Create a new account

It's simple, and free.

The appendicular skeleton

The appendicular skeleton consists of the pectoral girdle, upper limbs, pelvic girdle, and lower limbs (Appendicular-learntech, 2004; Skeletal, 2004). It comprises 126 bones, four in the pectoral girdle: the scapula (2) and the clavicles (2); 60 in the upper limbs: humerus (2), radius (2), ulna (2), carpals (16), metacarpals (10), and phalanges (28); two in the pelvic girdle (os coxae), femur (2), tibia (2), fibula (2), patella (2), tarsals (14), metatarsals (10), and phalanges (28).

The major function of the pectoral girdle is flexibility, and the major function of the pelvic girdle is stability. Functional differences between the two pairs of limbs in humans is reflected in their structure and in their attachment to the appendicular skeleton (Appendicular Skeleton-predator, 2004). In humans, the arms are not needed for locomotion, and so are freed for manipulating tools and the environment. This can be seen clearly by looking at the bones which comprise the two girdles, and how much motion they allow in the attached limbs. The bones of the pectoral girdle are separate, and relatively lighter in weight, particularly the clavicles. The pectoral girdle is attached to the axial skeleton only at the joint between the clavicle and the sternum (Appendicular Skeleton -predator, 2004). This attachment is weak and unstable, but gives great flexibility and freedom of movement. The arms have full rotation about the shoulder joint

The pelvic girdle, on the other hand, is composed of fused bones, relatively firmly fixed in position and to each other. The attachment of the pelvic girdle to the sacrum is strong and stable, and almost immovable (Appendicular Skeleton-predator, 2004). This restricts the movement of the legs as compared to the movement of the arms: the legs only have limited movement at the pelvic joint. This is because the legs must bear the weight of the body at all times, and keep it stable in an upright post...

Page 1 of 3 Next >

More on The appendicular skeleton...

Loading...
APA     MLA     Chicago
The appendicular skeleton. (1969, December 31). In LotsofEssays.com. Retrieved 11:32, March 29, 2024, from https://www.lotsofessays.com/viewpaper/1707515.html