The Skeletal System

1. 5 The Skeletal System 0

2. 1. Which of the following is a function of the skeletal system? • Production of red blood cells • Regulation of body temperature • Removal of metabolic waste • Synthesis of vitamin D

3. 1. Which of the following is a function of the skeletal system? Answer: a. Production of red blood cells Explanation: The red bone marrow of the skeletal system produces red blood cells, white blood cells, and platelets. The skeletal system does not regulate body temperature, remove metabolic waste, or synthesize vitamin D.

4. 2. Which type of bone tissue forms the superficial layer of all bones? • Compact • Spongy • Red bone marrow • Yellow bone marrow

5. 2. Which type of bone tissue forms the superficial layer of all bones? Answer: a. Compact Explanation: Spongy bone is on the inside of bones, while compact bone covers all bone surfaces. Bone marrow is the innermost layer.

6. 3. The membrane around the outside of all bones is the _____. • pericardium • parietal pleura • mucous • periosteum

7. 3. The membrane around the outside of all bones is the _____. Answer: d. periosteum Explanation: The pericardium surrounds the heart, the parietal pleurae line the pleural cavities, and mucous membranes line cavities open to the exterior. The periosteum surrounds the bones

8. 4. The nonliving portion of the bone is made mostly of _____. • polysaccharides, sodium, and sugars • keratin, sodium, and sebum • collagen fibers, calcium, and phosphates • red bone marrow, yellow bone marrow, and spongy bone

9. 4. The nonliving portion of the bone is made mostly of _____. Answer: c. collagen fibers, calcium, and phosphates Explanation: Calcium and phosphate salts crystallize on collagen fibers. This matrix surrounds the cells (remember, connective tissue contains cells surrounded by a noncellular matrix).

10. 5. Bone-forming cells are called _____, while cells that dissolve bone, releasing calcium and phosphorus, are _____. • osteoclasts; osteoblasts • osteocytes; osteoclasts • osteoblasts; osteoclasts • osteoclasts; osteocytes

11. 5. Bone-forming cells are called _____, while cells that dissolve bone, releasing calcium and phosphorus, are _____. Answer: c. osteoblasts; osteoclasts Explanation: Osteoblasts deposit bony matrix, while osteoclasts dissolve bony material. osteo  bone and blast  beginning or bud.

12. 6. Which hormone(s) stimulate(s) the epiphyseal plate (growth plate)? • Growth hormone • Thyroid hormone • Sex hormones • All of the above

13. 6. Which hormone(s) stimulate(s) the epiphyseal plate (growth plate)? Answer: d. All of the above Explanation: Growth hormone, thyroid hormone, and sex hormones all cause long bone growth by stimulating the epiphyseal plate, also known as the growth plate.

14. 7. When does bone remodeling occur? • until teenage years • when tiny cracks in bones occur after a jump from a high place • bone remodeling is a lifelong process • both B and C

15. 7. When does bone remodeling occur? Answer: d. both B and C Explanation: Even after reaching our full height, we continue to undergo a lifelong process of bone deposition and breakdown called remodeling. Bone remodeling keeps bones strong by repairing tiny cracks in bones, such as might occur if you jump from a high place.

16. 8. When blood calcium levels are too low, the hormone _____ is released, which stimulates osteoclasts to break down bone and release calcium into the blood. • calcitonin • growth hormone • estrogen • parathyroid hormone

17. 8. When blood calcium levels are too low, the hormone _____ is released, which stimulates osteoclasts to break down bone and release calcium into the blood. Answer: d. parathyroid hormone Explanation: Parathyroid hormone increases blood calcium levels by stimulating the activity of osteoclasts. Calcitonin lowers blood calcium levels and stimulates osteoblasts. Growth hormone and sex hormones (estrogen in women) are involved in bone growth.

18. 9. Which of the following is part of the pectoral girdle? • Femur • Pelvis • Scapula • Skull

19. 9. Which of the following is part of the pectoral girdle? Answer: c. Scapula Explanation: The pectoral girdle is the shoulder, and includes the scapula and the clavicle. Femur is the upper leg, pelvis is part of the pelvis girdle, and skull is in the axial skeleton.

20. 10. Which one is NOT a joint? • Fibrous • Cartilaginous • Synovial • All of the above are joints

21. 10. Which one is NOT a joint? Answer: d. All of the above are joints Explanation: Joints are the places where bones meet. They can be classified as fibrous, cartilaginous, or synovial, depending on their components and structure.

22. 11. The sutures of the skull are examples of a _____ joint. • synovial • cartilaginous • fibrous • hyaline

23. 11. The sutures of the skull are examples of a ______ joint. Answer: c. fibrous Explanation: The bones of the skull are held together tightly by dense fibrous connective tissue. In fact, the sutures can actually move ever so slightly. This ability is fortunate, because the movements serve as a shock absorber when you hit your head

24. 12. Movement of a body part toward the body midline is called _____. • rotation • supination • adduction • circumduction

25. 12. Movement of a body part toward the body midline is called _____. Answer: c. adduction Explanation: Adduction is the movement of a body part toward the body midline. Rotation is the movement of a body part around its own axis, circumduction is a movement of a body part in a wide circle following a cone. Supination is the rotation of the forearm so that the palm faces up.

26. 13. Fontanels are found _____. • in the adult skull • at the base of the occipital bone • in infant skulls • between vertebrae

27. 13. Fontanels are found _____. Answer: c. in infant skulls Explanation: Fontanels are soft membranes found between the cranial bones of fetuses and infants. They function to accommodate childbirth and the rapid growth of the brain in the first two years of life.

28. 14. Which disease is an autoimmune disease? • Osteoarthritis • Scoliosis • Rheumatoid arthritis • Rickets

29. 14. Which disease is an autoimmune disease? Answer: c. Rheumatoid arthritis Explanation: Osteoarthritis is a degeneration of the joint surfaces due to wear and tear, scoliosis is an abnormal lateral curvature of the spine, and rickets is a softening of the bones caused by deficiencies in vitamin D.