4-38. GENERAL STRUCTURE OF THE LIMBS
Both the upper and lower members have limbs arranged in three segments. The
proximal segment has one bone. The middle segment has two bones. The distal
segment has many bones arranged in a five-rayed (pentadactyl) pattern.
4-39. FUNCTIONS OF THE LOWER MEMBER
a. Body Support. The skeleton of the lower member is strongly constructed in
a columnar fashion for body support. The foot at the lower end of the lower limb
extends at a 90 angle. Therefore, the foot forms a base for the body during the erect,
standing posture.
b. Locomotion. At the same time, the lower limb has a series of linkages that
enable the body to move from place to place.
4-40. FUNCTIONS OF THE UPPER MEMBER
The grasping hand is the distal segment of the upper member. The flexible
construction of the pectoral girdle and the bones of the upper limb serve to place the
grasping hand into as many positions as possible. This is particularly helpful in
grasping food and placing it into the mouth. The grasping hand also serves as a
tool-holding device. (When we study the nervous system, we shall see that a significant
portion of the brain and special pathways are present in order to control the movements
of this grasping hand.)
MD0007
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