Appendicular Skeleton: Pectoral Girdle

Question 1

Pectoral Girdle

Answer 1

Includes:

• -L and R scapulae
• -L and R clavicles

Note: scapulae do NOT join to axial skeleton at all, and their articulation w/ clavicle is very loose. They’re attached to axial skeleton by way of associated muscles and ligaments. Provides a highly flexible system (lots of movement allowed), but not very stable

Question 2

Pectoral Girdle: Clavicle

Answer 2

“collarbone”

Spans superior thorax horizontally. ‘S’ shaped

Medially the sternal end attaches to manubrium of sternum. Laterally the acromial end articulates w/ acromial process of scapula.

Fxn: provides muscle attachment, acts as brace for scapula and arms, transmit compression forces from arms to axial skeleton

S-shape of clavicle makes it prone to fracturing near the curves. The ligaments are quite strong, so bone often breaks instead of dislocating

Question 3

Pectoral Girdle: Scapula

Answer 3

Located on posterior surface of rib cage

Scapular spine is located on posterior side of scapula

Glenoid cavity (glenoid fossa) articulates w/ humerus (forms shoulder joint)

Coracoid process is attachment point of biceps muscle

Acromion articulates w/ acromial end of clavicle

Infraspinous, supraspinous, and subscapularis fossae hold muscles

Question 4

What 4 groups does the appendicular skeleton include?

Answer 4

Pectoral Girdle
Upper Limb
Pelvic Girdle
Lower Limb