Psychology Chapter 8 Homework Instructor Guide For Human Anatomy Amp Physiology

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CHAPTER

Joints

Objectives

Classification of Joints

1. Define joint or articulation.

Fibrous Joints

3. Describe the general structure of fibrous joints. Name and give an example of each of the

three common types of fibrous joints.

Cartilaginous Joints

Synovial Joints

6. Compare the structures and functions of bursae and tendon sheaths.

8. Name and describe (or perform) the common body movements.

10. Describe the elbow, knee, hip, jaw, and shoulder joints in terms of articulating bones,

anatomical characteristics of the joint, movements allowed, and joint stability.

Homeostatic Imbalances of Joints

11. Name the most common joint injuries and discuss the symptoms and problems associated

with each.

Developmental Aspects of Joints

14. Discuss factors that promote or disturb joint homeostasis.

Suggested Lecture Outline

I. Classification of Joints (pp. 249–250; Figs. 8.1–8.3; Tables 8.1–8.2)

A. Structural classification focuses on the material binding the bones together and whether

or not a joint cavity is present (p. 249; Table 8.1).

1. Structurally, joints may be fibrous, cartilaginous, or synovial.

II. Fibrous Joints (pp. 250–251; Fig. 8.1; Tables 8.1–8.2)

A. In fibrous joints, bones are joined together by fibrous tissue and lack a joint cavity, and

provide little to no movement (p. 250).

B. There are three types of fibrous joints: sutures, syndesmoses, and gomphoses (pp. 250–

251; Fig. 8.1).

1. Sutures occur between bones of the skull and use very short connective tissue fibers to

hold the bones together.

III. Cartilaginous Joints (pp. 251–252; Fig. 8.2; Tables 8.1–8.2)

A. In cartilaginous joints, the bones are joined together by cartilage, they lack a joint cavity,

and have very little mobility (p. 251).

IV. Synovial Joints (pp. 252–269; Figs. 8.3–8.13; Tables 8.1–8.2)

A. Synovial joints have a structure that allows free movement about the joint (p. 252).

B. The general structure of a synovial joint contains six distinguishing features

(pp. 252–253; Fig. 8.3).

1. Articular cartilage covers the ends of the articulating bones.

C. Bursae and tendon sheaths contain lubricant that reduces friction at synovial joints

(p. 253; Fig. 8.4).

D. Factors Influencing the Stability of Synovial Joints (pp. 255–256)

1. The shapes of the articular surfaces of bones found at a synovial joint determine the

movements that occur at the joint, but play a minimal role in stabilizing the joint.

E. Movements Allowed by Synovial Joints (pp. 256–258; Figs. 8.5–8.6; Table 8.2)

1. Skeletal muscles attach to bones or other connective structures at two points: the

origin, attached to the immovable bone; and the insertion, attached to the movable

bone.

3. Angular movements increase or decrease the angle between two bones.

a. Flexion decreases the angle of the joint and brings the articulating bones closer

together.

b. Extension increases the angle between the articulating bones.

4. Rotation is the turning of a bone along its own long axis.

5. Special Movements

a. Supination is rotating the forearm laterally so that the palm faces anteriorly or

superiorly.

b. Pronation is rotating the arm medially so that the palm faces posteriorly or

inferiorly.

F. Types of Synovial Joints (p. 258; Fig. 8.7; Table 8.2)

1. Plane joints have flat articular surfaces and allow gliding and transitional movements.

2. Hinge joints consist of a cylindrical projection that nests in a trough-shaped structure,

and allow movement along a single plane.

3. Pivot joints consist of a rounded structure that protrudes into a sleeve or ring, and

allow uniaxial rotation of a bone around the long axis.

G. Selected Synovial Joints (pp. 262–269; Figs. 8.8–8.13; Table 8.2)

1. Knee Joint

a. The single cavity of the knee joint is actually three joints in one: the femoropatellar

joint, the lateral and medial joints between the femoral condyles, and the menisci of

the tibia, known collectively as the tibiofemoral joint.

i. The tibiofemoral joint is a hinge joint, allowing mostly flexion and extension,

although limited rotation is possible when the knee is bent.

2. Shoulder (Glenohumeral) Joint

a. The shoulder joint is a ball-and-socket joint that is the most freely moving joint in

the body, although it is not a very stable joint.

3. Elbow Joint

a. The joint between the ulna and humerus provides a stable and smoothly operating

hinge joint that allows flexion and extension only.

4. Hip (Coxal) Joint

a. The hip joint is a ball-and-socket joint that provides a wide range of motion.

b. Several strong ligaments reinforce the capsule of the hip joint.

5. Temporomandibular Joint

a. The temporomandibular joint allows both hingelike movement and side-to-side

lateral excursion.

V. Homeostatic Imbalances of Joints (pp. 269–272; Figs. 8.14–8.15)

A. Common Joint Injuries (pp. 269–270; Fig. 8.14)

1. Sprains and dislocations are the most common joint injuries.

2. Cartilage tears often occur at the knee, when a meniscus is subjected to compression

and shear stress at the same time.

B. Inflammatory and Degenerative Conditions (pp. 270–272; Fig. 8.15)

1. Bursitis, an inflammation of the bursa, is usually caused by a blow or friction, while

tendonitis is inflammation of the tendons, and is usually caused by overuse.

2. Arthritis describes many inflammatory or degenerative diseases that damage the joints,

resulting in pain, stiffness, and swelling of the joint.

a. Osteoarthritis is the most common chronic arthritis. It is the result of breakdown of

VI. Developmental Aspects of Joints (pp. 272–273)

A. In an embryo, joints develop at the same time as bones, and resemble adult joints by

week 8 (p. 272).

B. During childhood, use defines the size, shape, and flexibility of joints (p. 272).

Cross References

Additional information on topics covered in Chapter 8 can be found in the chapters listed below.

1. Chapter 1: Planes of the body

2. Chapter 4: Ligaments and tendons (dense connective tissue); hyaline cartilage;

fibrocartilage

Lecture Hints

1. Clearly distinguish between the two systems of joint classification (structural and

functional).

5. If only one synovial joint will be studied in detail, the best choice is the knee.

6. To help students understand the significance of the form of bones at joints, demonstrate

the structural similarities of synovial joints in different body locations that fall within the

same structural class.

Activities/Demonstrations

1. Audiovisual materials are listed in the Multimedia in the Classroom and Lab section of

this Instructor Guide (p. 387).

2. Call on students to demonstrate the various types of body movements: abduction,

adduction, flexion, extension, etc., occurring at specific joints (e.g., flex your knee, rotate

your hand).

6. Obtain a video or request that a local orthopedic surgeon visit the class and describe the

techniques and advantages of arthroscopic knee surgery.

Critical Thinking/Discussion Topics

1. Why are diarthroses found predominantly in the limbs while synarthroses and

amphiarthroses are found largely in the axial skeleton?

2. What are the advantages of the shoulder joint being the most freely moving joint in the

body?

Library Research Topics

1. People often injure their joints during sports activities. What are the major joint injuries

associated with football, basketball, baseball, and tennis?

4. Temporomandibular joint disorders are very painful. What methods of treatment are

there, and how successful are they? How do these joint disorders arise?

5. Much controversy surrounds the use of the drug dimethyl sulfoxide (DMSO). Why is the

FDA so reluctant to provide full approval of this drug for use on humans when it’s wide-

ly used for horses?

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 8.1 Fibrous joints.

Figure 8.7 Synovial Joints.

Figure 8.8 The knee joint.

Figure 8.9 A common knee injury.

Figure 8.10 The shoulder joint.

Figure 8.11 The elbow joint.

Figure 8.12 The hip joint.

Answers to End-of-Chapter Questions

Multiple-Choice and Matching Question answers appear in Appendix H of the main text.

Short Answer Essay Questions

8. Joints are defined as sites where two or more bones meet. (p. 249)

9. Freely movable joints provide mobility; slightly movable joints provide strength with

10. Bursae are synovial membrane-lined sacs that function to prevent friction, and are

11. Nonaxial movements mean slipping movements only, uniaxial movements mean move-

12. Flexion and extension refer to decreasing or increasing the angle of a joint and bringing

13. Rotation means to turn a bone around its own long axis, while circumduction means to

move a limb so that it describes a cone in space, an action that involves a variety of

movements. (p. 258)

14. Uniaxial joints include hinge (elbow) and pivot (atlantoaxial and radioulnar) joints;

15. The knee menisci deepen the articulating surface of the tibia to prevent side-to-side

16. The knees must carry the total body weight and rely heavily on nonarticular factors for

17. Sprains and cartilage injuries are particularly problematic because cartilage and liga-

ments are poorly vascularized and tend to heal very slowly. (p. 264)

18. The fibrous layer, composed of dense irregular connective tissue, is the external layer of

the articular capsule and strengthens the joint so that the bones are not pulled apart. Syn-

ovial fluid occupies all free spaces within the articular capsule, including that within the

Critical Thinking and Clinical Application Questions

2. a. The ankle joint is not really a stable joint. The shape of the articular surfaces is not as

enclosed as other joints and has a greater degree of flexibility due to the fact that three

bones, not two, create the joint. Also, there are relatively few strong muscles and lig-

aments that cross this joint, compared to other joints, such as the hip or knee.

3. a. Mrs. Bell’s arthritis is probably due to gout, although gout is more common in males.

b. Arthritis due to gout is caused by a deposition of uric acid crystals in soft tissues of

joints. (p. 270)

4. The vector for the bacteria that causes Lyme disease is the deer tick, a very small tick

carried by deer and other small mammals. (p. 270)