Anatomy 1

Front 1

trapezius

Back 1

origin: superior nuchal line, external occipital protuberance, ligamentum nuchae, and spinous processes of CV7-TV12.
insertion: lateral third of clavicle, acromion process, spine of scapula; middle and lower fibers at medial end of spine of scapula.
action: upper fibers elevate shoulder, middle fibers retract shoulders, upper and lower together rotate the scapula.
innervation: accessory nerve (CN XI) and C3 and C4.
blood supply: transverse or superficial cervical arteries.

Front 2

latissimus dorsi

Back 2

origin: spinous processes of TV7-sacrum, crest of ilium, lower ribs, posterior lamella of thoracolumbar fascia.
insertion: lesser tubercular ridge and intertubercular sulcus of humerus.
action: extends, adducts, and medially rotates humerus.
innervation: thoracodorsal nerve.
blood supply: thoracodorsal vessels.

Front 3

levator scapulae

Back 3

origin: transverse processes of CV1-CV4.
insertion: vertebral border of scapula above spine.
action: elevates the scapula.
innervation: C3 - 4 of cervical plexus, dorsal scapular nerve.
blood supply: dorsal scapular vessels.

Front 4

rhomboideus major

Back 4

origin: spinous processes of CV7-TV4.
insertion: vertebral border of scapula below the spine.
action: retract shoulder
innervation: dorsal scapular nerve.
blood supply: dorsal scapular vessels.

Front 5

rhomboideus minor

Back 5

origin: lower part of ligamentum nuchae and spine of CV7.
insertion: vertebral border of scapula at the level of the spine.
action: retract the shoulders.
innervation: dorsal scapular nerve.
blood supply: dorsal scapular vessels.

Front 6

serratus posterior superior and inferior muscles

Back 6

origin: in the midline from spinous processes.
insertion: ribs.
action: inspiration (respiratory).
innervation: intercostal nerves.

Front 7

splenius capitis and cervicis muscles

Back 7

origin: ligamentum nuchae and spinous processes of CV7-TV6.
insertion: superior nuchal line, mastoid process (capitis), and transverse processes of CV2 or CV3 (cervicis).
action: together extend head and neck, individually turn head to same side.
innervation: dorsal primary rami.

Front 8

erector spinae muscles

Back 8

spinalis: along spine, one spinous process to another.
longissimus: in the middle.
iliocostalis: from ilium to ribs.
action: extensor of back
innervation: dorsal primary rami.

Front 9

transversospinal group of muscles

Back 9

from transverse processes to spinous processes?
seminspinalis: 6 segments.
multifidus: 3-5 segments.
rotator: 1-2 segments.
action: rotation of vertebral column to the opposite side.
innervation: dorsal primary rami.

Front 10

suboccipital triangle

Back 10

inferior oblique: origin at spine of CV2, insertion at transverse process of CV1.
superior oblique: origin at transverse process of CV1, insertion at occipital bone.
rectus capitis posterior major: origin at spine of CV2. insertion at occipital bone.
(also rectus capitis posterior minor muscle: origin at posterior tubercle of CV1, insertion at occipital bone.)
action: extend head, rotate it and atlas toward same side.
innervation: suboccipital nerve, dorsal/posterior ramus of C1.

Front 11

pectoralis major muscle

Back 11

origin: medial part of clavicle, sternum, costal cartilages of ribs 2-5, and upper rectus sheath.
insertion: greater tubercular crest of humerus.
action: adduction, medial rotation, and flexion of arm at shoulder joint.
innervation: medial and lateral pectoral nerve.
blood supply: thoracoacromial trunk, lateral thoracic artery, perforating intercostal branches, anterior perforating branches of internal thoracic artery.

Front 12

pectoralis minor muscle

Back 12

origin: ribs 2-4 or 3-5.
insertion: coracoid process of scapula.
action: protracts and depresses shoulder.
innervation: medial pectoral nerve.

Front 13

subclavious muscle

Back 13

origin: junction of first rib with its costal cartilage.
insertion: inferior surface of clavicle.
action: depresses clavicle.
innervation: upper trunk of the brachial plexus.

Front 14

external intercostals

Back 14

origin: lower border of superior rib.
insertion: upper border of inferior rib.
action: stabilizes ribs and aids in inspiration.

Front 15

internal intercostals

Back 15

origin: upper border of inferior rib.
insertion: lower border of superior rib.
action: aids in expiration.

Front 16

innermost intercostal muscle

Back 16

fibers of internal intercostal muscle serparated from it by intercostal nerve and vessels.

Front 17

sternocleidomastoid muscle

Back 17

origin: the manubrium and medial end of the clavicle.
insertion: the mastoid process.
action: contraction of one turns head to opposite side, contraction of both flexes neck.
innervation: accessory nerve (CNXI) and branches of C2 and C3.

Front 18

anterior scalene

Back 18

origin: anterior tubercle of transverse processes of CV3-CV6.
insertion: scalene tubercle of first rib between the grooves for subclavian vessels.
action: inspiration, act on vertebral column of neck.
innervation: C5-C7.

Front 19

middle scalene muscle

Back 19

origin: posterior tubercle of transverse processes of CV2-CV7.
insertion: superior surface of first rib posterior to brachial plexus and subclavian artery.
action: inspiration, acts on vertebral column of neck.
innervation: C3-C7.

Front 20

posterior scalene

Back 20

origin: posterior tubercle of transverse processes of CV5-CV7.
insertion: second rib.
action: inspiration, acts of vertebral column of neck.
innervation: C7-C8.

Front 21

omohyoid muscle

Back 21

origin: upper border of scapula.
insertion: lower border of hyoid bone.
innervation: ansa cervicalis.
composed of inferior belly and superior belly.

Front 22

subscapularis muscle

Back 22

origin: subscapular fossa of scapula.
insertion: lesser tubercle of humerus.
action: medially rotates arm. (too high on humerus to adduct).
innervation: upper and lower subscapular nerves.
blood supply: subscapular vessels.

Front 23

teres major muscle

Back 23

origin: inferior angle and adjacent axillary border of scapula.
insertion: lesser tubercular ridge of humerus.
action: adducts and medially rotates arm.
innervation: lower subscapular nerve.
blood supply: subscapular vessels.

Front 24

serratus anterior muscle

Back 24

origin: upper eight ribs.
insertion: vertebral border of scapula.
action: prevents retraction of scapula and shoulder (holds scapula against rib cage), lower fiber assist trapezius in rotating scapula or shoulder.
loss of nerve supply (long thoracic from C5-C7) results in winged scapula.

Front 25

supraspinatus muscle

Back 25

origin: supraspinatus fossa of scapula.
insertion: greater tubercle.
action: abducts arm and assists deltoid in its full movement.
innervation: suprascapular nerve.

Front 26

infraspinatus muscle

Back 26

origin: infraspinatus fossa of scapula.
insertion: greater tubercle.
action: chief lateral rotator of arm.
innervation: suprascapular nerve.

Front 27

teres minor muscle

Back 27

origin: lateral border of scapula.
insertion: greater tubercle.
action: laterally rotates arm.
innervation: axillary nerve.

Front 28

subscapularis

Back 28

origin: costal surface of scapula.
insertion: lesser tubercle.
action: medially rotates arm.
innervation: upper and lower subscapular nerves.

Front 29

coracobrachialis muscle

Back 29

origin: coracoid process.
insertion: half-way down medial aspect of humerus.
action: adducts arm.
innervation: musculocutaneous nerve.

Front 30

biceps brachii muscle

Back 30

origin: supraglenoid tubercle (long head) and coracoid process (short head).
insertion: radial tuberosity (some fibers form bicipital aponeurosis).
action: flexes shoulder, flexes forearm at elbow and supinates forearm.
innervation: musculocutaneous nerve.

Front 31

brachialis muscle

Back 31

origin: lower anterior half of humerus.
insertion: ulnar tuberosity.
action: flexes forearm at elbow.
innervation: musculocutaneous nerve.

Front 32

triceps brachii muscle

Back 32

origin: infraglenoid tubercle of scapula (long head), upper half of humerus (lateral head), lower half of humerus (medial head).
insertion: olecranon process.
action: extends forearm at elbow, extends shoulder.
innervation: radial nerve.

Front 33

brachioradialis muscle

Back 33

origin: lateral supracondylar line of humerus.
insertion: near styloid process of radius.
action: flexes forearm at elbow.
innervation: radial nerve.

Front 34

pronator teres muscle

Back 34

origin: medial epicondyle of humerus (superficial head), medial side of coronoid process of ulna (deep head).
insertion: midpoint of radial shaft.
action: pronates forearm.
innervation: median nerve.

Front 35

flexor carpi radialis muscle

Back 35

origin: medial epicondyle of humerus.
insertion: goes through flexor retinaculum to 2nd and 3rd metacarpals.
action: flexes and abducts hand at wrist.
innervation: median nerve.

Front 36

flexor carpi radialis muscle

Back 36

origin: medial epicondyle of humerus.
insertion: goes through flexor retinaculum to 2nd and 3rd metacarpals.
action: flexes and abducts hand at wrist.
innervation: median nerve.

Front 37

palmaris longus muscle

Back 37

origin: medial epicondyle of humerus.
insertion: flexor retinaculum and palmar aponeurosis.
action: flexes hand at wrist and tenses palmar aponeurosis.
innervation: median nerve.

Front 38

flexor carpi ulnaris muscle:

Back 38

origin: medial epicondyle of humerus and ulna.
insertion: pisiform (ligament connections to hook of hamate and base of 5th metacarpal).
action: flexes and adducts hand at wrist.
innervation: ulnar nerve.

Front 39

flexor digitorum superficialis muscle

Back 39

origin: medial epicondyle of humerus, mid shaft of radius, and coronoid process of ulna.
insertion: middle phalanges of four fingers (tendons split) (passes through carpal tunnel in stacked configuration - III and IV more superficial).
action: flexes middle phalanges and continues to flex proximal phalanges, hand at wrist, and forarm at elbow.
innervation: median nerve.

Front 40

flexor pollicis longus muscle

Back 40

origin: anterior surface of radius and interosseus membrane.
insertion: distal phalanx of thumb.
action: flexes thumb.
innervation: anterior interosseous branch of median nerve.

Front 41

flexor digitorum profundus muscle

Back 41

origin: posterior and medial surface of ulna.
insertion: distal phalanges of four fingers (go through carpal tunnel in planar configuration).
action: flexes phalanges, metacarpals, and wrist.
innervation: ulnar and median nerves.

Front 42

pronator quadratus muscle

Back 42

origin: ulna.
insertion: radius.
action: pronates hand.
innervation: anterior interosseus branch of median nerve.

Front 43

abductor pollicis brevis muscle

Back 43

origin: lateral end of flexor retinaculum.
insertion: lateral side of base of proximal phalanx of thumb.
action: abducts thumb.
innervation: recurrent branch of median nerve.
blood supply: superficial palmar branch of radial artery.

Front 44

opponens pollicis muscle

Back 44

origin: lateral end of flexor retinaculum.
insertion: along shaft of first metacarpal.
action: opposition (adduction) of thumb.
innervation: recurrent branch of median nerve.
blood supply: superficial palmar branch of radial artery.

Front 45

flexor pollicis brevis muscle

Back 45

origin: lateral end of flexor retinaculum.
insertion: on lateral side of base of proximal phalanx.
action: flexes thumb.
innervation: recurrent branch of median nerve.
blood supply: superficial palmar branch of radial artery.

Front 46

abductor digiti minimi muscle

Back 46

origin: medial end of flexor retinaculum.
insertion: medial side of base of proximal phalanx of little finger.
action: abducts little finger.
innervation: deep branch of ulnar nerve.
blood supply: superficial and deep branches of ulnar artery.

Front 47

opponens digiti minimi muscle

Back 47

origin: medial end of flexor retinaculum.
insertion: medial side of entire fifth metacarpal.
action: opposition (adduction) of little finger.
innervation: deep branch of ulnar nerve.
blood supply: superficial and deep branches of ulnar artery.

Front 48

flexor digiti minimi muscle

Back 48

origin: medial end of flexor retinaculum.
insertion: medial side on entire fifth metacarpal.
action: flexes little finger.
innervation: deep branch of ulnar nerve.
blood supply: superficial and deep branches of ulnar artery.

Front 49

lumbrical muscles

Back 49

origin: tendons of flexor digitorum profundus, pass lateral to digits.
insertion: radial side of extensor tendons.
action: help flex MCP joints and extend IP joints.
innervation: median nerve (lateral 2), deep branch of ulnar nerve (medial 2).

Front 50

adductor pollicis muscle

Back 50

origin: transverse (from 2nd, 3rd, and 4th metacarpal bones) and oblique heads (from capitate).
insertion: medial side of proximal phalanx of thumb.
action: adducts thumb.
innervation: deep branch of ulnar nerve.

Front 51

palmar interosseous muscles

Back 51

origin: metacarpal bone.
insertion: base of proximal phalanx and extensor tendon of digit acted upon.
action: adduct digits.
innervation: deep branch of ulnar nerve.

Front 52

dorsal interosseous muscles

Back 52

origin: adjacent metacarpal bones.
insertion: base of proximal phalanx and extensor tendon.
action: abduct digits.
innervation: deep branch of ulnar nerve.

Front 53

extensor carpi radialis longus

Back 53

origin: lateral supracondylar ridge.
insertion: base of second metacarpal.
action: extend and radial abduct hand at wrist.
innervation: main trunk of radial nerve.
compartment: 2nd.

Front 54

extensor carpi radialis brevis

Back 54

origin: lateral epicondyle of humerus.
insertion: base of 3rd metacarpal.
innervation: deep branch of radial nerve.
compartment: 2nd.

Front 55

extensor digitorum

Back 55

origin: lateral epicondyle of humerus.
insertion: extensor hood to middle (central bands) and distal (lateral bands) phalanges of 4 fingers.
innervation: posterior interosseous nerve.
compartment: 4th.

Front 56

extensor digiti minimi

Back 56

origin: lateral epicondyle of humerus.
insertion: extensor hood of little finger.
innervation: posterior interosseous nerve.
compartment: 5th.

Front 57

extensor carpi ulnaris

Back 57

origin: lateral epicondyle of humerus.
insertion: base of 5th metacarpal.
innervation: posterior interosseous nerve.
compartment: 6th.

Front 58

anconeus muscle

Back 58

origin: lateral epicondyle of humerus.
insertion: upper 1/4 of ulna.
action: stabilizes elbow joint and assists in flexion at elbow.
innervation: main trunk of radial nerve.

Front 59

supinator muscle

Back 59

origin: ulna and lateral epicondyle of humerus, wraps around radius.
insertion: medial surface of radius.
action: supinates forearm.
innervation: deep branch of radial nerve.

Front 60

abductor pollicis longus

Back 60

origin: radius and ulna.
insertion: base of 1st metacarpal.
action: abducts thumb.
innervation: posterior interosseous nerve.
compartment: 1st.

Front 61

extensor pollicis brevis

Back 61

origin: radius.
insertion: proximal phalanx of thumb.
action: extends thumb.
innervation: posterior interosseous nerve.
compartment: 1st.

Front 62

extensor pollicis longus

Back 62

origin: ulna.
insertion: base of distal phalanx of thumb.
action: extends thumb.
innervation: posterior interosseous nerve.
compartment: 3rd (changes direction at radial tubercle).

Front 63

extensor indicis muscle

Back 63

origin: ulna.
insertion: extensor hood of index finger.
action: extends index finger.
innervation: posterior interosseous nerve.
compartment: 4th.