Ch. 6 Bones and Skeletal Tissues
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Problem 2
Sites of hematopoiesis include all but a. red marrow of spongy bone b. the heads of femur and humerus in adults c. medullary cavities in bones of infants d. medullary cavities in bones of a healthy adult.Problem 3
The organic portion of matrix is important in providing all but a. tensile strength b. hardness c. ability to resist stretch d. flexibility.Problem 4
Bone remodeling in adults is regulated and directed mainly by a. growth hormone b. thyroid hormones c. sex hormones d. mechanical stress e. PTH.Problem 6
Wolff's law is concerned with a. calcium homeostasis of the blood b. the shape of a bone being determined by mechanical stresses placed on it c. the electrical charge on bone surfaces.Problem 7
Formation of the bony callus in fracture repair is followed by a. hematoma formation b. fibrocartilaginous callus formation c. bone remodeling d. formation of granulation tissue.Problem 9
The disorder in which bones are porous and thin but bone composition is normal is a. osteomalacia b. osteoporosis c. Paget's disease.Problem 10
Describe in proper sequence the events of endochondral ossification in a long bone.Problem 11
A bone with approximately the same width, length, and height is most likely a. a long bone b. a short bone c. a flat bone d. an irregular bone.Problem 12
Osteocytes residing in lacunae of osteons of healthy compact bone are located quite a distance from the blood vessels in the central canals, yet they are well nourished. How can this be explained?Problem 13
As we grow, our long bones increase in diameter, but the thickness of the compact bone of the shaft remains relatively constant. Explain this phenomenon.Problem 14
Describe the process of new bone formation in an adult bone. Use the terms osteoid seam and calcification front in your discussion.Problem 15
a. Why are fractures most common in elderly individuals? b. Why are greenstick fractures most common in children?Problem 16
Yolanda is asked to review a bone slide that her professor has set up under the microscope. She sees concentric layers surrounding a central cavity. Is this bone section taken from the diaphysis or the epiphyseal plate of the specimen?Problem 17
Why do you think wheelchair-bound people with paralyzed lower limbs have thin, weak bones of the leg and thigh?Problem 19
Compare and contrast controls of bone remodeling exerted by hormones and by mechanical and gravitational forces, including the purpose of each control system and changes in bone architecture that might occur.Problem 20
Mrs. Abbruzzo brought her 4-year-old daughter to the doctor, complaining that she didn't 'look right.' The child's forehead was enlarged, her rib cage was knobby, and her lower limbs were bent and deformed. X rays revealed very thick epiphyseal plates. Mrs. Abbruzzo was advised to increase dietary amounts of vitamin D and milk and to get the girl outside to play in the sun. Considering the child's signs and symptoms, what disease do you think she has? Explain the doctor's instructions.Problem 21
What would a long bone look like at the end of adolescence if bone remodeling did not occur?Problem 22
Noah Beckenstein went to weight-lifting camp in the summer between seventh and eighth grade. He noticed that the camp trainer put tremendous pressure on him and his friends to improve their strength. After an especially vigorous workout, Noah's arm felt extremely sore and weak around the elbow. He went to the camp doctor, who took X rays and then told him that the injury was serious, for the 'end of his upper arm bone was starting to twist off.' What had happened? Could the same thing happen to Noah's 23-year-old sister, Karen, who was also starting a program of weight lifting? Why or why not?
