Lab 20

Muscles of the shoulders, arm, and hand

Quiz for next week

• Tuesday or Thursday?

• Same format as today

• Know Upper Arm, Lower Arm, Hip and Thigh, Upper Leg and Lower Leg

Muscles to know

• supraspinatus• infraspinatus• subscapularis• teres major• rhomboid• levator scapulae• deltoid• biceps brachii• brachialis

• triceps brachii• flexor carpi radialis• flexor carpi ulnaris• flexor digitorum sup.• extensor carpi ulnaris• extensor digitorum• extensor carpi radialis• brachioradialis

Cut activity 4

• Only hand muscles you need to know are not explicitly mentioned in the lab (but they do appear in the pictures):– flexor pollicus longus– extensor pollicis longus

Muscles that Move the Arm

Figure 11–15a

Muscles that Move the Arm

Figure 11–15b

Muscles that Move the Arm (1 of 3)

• Deltoid: – the major abductor

• Supraspinatus: – assists deltoid

• Subscapularis and teres major: – produce medial rotation at shoulder

Muscles that Move the Arm (2 of 3)

• Infraspinatus: – produce lateral rotation at shoulder

Muscles that Move the Arm (3 of 3)

• Pectoralis major: – between anterior chest and greater tubercle of

humerus– produces flexion at shoulder joint

• Latissimus dorsi:– between thoracic vertebrae and humerus– produces extension at shoulder joint

The Rotator Cuff

• Muscles involved in shoulder rotation– supraspinatus, subscapularis, infraspinatus,

teres minor,and their tendons

Summary: Muscles that Move the Arm

Table 11–12

Muscles that Position the Pectoral Girdle

• Rhomboid and levator scapulae:– deep to trapezius– attach to cervical and thoracic vertebrae– insert on scapular border

Muscles that Move the Forearm and Hand

• Originate on humerus and insert on forearm

• Exceptions:– the major flexor (biceps brachii)– the major extensor (triceps brachii)

Extensors and Flexors

• Extensors:– mainly on posterior and lateral surfaces of

arm

• Flexors:– mainly on anterior and medial surfaces

Muscles that Move the Forearm and Hand

• Biceps brachii:– flexes elbow– stabilizes shoulder joint– originates on scapula and humerus– inserts on radial tuberosity

Muscles that Move the Forearm and Hand

• Triceps brachii:– extends elbow– originates on scapula (three spots)– inserts on olecranon

• Brachialis and brachioradialis:– assist in flexing elbow (synergists)

Muscles that Move the Forearm and Hand -Extensors

Figure 11–16a

Muscles that Move the Forearm and Hand - Flexors

Figure 11–16b

Muscles that Move the Forearm and Hand

• Flexor carpi ulnaris: – superficial– flexes wrist– adducts wrist

Muscles that Move the Forearm and Hand

• Flexor carpi radialis: – superficial– flexes wrist– abducts wrist

Muscles that Move the Forearm and Hand

• Extensor carpi radialis:– superficial– extends wrist– abducts wrist

Muscles that Move the Forearm and Hand

• Extensor carpi ulnaris:– superficial– extends wrist– adducts wrist

Figure 11–16a

Figure 11–16b

Summary: Muscles that Move the Forearm and Hand

Table 11–13 (1 of 2)

Today

• Work through lab 20

• Relevant parts of lab reports due Next Week