6. Bones & Skeletal Tissue

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.

Describe the process of new bone formation in an adult bone. Use the terms osteoid seam and calcification front in your discussion.

a. Why are fractures most common in elderly individuals?b. Why are greenstick fractures most common in children?

Why do you think wheelchair-bound people with paralyzed lower limbs have thin, weak bones of the leg and thigh?

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.

What would a long bone look like at the end of adolescence if bone remodeling did not occur?

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?

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?

Multiple ChoiceMore than one choice may apply. osteocyte.

Multiple ChoiceMore than one choice may apply.Which of the following would you expect to be prominent in osteoclasts?a. Golgi apparatusb. Lysosomesc. Microfilamentsd. Exocytosis

Exposure to optimum amounts of sunlight is necessary for proper bone maintenance and growth in children. (a) What does sunlight do to promote bone maintenance and growth?

Exposure to optimum amounts of sunlight is necessary for proper bone maintenance and growth in children. (b) If a child lives in an area where exposure to sunlight is rare because of pollution or overcast skies, what can be done to minimize impaired maintenance and growth of bone?

The presence of an epiphyseal line indicates (a) epiphyseal growth has ended, (b) epiphyseal growth is just beginning, (c) growth of bone diameter is just beginning, (d) the bone is fractured at the location, (e) no particular event.

The hormones that coordinate the storage, absorption, and excretion of calcium ions are (a) growth hormone and thyroxine, (b) calcitonin and parathyroid hormone, (c) calcitriol and cholecalciferol, (d) estrogens and androgens.

What is the primary difference between endochondral ossification and intramembranous ossification?