Lab 5: Myology: Pectoral Area and Ventral Upper Limb

muscles crossing shoulder joint

• pectoralis major

• latissimus dorsi

• deltoid

pectoralis major: action

adducts, flexes and medially rotates arm

pectoralis major: origin

clavicle, sternum, and ribs

pectoralis insertion:

humerus (intertubercular sulcus)

pectoralis major: human or cat

both

latissmus dorsi: action

adducts, extends, and medially rotates arm

latissmus dorsi: origin

scapula, vertebral column, and iliac crest

latissmus dorsi: insertion

humerus (intertubercular sulcus)

deltoid: action

abducts, flexes, and rotates arm medially and laterally

deltoid: origin

clavicle and scapula

deltoid: insertion

deltoid tuberosity of humerus

deltoid: human or cat

both

posterior thorax

• trapezius

• lavator scapulae

trapezius: action

adducts and rotates scapula; elevation and depression of scapula

trapezius: origin

superior nuchal line of occipital bone and vertebral column

trapezius: insertion

lateral clavicle and scapular spine and acromion

trapezius: human or cat

both

levator scapulae: action

elevation of scapula, lateral neck flexion

levator scapulae: origin

transverse processes of cervical vertebrae (C1-C4)

levator scapulae: insertion

medial border (scapula)

levator scapulae: human or cat

both

anterior thorax

• pectoralis minor

pectoralis minor: action

stabilizes, abducts, and rotates scapula

pectoralis minor: origin

ribs 3-5

pectoralis minor: insertion

scapula (coracoid process)

pectoralis minor: human or cat

both

shoulder joint

• subscapularis

• infraspinatus

• supraspinatus

• teres minor

• teres major

• coracobrachialis

subscapularis: action

medial rotation of arm, stabilizes humerus head in glenoid cavity

subscapularis: origin

subscapular fossa of scapula

subscapularis: insertion

lesser tubercle of humerus

subscapularis: human or cat

both

infraspinatus: action

lateral rotation of arm, stabilizes humerus head in glenoid cavity

infraspinatus: origin

infraspinous fossa of scapula

infraspinatous: insertion

greater tubercle of humerus

infraspinatus: human or cat

both

supraspinatus: action

abduction of arm, stabilizes humerus head in glenoid cavity

supraspinatus: origin

supraspinous fossa of scapula

supraspinatus: insertion

greater tubercle of humerus

supraspinatus: human or cat

both

teres minor: action

lateral rotation and adduction of arm, stabilizes humerus head in glenoid cavity

teres minor: origin

lateral border of scapula

teres minor: insertion

greater tubercle of humerus

teres major: action

medial rotation, adduction & extension of arm

teres major: origin

inferior angle and lateral border of scapula

teres major: insertion

intertubercular sulcus of humerus

teres major: human or cat

both

coracobrachialis: action

flexion and adduction of arm

coracobrachialis: origin

coracoid process of scapula

coracobrachialis: insertion

mid-shaft of humerus

coracobrachialis: human or cat

both

anterior arm muscles

• biceps brachii (long and short head)

• brachialis

biceps brachii: action

supination and flexion of forearm

biceps brachii: origin

supraglenoid tubercle and coracoid process of scapula

biceps brachii: insertion

radial tuberosity

biceps brachii: human or cat

both

brachialis: action

flexion of forearm

brachialis: origin

anterior distal shaft of humerus

brachialis: insertion

ulnar tuberosity and coranoid process of ulna

brachialis: human or cat

both

posterior arm

• triceps brachii (long, lateral, and medial head)

triceps brachii: action

extension of forearm; stabilizes shoulder joint

triceps brachii: origin

infraglenoid tubercle (scapula) and proximal posterior shaft of humerus

triceps brachii: insertion

olecranon process (ulna)

triceps brachii: human or cat

both

anterior superficial forearm

• flexor carpi radialis

• palmaris longus

• flexor carpi ulnaris

• pronator teres

flexor carpi radialis: action

wrist flexion and hand abduction

flexor carpi radialis: origin

medial epicondyle (humerus)

flexor carpi radialis: insertion

metacarpals II and III

flexor carpi radials: human or cat

both

palmaris longus: action

wrist flexion (weak)

palmaris longus: origin

medial epicondyle (humerus)

palmaris longus: insertion

palmar-aponeurosis (sheet-like tendon)

palmaris longus: human or cat

both

flexor carpi ulnaris: action

wrist flexion and hand adduction

flexor carpi ulnaris: origin

medial epicondyle of humerus and olecranon process and posterior border (ulna)

flexor carpi ulnaris: insertion

pisiform and hamate (carpal bones)

flexor carpi ulnaris: human or cat

both

pronator teres: action

forearm pronation

pronator teres: origin

medial epicondyle (humerus) and coronoid process of ulna

pronator teres: insertion

lateral mid-shaft of radius

pronator teres: human or cat

both

posterior superficial forearm

• extensor carpi radialis longus

• extensor carpi radialis brevis

• extensor digitorum

• extensor carpi ulnaris

extensor carpi radialis longus: action

extension of wrist and abduction of hand

extensor carpi radialis longus: origin

supracondylar ridge (humerus)

extensor carpi radialis longus: insertion

metacarpal II

extensor carpi radialis brevis: action

extension of wrist and abduction of hand

extensor carpi radialis brevis: origin

lateral epicondyle (humerus)

extensor carpi radialis brevis: insertion

metacarpal III

extensor digitorum: action

extension of wrist and fingers (2-5)

extensor digitorum: origin

lateral epicondyle (humerus)

extensor digitorum: insertion

phalanges II-V

extensor digitorum: human or cat

both

extensor carpi ulnaris: action

extension of wrist; adduction of wrist

extensor carpi ulnaris: origin

lateral epicondyle (humerus) and ulna

extensor carpi ulnaris: insertion

metacarpal V

extensor carpi ulnaris: human or cat

both

posterior deep forearm

• abductor pollicis longus

• extensor pollicis longus

• supinator

abductor pollicis longus: action

abduction and extension of thumb

abductor pollicis longus: origin

radius and ulna (both proximal posterior); interosseous membrane

abductor pollicis longus: insertion

metacarpal I (base)