Chapter 8
Bones, Part 2: The Appendicular
Skeleton
I. The Appendicular Skeleton
A. The appendicular skeleton consists of the pectoral and pelvic girdles and the bones of the upper and lower
limbs.
II. The Pectoral Girdle (pp. 182–185, Figs. 8.1–8.2)
A. The pectoral girdle (shoulder girdle) is composed of a clavicle and scapula; the paired girdles do not form a
complete ring as the term girdle implies.
1. Pectoral girdles are specialized for mobility and attach the upper limbs to the bony thorax.
B. The “S”-shaped clavicle (collarbone) functions as a brace for the shoulder; it also provides sites for muscle
attachments.
1. Clavicles articulate with the sternum of the axial skeleton as well as the scapulae. Additionally, a ligament
runs from the clavicle to the first rib.
C. The scapula articulates with a clavicle and humerus.
III. The Upper Limb (pp. 185–190, Figs. 8.3–8.7, and Table 8.1)
A. The upper limb (extremity) is made up of 30 bones and forms the arm, forearm, and hand; it is specialized for
mobility.
B. The humerus is the only bone of the arm or brachium.
C. Two parallel long bones, the radius and ulna, form the skeleton of the forearm or antebrachium.
D. The skeleton of the hand includes the eight carpals of the wrist or carpus; the palm or metacarpus consists of
five small long bones numbered 1–5; the digits, or fingers, consist of 14 miniature long bones called phalanges.
IV. The Pelvic Girdle (pp. 192–196, Figs. 8.8–8.9, and Table 8.2)
A. The pelvic girdle (hip girdle) attaches the lower limbs to the spine of the axial skeleton and supports visceral
organs of the pelvis.
B. It is formed by a pair of coxal bones each consisting of three separate bones—the ilium, ischium, and pubis—
that are fused in adults.
C. The coxal bones articulate with the sacrum to form the basin-like bony pelvis.
D. The female pelvis is modified in several ways to accommodate childbearing.
V. The Lower Limb (pp. 196–200, Figs. 8.10–8.13, and Table 8.1)
A. The three segments of the lower limb (extremity) are the thigh, leg, and foot; collectively, 30 bones compose
the lower limb; it is specialized for weight bearing and locomotion.
B. The femur is the only bone of the thigh.
C. The leg is the region between the knee and foot and it has two bones, the tibia and fibula.
D. The skeleton of the foot includes the seven tarsal bones of the tarsus; the metatarsus contains the five
metatarsals numbered 1–5, and the digits or toes contain 14 phalanges.
E. The foot is supported by three arches that distribute the weight of the body to the heel and ball of the foot.
VI. Disorders of the Appendicular Skeleton (pp. 200–201)
A. Most disorders are bone fractures; other significant disorders are birth defects, such as hip dysplasia and
clubfoot.
VII. The Appendicular Skeleton Throughout Life (201, Fig. 8.14)
A. During growth, the arms and legs grow faster than the head and trunk.
1. At birth, the head and trunk are roughly 1.5 times the length of the lower limbs.
2. Lower limbs grow more rapidly than the trunk and at age 10, the head and trunk are about the same length as
the lower limbs.
B. After middle age, all bones lose bone mass; osteoporosis and limb fractures become more common.
SUPPLEMENTAL STUDENT MATERIALS to Human Anatomy,
Fifth Edition
Chapter 8: Bones, Part 2: The Appendicular Skeleton
To the Student
Chapter 8 is an introduction to the bones of the appendicular portion of the human skeleton. Of the 206 total bones in
the body, you mastered all the bones of the skull, vertebral column, and rib cage in the preceding chapter. This chapter
covers the remaining bones. Continued mastery of new terminology is necessary. Your goal is to understand how
individual bones of the appendicular skeleton form the pectoral and pelvic girdles and upper and lower limbs.
Step 1: Distinguish between the axial and appendicular skeletons.
- Name the bones of the axial skeleton.
- Name the bones of the appendicular skeleton.
Step 2: Understand the bones that form the pectoral girdle and upper limb.
- Name the bones that form the pectoral girdle.
- Explain how bones of the pectoral girdle articulate with each other.
- Explain the functions of the pectoral girdle.
- Indicate major bone markings of the bones of the pectoral girdle and upper limb.
- Describe the bones of the arm, forearm, wrist, and hand, including articulations.
Step 3: Understand the bones that form the pelvic girdle and lower limb.
- Name the bones that form the pelvic girdle.
- Explain the articulations between the bones forming the pelvic girdle.
- List the functions of the pelvic girdle.
- Indicate major bone markings of the bones of the pelvic girdle and lower limb.
- Compare and contrast male and female pelves.
- Describe the bones of the thigh, leg, and foot, including articulations.