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CHAPTER
7
The Skeleton
Objectives
Part 1: The Axial Skeleton
1. Name the major parts of the axial and appendicular skeletons and describe their relative
functions.
The Skull
2. Name, describe, and identify the skull bones. Identify their important markings.
The Vertebral Column
5. Describe the structure of the vertebral column, list its components, and describe its
curvatures.
The Thoracic Cage
8. Name and describe the bones of the thoracic cage (bony thorax).
9. Differentiate true from false ribs.
Part 2: The Appendicular Skeleton
The Pectoral (Shoulder) Girdle
10. Identify bones forming the pectoral girdle and relate their structure and arrangement to
the function of this girdle.
14. Describe differences in the male and female pelves and relate these to functional
differences.
The Lower Limb
15. Identify the lower limb bones and their important markings.
Suggested Lecture Outline
Part 1: The Axial Skeleton
I. The Skull (pp. 202–211; Figs. 7.1–7.10; Table 7.1).
A. The skull consists of 22 cranial and facial bones that form the framework of the face,
contain cavities for special sense organs, provide openings for air and food passage,
secure the teeth, and anchor muscles of facial expression (p. 201).
are flat bones joined by interlocking joints called sutures (p. 201).
C. Overview of Skull Geography (pp. 201–202)
1. The anterior aspect of the skull is formed by facial bones, and the remainder is formed
by a cranium, which is divided into the cranial vault, or calvaria, and cranial base.
D. The cranium consists of eight strong, superiorly curved bones (pp. 202–210; Figs.
7.1–7.10; Table 7.1).
1. The frontal bone articulates posteriorly with the parietal bones via the coronal suture,
extends forward to the supraorbital margins, and extends posteriorly to form the supe-
rior wall of the orbits and most of the anterior cranial fossa.
2. The parietal bones are two large, rectangular bones on the superior and lateral aspects
3. The occipital bone articulates with the parietal, temporal, and sphenoid bones, forming
4. The temporal bones articulate with the parietal bones and form the inferolateral
aspects of the skull and parts of the cranial base.
a. The temporal bone is characterized by the mandibular fossa, which forms part of
the temporomandibular joint, and the external auditory meatus and petrous, which
house the ear.
E. Facial Bones (pp. 211–212; Fig. 7.11; Table 7.1)
1. The mandible, or lower jawbone, articulates with the mandibular fossae of the tempo-
ral bones via the condylar processes to form the temporomandibular joint.
2. The maxillary bones form the upper jaw and central portion of the face, articulating
with all other facial bones except the mandible.
5. The lacrimal bones are located in the medial wall of the orbits and articulate with the
frontal, ethmoid, and maxillary bones.
F. Special Characteristics of the Orbits and Nasal Cavity (pp. 212–215; Figs. 7.12–7.14;
Table 7.1)
1. The orbits are bony cavities that contain the eyes, muscles that move the eyes, and
tear-producing glands. They consist of the frontal, sphenoid, zygomatic, maxilla,
palatine, lacrimal, and ethmoid bones.
G. The hyoid bone lies inferior to the mandible in the anterior neck. It is the only bone that
does not articulate directly with any other bone (p. 215; Fig. 7.15).
II. The Vertebral Column (pp. 218–224; Figs. 7.16–7.22; Table 7.2)
A. General Characteristics (pp. 218–220; Figs. 7.16–7.18)
1. The vertebral column consists of 26 irregular bones, forming a flexible, curved struc-
ture extending from the skull to the pelvis that surrounds and protects the spinal cord
and provides attachment for ribs and muscles of the neck and back.
2. Divisions and Curvatures
a. The vertebrae of the spine fall in five major divisions: seven cervical, twelve
3. The major supporting ligaments of the spine are the anterior and posterior longitudinal
ligaments, which run as continuous bands down the front and back surfaces of the
spine, supporting the spine and preventing hyperflexion and hyperextension.
B. General Structure of Vertebrae (pp. 220–221; Fig. 7.19)
1. Each vertebra consists of an anterior body and a posterior vertebral arch that, together
with the body, form the vertebral foramen through which the spinal cord passes.
C. Regional Vertebral Characteristics (pp. 221–224; Figs. 7.20–7.22; Table 7.2)
1. Cervical vertebrae are the smallest vertebrae, typically having an oval body, a short,
bifid spinous process, a large triangular vertebral foramen, and a transverse foramen.
2. Thoracic vertebrae all articulate with ribs and gradually transition between cervical
structure at the top, and lumbar structure toward the bottom.
a. Thoracic vertebrae have a roughly heart-shaped body, which bear two facets on
each side for rib articulation: a circular vertebral foramen and superior and inferior
articular processes.
3. Lumbar vertebrae are large vertebrae that have kidney-shaped bodies, a triangular
4. The sacrum forms the posterior wall of the pelvis, formed by five fused vertebrae in
adults, and articulates with the fifth lumbar vertebra superiorly, the coccyx inferiorly,
and the hip bones laterally via the sacroiliac joint.
5. The coccyx (tailbone) is a small bone consisting of four, fused vertebrae that articulate
superiorly with the sacrum.
III. The Thoracic Cage (pp. 224–227; Figs. 7.23–7.24)
A. The thoracic cage consists of the thoracic vertebrae dorsally, the ribs laterally, and the
sternum and costal cartilages anteriorly, forming a protective cage around the organs
of the thoracic cavity, and providing support for the shoulder girdles and upper limbs
(pp. 224–225; Fig. 7.23).
C. Ribs (pp. 226–227; Figs. 7.23–7.24)
1. The sides of the thoracic cage are formed by twelve pairs of ribs that attach posteriorly
to the thoracic vertebrae and curve inferiorly toward the anterior body surface.
Part 2: The Appendicular Skeleton
IV. The Pectoral (Shoulder) Girdle (pp. 227–229; Figs. 7.25–7.26; Table 7.3)
A. The pectoral (shoulder) girdle consists of the clavicle, which joins the sternum anteriorly,
and the scapula, which is attached to the posterior thorax and vertebrae via muscular
attachments (pp. 227–228; Fig. 7.25).
1. The pectoral girdle is very light and has a high degree of mobility due to the openness
of the shoulder joint and the free movement of the scapula across the thorax.
V. The Upper Limb (pp. 228–234; Figs. 7.27–7.29; Table 7.3)
A. Arm (pp. 228, 230; Fig. 7.27; Table 7.3)
2. The humerus is the largest, longest bone of the upper limb and articulates with the
scapula at the shoulder, and with the radius and ulna at the elbow.
B. Forearm (pp. 231–232; Fig. 7.28; Table 7.3)
1. The forearm is the region between the elbow and wrist and consists of two bones, the
ulna and the radius.
C. Hand (pp. 232–234; Fig. 7.29; Table 7.3)
1. The carpus (wrist) consists of eight short bones arranged in two irregular rows of four
bones each.
a. The proximal row consists of the scaphoid, lunate, triquetrum, and pisiform.
b. The distal row consists of the trapezium, trapezoid, capitate, and hamate.
VI. The Pelvic (Hip) Girdle (pp. 234–238; Figs. 7.30–7.31; Tables 7.4–7.5)
A. The pelvic girdle attaches the lower limbs to the axial skeleton and is formed by the
sacrum (a part of the axial skeleton); and a pair of coxae, each consisting of three
separate but fused bones: the ischium, ilium, and pubis (p. 234; Fig. 7.30).
B. The ilium forms the superior region of the coxal bone, articulating with the sacrum,
forming the sacroiliac joint, and also anteriorly with the ischium and pubis (pp. 234–235;
Figs. 7.30–7.31).
VII. The Lower Limb (pp. 238–243; Figs. 7.32–7.35; Table 7.5)
A. Thigh (pp. 238–239; Fig. 7.32; Table 7.5)
1. The thigh is the region between the hip and knee and has one bone, the femur.
a. The femur is the largest, longest, and strongest bone in the body, articulating prox-
imally with the hip via a ball-like head, and distally with the knee at the lateral and
medial condyles.
B. Leg (pp. 239–241; Fig. 7.33; Table 7.5)
1. The leg is the region between the knee and ankle and has two bones, the tibia and
fibula.
C. Foot (pp. 241–243; Figs. 7.34–7.35; Table 7.5)
1. The tarsus consists of seven tarsal bones that make up the posterior half of the foot and
includes the calcaneus, talus, cuboid, navicular, and medial, intermediate, and lateral
cuneiform bones.
VIII. Developmental Aspects of the Skeleton (pp. 244–245; Figs. 7.36–7.39)
A. Membrane bones of the skull begin to ossify late in the second month of development
(p. 244).
B. At birth, skull bones are connected by fontanelles, unossified remnants of fibrous
membranes (p. 244; Fig. 7.36).
D. Curvatures of the Spine (pp. 244–245; Fig. 7.38)
1. The primary curvatures (thoracic and sacral curvatures) are convex posteriorly and are
present at birth.
2. The secondary curvatures (cervical and lumbar curvatures) are convex anteriorly and
are associated with the child’s development.
3. The secondary curvatures result from reshaping the intervertebral discs as the baby
begins to lift its head and learns to walk.
3. During puberty, the female pelvis widens, and the male skeleton becomes more robust.
F. Effects of old age on the skeleton (p. 245).
Cross References
Additional information on topics covered in Chapter 7 can be found in the chapters listed below.
1. Chapter 4: Fibrocartilage; hyaline cartilage
2. Chapter 6: Bone markings; classification of bones
Lecture Hints
1. A good indicator of student comprehension of the spatial relationship among facial bones
is the ability to list the bones making up the eye orbit.
2. Point out during the lecture that the styloid process of the temporal bone is often
4. Point out that all facial bones (except the mandible) articulate with the maxillae.
6. “Atlas supports the world” can be used to help students remember that the atlas is first
and axis second.
8. Although the obturator foramen is large, it is nearly closed by a fibrous membrane in life.
Activities/Demonstrations
2. The cranium is remarkably strong for its weight and the thinness of cranial bones. This is
3. Give a group of students a thoracic vertebra and a rib and ask them to articulate the two
together.
5. Use an articulated skeleton to indicate its protective and supportive aspects and to
identify individual bones.
7. Obtain a skull that shows Wormian bones.
9. Use a disarticulated vertebral column to illustrate similarities/differences between
vertebrae.
11. Obtain X rays that exhibit abnormal spinal curvatures (scoliosis, lordosis, kyphosis).
12. Obtain different ribs and indicate how each is similar and different.
13. Point out differences between the male and female pelves.
Critical Thinking/Discussion Topics
1. List several skeletal landmarks that can be used to guide a nurse or physician in giving
injections, locating areas for surgery, and assisting in the diagnosis of internal conditions.
2. What effect would exaggerated exercise or the complete lack of exercise have on bones
such as the tibia, femur, and humerus if it occurred during childhood? During adulthood?
6. Humans have short necks and giraffes have long necks. Does the giraffe have more neck
vertebrae to accommodate this extra length? What other similarities or variations can be
found between human bone structure and that of other animals?
Library Research Topics
1. There is a technique known as percutaneous automated discectomy which involves back
surgery without stitches. How safe is it, and when can it be employed?
4. Paleontologists and archaeologists have unearthed many prehistoric skulls and bones of
humanlike creatures and animals. How can they reconstruct the soft features and tissues
of these animals from only their skeletal remains?
5. Trace the origin of congenital disorders such as spina bifida and cleft palate, starting with
the human embryo. What is the explanation for these defects?
List of Figures and Tables
All of the figures in the main text are available in JPEG format, PPT, and labeled & unlabeled
format on the Instructor Resource DVD. All of the figures and tables will also be available in
Transparency Acetate format. For more information, go to www.pearsonhighered.com/educator.
Figure 7.1 The human skeleton.
Figure 7.5 Bones of the lateral aspect of the skull, external and internal views.
Figure 7.6 Inferior aspect of the skull, mandible removed.
Figure 7.7 The base of the cranial cavity.
Figure 7.8 The temporal bone.
Figure 7.15 The hyoid bone, anterior view.
Figure 7.16 The vertebral column.
Figure 7.17 Abnormal spinal curvatures.
Figure 7.18 Ligaments and fibrocartilage discs uniting the vertebrae.
Figure 7.25 The pectoral girdle and clavicle.
Figure 7.26 The scapula.
Figure 7.27 The humerus of the right arm and detailed views of articulation at
the elbow.
Figure 7.28 Radius and ulna of the right forearm.
Figure 7.29 Bones of the right hand.
Figure 7.37 A baby born with a cleft lip and palate.
Figure 7.38 The C-shaped spine of a newborn infant.
Figure 7.39 Different growth rates of body parts determine body proportions.
Table 7.1 Bones of the Skull
Answers to End-of-Chapter Questions
Multiple-Choice and Matching Question answers appear in Appendix H of the main text.
Short Answer Essay Questions
4. Cranial bones: parietal, temporal, frontal, occipital, sphenoid, and ethmoid. Facial bones:
mandible, vomer, maxillae, zygomatics, nasals, lacrimals, palatines, and inferior conchae.
5. At birth, the skull is huge relative to the facial skeleton. During childhood and adoles-
6. Normal curves are: cervical, thoracic, lumbar, and sacral. The thoracic and sacral are
7. Cervical vertebrae possess transverse foramina, have small bodies and bifurcate spinous
processes; thoracic vertebrae possess facets for the ribs and have circular vertebral
foramina; lumbar vertebrae have massive bodies and blunt spines. (p. 221; Table 7.2)
9. The annulus fibrosis, composed of fibrocartilage, is more external and contains the nucleus
10. a. True ribs attach to the vertebral column and sternum directly at both ends; false ribs
11. The pelvic girdle functions to attach and transfer the weight of the body to the lower
12. The female pelvis inlet and outlet are wider; the pelvis is shallower, lighter, and rounder
than that of the male; and the ischial tuberosities are farther apart. (p. 238; Table 7.4)
13. Both cleft palate and hip dysplasia are congenital abnormalities affecting skeletal for-
mation. A cleft palate occurs if the fusion of the midline of the maxilla fails to occur.
14. In a young adult skeleton, the bone mass is dense, water content is normal in discs, the
vertebral column is strong. In old age, the discs decline in water content and become
15. Peter was having a little fun with the obturator foramen, the large opening in the hip bone
through which pass some blood vessels and nerves. (p. 235)
Critical Thinking and Clinical Application Questions
1. Justiniano is probably suffering from carpal tunnel syndrome, a nerve impairment
2. A lateral curvature is scoliosis due to an uneven pull of muscles. Because muscles on one
3. The fracture of the neck of the femur is usually called a broken hip and is common in the
4. Mrs. Shea has developed soreness on her buttock in response to having her entire weight
on her ischial tuberosity for three days. If she were to continue this activity for a few
more days, she would develop pressure sores called decubitus ulcers. (p. 235)
Suggested Readings
Agur, A. M., and A. F. Dalley. Grant’s Atlas of Anatomy. 12th ed. Baltimore: Lippincott
Williams & Wilkins, 2009.
Chase, R. A. The Bassett Atlas of Human Anatomy. San Francisco: Benjamin Cummings,
1989.
Clemente, C. D. Anatomy: A Regional Atlas of the Human Body. 5th ed. Baltimore:
Lippincott Williams & Wilkins, 2007.
Jayakumar, P., and L. Di Silvio. “Osteoblasts in Bone Tissue Engineering.” Proceedings of
the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 224
