The Appendicular Skeleton

a. The appendicular skeleton is made up of the skeletal elements of the upper and lower members (often incorrectly referred to as the "extremities"). These members are appended (attached) to the axial skeleton.

b. The general pattern of construction of the upper and lower members is the same as follows:

(1) Girdle. The girdle is the actual attaching part. It attaches (appends) the limb (the member less the girdle) to the axial skeleton.

(2) Proximal limb segment. The proximal segment of the limb has a single long bone.

(3) Middle limb segment. The middle segment of the limb has two long bones parallel with each other.

(4) Distal limb segment. The distal segment of the limb is made up of many long and short bones. These bones are arranged into a five-rayed pattern--the digits.

c. See table 4-2 for the main bones of the upper and lower members. Figures 4-7 through 4-13 give the main characteristics and details of the bones of the appendicular skeleton.

PART

UPPER MEMBER

LOWER MEMBER

GIRDLE

PECTORAL GIRDLE (CLAVICLE AND SCAPULA)

PELVIC GIRDLE(PELVIC BONE--A FUSION OF ILIUM, PUBIS, AND ISCHIUM)

PROXIMAL SEGMENT

HUMERUS

FEMUR

MIDDLE SEGMENT

RADIUS ULNA

TIBIA FIBULA

DISTAL SEGMENT

CARPUS (8 WRIST BONES) METACARPALS (5) PHALANGES (5 DIGITS)

TARSUS (7 ANKLE BONES) METATARSALS (5) PHALANGES (5 DIGITS)

Table 4-2. Bones of the upper and lower members.

Table 4-2. Bones of the upper and lower members.

Continue with Exercises

Figure 4-7. A general pattern of the upper and lower members.
Figure 4-8. The human scapula and clavicle (pectoral girdle).
Figure 4-9. The humerus, radius, and ulna.

PHALANGES

Figure 4-10. The human hand.

PHALANGES

Figure 4-10. The human hand.

Figure 4-11. The bony pelvis (two pelvic bones and sacrum).
Figure 4-12. The femur, tibia, and fibula (anterior views).
Figure 4-13. The human foot.
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