One effect of aging on the skeletal system is
A. decreased collagen fibers.
B. Decreased bone matrix and decreased collagen fibers are effects of aging.
C. decreased bone matrix.
D. increased bone density.
E. increased elastic fibers.
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Question 2) Which of the following statements regarding PTH (parathyroid hormone) is true?
A. PTH causes increased Na+ reabsorption in the kidneys.
B. PTH causes increased reabsorption of Ca2+ in the kidneys.
C. PTH causes increased loss of Ca2+ from the kidneys.
D. PTH causes decreased uptake of Ca2+ from the small intestine.
E. PTH causes decreased vitamin D formation in the kidneys.
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Question 3) What chemical causes an increase in the blood calcium level?
A. growth hormone
B. vitamin D
C. sex hormones
D. calcitonin
E. parathyroid hormone
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Question 4) Sally has elevated levels of blood calcium. What chemical would you expect to find in high levels in response to this condition?
A. sex hormones
B. parathyroid hormone
C. growth hormone
D. calcitonin
E. vitamin D
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Question 5) Parathyroid hormone (PTH) causes
A. increased RANKL and decreased OPG.
B. PTH has no effect on RANKL and OPG.
C. increased RANKL and increased OPG.
D. decreased RANKL and decreased OPG.
E. decreased RANKL and increased OPG.
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Question 6) Osteoclast activity would decrease when ________ levels are elevated.
A. vitamin C.
B. growth hormone.
C. calcitonin.
D. parathyroid hormone.
E. vitamin D.
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Question 7) Which of the following statements regarding calcium homeostasis is true?
A. When blood calcium levels are too low, osteoclast activity increases.
B. Parathyroid hormone increases calcium loss from the kidney.
C. Increased osteoblast activity increases blood calcium levels.
D. Calcitonin elevates blood calcium levels.
E. Parathyroid hormone inhibits osteoclast activity.
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Question 8) Which of the following is NOT an effect of parathyroid hormone (PTH)?
A. increased Ca2+ uptake by the small intestine
B. increased vitamin D formation in the kidneys
C. increased Ca2+ reabsorption by the kidneys
D. decreased Ca2+ loss by the kidneys
E. All of these are effects of PTH.
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Question 9) Sam was a 60 year old man. As a result of picking up a heavy object he fractured the radius and ulna of his right arm.
X-rays indicated that he had severe osteoporosis. His blood calcium levels were above normal and the pathologist found cancer cells that produced a hormone-like substance. That substance was most likely
A. thyroid hormone.
B. calcitonin.
C. growth hormone.
D. parathyroid hormone.
E. vitamin D.
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Question 10) Osteoclast activity is increased by
A. vitamin C.
B. parathyroid hormone.
C. calcitonin.
D. vitamin D.
E. growth hormone.
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