The Appendicular Skeleton Appendicular Skeleton A. bones of the limbs 1. arms 2. legs B. girdles 1. pectoral 2. pelvic

The pectoral girdle and upper limbs 1. Pectoral Girdle a. 2 clavicles 1. articulate with manubrium of sternum 2. only direct connection between pectoral girdle and axial skeleton b. 2 scapulae 1. skeletal muscles support and position 2. therefore shoulders are extremely mobile but not very strong

c. provides base for arm movement d. surfaces of clavicles and scapulae are important sites for muscle attachment

e. The Clavicles 1.articulate with the manubrium and scapulae 2. relatively small and fragile(easily broken) f. The Scapulae 1.articulates with clavicles and humerus (shoulder joint) 2. anterior surface of the body of each scapulae forms a triangle( muscles that position the scapulae attach at the edges)

2. The Upper Limbs a. includes bones of the following: 1. arms(humerus) 2. forearms(radius and ulna) 3. wrists( carpal bones) 4. hands( metacarpals and phalanges)

b. upper arm consists of the humerus 1. extends from scapula to the elbow 2. proximal end articulates with scapula while distal end articulates with bones of the forearm 3. 4 major areas: a. head- articulates with scapula to form the shoulder b. shaft- long portion of the bone

C. surgical neck 1. metaphysis of the growing bone 2. fractures typically occur here D. condyle- articulation with bones of the forearm

C. Forearms 1. consists of the ulna and radius 2. in the anatomical position, the ulna lies medial to the radius 3. Ulna a. the olecranon is the point of the elbow b. the head articulates with wrist by articular cartilage

4. Radius a. the lateral bone of the forearm b. the distal end of the radius articulates with the ulnar head at the ulnar notch( permits rotation)

d. Carpal bones( wrists) 1. eight different bones 2. 4 proximal carpals and 4 distal carpals 3. articulate with one another at joints that permit limited sliding and twisting 4. inflammation of the connective tissues can compress the tendons and adjacent nerves a. produces pain and loss of wrist mobility b. is called carpal tunnel syndrome

e. the hand 1. 5 metacarpal bones support the hand finger bones( phalanges) thumb(pollex) has 2 phalanges other fingers have 3 phalanges