thenar Compartment of Hand (3)

Back 81

1. Abductor Pollicis Brevis

2. Flexor Pollicis Brevis

3. Opponens Pollicis Muscle

Front 82

Hypothenar Compartment of Hand (3)

Back 82

1. Abductor Digiti Minimi

2. Flexor Digiti Minimi

3. Opponens Digiti Minimi

Front 83

Abductor Pollicis Brevis Muscle

Back 83

Part of Thenar Compartment

Front 84

Flexor Pollicis Brevis Muscle

Back 84

Part of Thenar Compartment

Front 85

Opponens Pollicis Muscle

Back 85

Part of Thenar Compartment

Front 86

Abductor Digiti Minimi Muscle

Back 86

Part of Hypothenar Compartment

Front 87

Flexor Digiti Minimi Brevis Muscle

Back 87

Part of Hypothenar Compartment

Front 88

Opponens Digiti Minimi Muscle

Back 88

Part of Hypothenar Compartment

Front 89

Lumbricals

Back 89

4 of them

Front 90

Adductor Policis Muscle

Back 90

Front 91

Dorsal Interossei Muscles

Back 91

4 of them total, 2 for middle finger

Front 92

Palmar Interossei Muscles

Back 92

3 of them, middle finger doesn't need one

Front 93

Median Nerve Motor Innervation in the Hand

Back 93

1/2 LOAF 1/2

-1/2 lumbricles (2+3)

-opponens pollicis

-abductor pollicis brevis

-1/2 flexor pollicis brevis (superficial head)

Front 94

Ulnar Nerve Motor Innervation in the Hand (8)

Back 94

-1/2 lumbricles (4+5)

-opponens digiti minimi

-abductor digiti minimi

-flexor digiti minimi

-1/2 flexor pollicis brevis (deep head)

-all 4 palmar interossei

-all 4 dorsal interossei

-adductor pollicis

Front 95

Anterior Forearm Innervation + Exceptions

Back 95

-All the layers are innervated by the Median nerve except for Flexor Carpi Ulinaris and Flexor Digitorum Profundus (which is 1/2 and 1/2)

-These are innervated by the Ulnar nerve, which is sandwiched between them

Front 96

Cutaneous Innervation of the Hand

Back 96

-Palmar branch of Median Nerve: cutaneous innervation to 1/2 thenar, 2 1/2 fingers on the palmar side + their tips on the dorsal side

-Superficial Branch of Radial Nerve: 1/2 thenar, dorsal index + 1/2 middle

-Ulnar Nerve: 2 1/2 on dorsal ulnar side, 1 1/2 on palmar ulnar side

Front 97

Branches of the Median Nerve

Back 97

-Recurrent branch of median nerve (to thenar compartment)

-Anterior interosseus branch of median nerve does the deep layer of the forearm (1/2 Flexor Digitorum Profundus, Flexor Pollicis Longus, Pronator Quadratus)

Front 98

Order of the Superficial Layer of Anterior Forearm

Back 98

Pass Fail Pass Fail, in order from lateral to medial

Pronator Teres

Flexor Carpi Radialis

Palmaris Longus

Flexor Carpi Ulinaris

Front 99

Order of the Superficial Layer of Posterior Forearm

Back 99

From radial to ulnar:

1. Brachioradialis

2. Extensor Carpi Radialis Longus (to shorter finger)

3. Extensor Carpi Radialis Brevis (to longer finger)

4. Extensor Digitorum (4 of them)

5. Extensor Digiti Minimi

6. Extensor Carpi Ulinaris

Front 100

Order of the Deep Layer of Posterior Forearm

Back 100

From elbow to hand:

1. Anconeus

2. Supinator

3. Abductor Pollicis Longus

4. Extensor Pollicis Brevis

5. Extensor Pollicis Longus

6. Extensor Indicis

Front 101

Flexion of the Wrist (3 major) + which nerve(s) would need to get knocked out?

Back 101

1. Flexor Carpi Radialis (Median Nerve)

2. Flexor Carpi Ulinaris (Ulnar Nerve)

3. Palmaris Longus (Ulnar Nerve)

Front 102

Extension of the Wrist (3 major) + which nerve(s) would need to get knocked out?

Back 102

1. Extensor Carpi Radialis Longus

2. Extensor Carpi Radialis Brevis

3. Extensor Carpi Ulinaris

Radial nerve for all of them

Front 103

Radial Abduction of Wrist (3 major) + which nerve(s) would need to get knocked out?

Back 103

1. Flexor Carpi Radialis

2. Extensor Carpi Radialis Longus

3. Extensor Carpi Radialis Brevis

They all work simultaneously, so you would need to knock out both Median (for the Flexor Carpi Radialis) and Radial nerve (for the other two)

Front 104

Ulnar Abduction of Wrist (2 major) + which nerve(s) would need to get knocked out?

Back 104

1. Flexor Carpi Ulinaris

2. Extensor Carpi Ulinaris

Ulnar Nerve (for Flexor Carpi Ulinaris)

and

Median Nerve (for Extensor Carpi Ulinaris)

Front 105

Anconeus

Back 105

Posterior arm, deep layer

Front 106

Anatomical Snuffbox + Contents

Back 106

-Scaphoid carpal bone forms the floor

-Extensor Pollicis Brevis tendon forms the lateral/radial border

-Extensor Pollicis Longus tendon forms the medial/ulnar border

-Radial artery and dorsal cutaneous branch of radial nerve pass through it

Front 107

Carpal Tunnel + Contents

Back 107

-Formed by flexor retinaculum on top, carpal bones at the bottom

-Contents: median nerve and the tendons of flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum profundus

Front 108

Guyon's Canal + Contents

Back 108

-Formed by flexor retinaculum and transverse carpal ligament overlying the depression between the pisiform and hamate

-Contents: ulnar nerve + artery