SOLUTIONS TO EXERCISES, LESSON 4

SOLUTIONS TO EXERCISES, LESSON 4

1. The skeleton is a combination of bones joined together that serves as a support or framework of the human body. (para 4-1)

2. The four functions of the human skeleton are:

a. Bodily support.

b. Protection.

c. Motion.

d. Formation of blood cells. (para 4-2)

3. An individual bone consists of the outer cortex and the inner medulla. (para 4-4a)

4. The two types of bone marrow are red bone marrow and yellow bone marrow. Yellow bone marrow is mostly yellow fat tissue. Red bone marrow is the only site in adults for the formation of red blood cells. (para 4-4b)

5. The parts or portions of an individual long bone are the shaft (diaphysis) and the ends (epiphyses). The shaft is the central portion of the long bone. The ends are made up mainly of cancellous (spongy) bone tissue. An articular or cartilage covers each area where a bone contacts another bone. (para 4-4c)

6. The periosteum is a covering of bone surface area not covered by articular cartilage. The innermost layer is the osteogenic (bone-forming) layer. The outermost layer is an FCT layer. (para 4-4d)

7. In the early fetus, bones are "preformed" as membranous bones and cartilage bones which have the shape and location of the adult bones. Developing long bones have growing masses of actual bone called ossification centers. These centers are located in the shaft and in each end. Preforming material surrounding these centers is destroyed and replaced with bony tissue. A bone grows in width through the activity of the osteogenic layer of the periosteum. (paras 4-5a, c, d)

8. Four types of bones according to shape are:

a. Long bones.

b. Short bones.

c. Flat bones.

d. Irregular bones. (para 4-6)

9. A syndesmosis is a joint in which the bones are held together by FCT (fibrous connective tissue). (para 4-8a(1))

10. A suture is a joint in which the bones are very close together with a minimum of FCT. (para 4-8a(2))

11.A synosteosis is a joint in which the bones are united by bony material. (para 4-8b)

12. A synchondrosis is a joint in which the bones are held together by hyaline cartilage. (para 4-8c(1))

13. A symphysis is a joint in which the bones are held together by a disc of fibrocartilage. (para 4-8c(2))

14. A synovial joint is a joint in which the bones are able to move freely upon one another. (para 4-8d)

15. The major parts of a synovial joint are:

a. Bones.

b. Articular cartilages.

c. (1) Synovial membrane. (2) Synovial space. (3) Synovial fluid.

d. Capsule.

e. Ligaments.

f. Muscles. (para 4-9)

16. Synovial joints may be classified as follows:

a. Uni-axial--motion in one plane. (1) HInge joint. (2) Pivot joint.

b. Bi-axial--motion in two planes. Saddle joint.

c. Multi-axial--motion in all three planes. (1) Ball-and-socket joint. (2) Plane joint. (para 4-10)

17. The major subdivisions of the skeleton are the:

a. Axial skeleton--the central framework of the human body--including the skull, vertebral column, and thoracic cage.

b. Appendicular skeleton--skeletal elements of the upper and lower members. (paras 4-12, 4-13, 4-14)

18. The two major parts of a typical vertebra are the:

a. Vertebral body--drum-shape cylinder. Its function is to bear weight.

b. Neural arch--arch over posterior of the spinal cord. The neural arch has several processes. The processes are sites for attachment of trunk muscles and act as levers for trunk motions. (para 4-13a(1))

19. The regions of the vertebral column and the number of vertebrae in each are as follows:

a. Cervical (neck) region, 7.

b. Thoracic (chest) region, 12.

c. Lumbar (low back) region, 5.

d. Sacrum, fusion of 5.

e. Coccyx ("tail"), 3-4 together. (para 4-13a(2))

20. a. Intervertebral discs hold the bodies of adjacent vertebrae together, are fibrous rings with soft centers, allow adjacent vertebral bodies to move on one another, and are part of plane-type joints between vertebrae.

b. Ligaments are dense FCT structures extending from bone to bone (along the vertebral column from the base of the skull to the coccyx). (para 4-13a(3))

21. The thoracic (rib) cage consists of the sternum (manubrium, body, and xiphoid process), 12 pairs of ribs, and 12 thoracic vertebrae. The thoracic cage provides protection for vital organs within the thorax. It also allows the movements of breathing. (para 4-13b)

22. The two major subdivisions of the skull are as follows:

a. Cranium: Encases and protects brain.

b. Facial skeleton: Involved with beginning of digestive and respiratory tracts; encases and protects the special sense organs (eyes, ears, etc.). (para 4-13c)

23. PART

UPPER MEMBER

LOWER MEMBER

a. GIRDLE

PECTORAL GIRDLE

PELVIC GIRDLE

b. PROXIMAL SEGMENT HUMERUS FEMUR