BackWhat is the major function of bone cells found in lacunae?
The vitamins essential for normal adult bone maintenance and repair are:
(a) A and E
(b) C and D3
(c) B and E
(d) B complex and K
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
While playing on her swing set, 10-year-old Sally falls and breaks her right leg. At the emergency room, the doctor tells her parents that the proximal end of the tibia where the epiphysis meets the diaphysis is fractured. The fracture is properly set and eventually heals. During a routine physical when she is 18, Sally learns that her right leg is 2 cm shorter than her left, probably because of her accident. What might account for this difference?
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?
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.
(a) During what period of life does skeletal mass increase dramatically? Begin to decline?
(b) Why are fractures most common in elderly individuals?
(c) Why are greenstick fractures most common in children?
Deborah, a 75-year-old woman, stumbled slightly while walking, then felt a terrible pain in her left hip. At the hospital, X-ray images revealed that the hip was broken. Also, the compact bone and spongy bone throughout her spine were very thin. What was her probable condition?