Parathyroid hormone functions to increase calcium ion levels in blood. If its secretion is regulated through negative feedback, under which conditions would this hormone normally be released?
A. Parathyroid hormone secretion increases in the morning and decreases in the afternoon.
B. Parathyroid hormone secretion occurs when blood calcium levels are too high.
C. Parathyroid secretion is constant to maintain blood calcium levels.
D. Parathyroid hormone secretion occurs when blood calcium levels are too low.
Answer: D
You might also like to view...
Intercalated discs couple ________ cells both mechanically and electrically.
A. skeletal muscle B. smooth muscle C. myocardial D. both myocardial and skeletal muscle
During starvation, steroid hormones trigger the transcription of genes for lipid metabolism in their target cells. This would be an example of control by
A) positive feedback. B) repressors. C) alternative splicing. D) negative feedback. E) inducers.
The common pathway of coagulation begins with the
A) activation of a clotting factor that converts fibrinogen to fibrin. B) sticking of platelets to damaged tissue. C) activation of a proenzyme exposed to collagen. D) release of tissue factor by a damaged endothelium. E) activating of a clotting factor that converts prothrombin to thrombin.
Indicate the three protein fiber types found in fibrous connective tissue
What will be an ideal response?