Given below are the pathways for control of a body function by two hormones to maintain homeostasis. Identify the correct ones:
A: A decrease in blood calcium leads to secretion of parathyroid hormone by the parathyroid gland that causes an increase in blood calcium level; an increase in blood calcium level leads to secretion of thyrocalcitonin by thyroid gland that causes a decrease in blood calcium level.
B: A decrease in GFR blood flow/blood pressure causes release of rennin and formation of angiotensin II that causes vasodilation correcting GFR; an increase in blood flow to atria/blood pressure causes release of ANF that causes vasoconstriction.
C: A decrease in blood glucose leads to secretion of glucagon which retards the uptake of blood glucose by body cells; an increase in blood glucose leads to secretion of insulin that promotes the uptake of glucose by body cells.
1. Only A and B
2. Only A and C
3. Only B and C
4. A, B and C