1. A person under chronic stress has elevated levels of cortisol and increased insulin
a) Explain the regulatory pathway that leads to increased blood cortisol.
Include the second messenger pathway for cortisol production. [6 marks]
b) Explain why this person also has increased levels of insulin [3 marks –
intracellular pathways not required]
2. Blood calcium levels are maintained in a very small range. Discuss the coordinated
action of Vitamin D and parathyroid hormone in regulating blood calcium.
Provide details on production, control and mechanisms of action for each of these
hormones. [ 5 marks each = 10 marks total]
1. The cell type that is specialized to communicate with other cells and control their
A. muscle cells.
B. epithilelial cells.
C. glial cells
D. nerve cells
2. The concept of homeostasis:
A. includes the a feed back signal
B. refers to maintaining physiological functions in a stable condition.
C. refers only to regulation of body temperature
D. A & B
E. A, B & C
3. If blood pressure increases then the homeostatic response would be expected to
A. decrease blood pressure
B. increase blood pressure
C. leave blood pressure unchanged.
D. change the set point for blood pressure
4. Which one of the following is the correct sequence for a reflex arc?
A. stimulus, effector, efferent pathway, integrating center, afferent pathway, receptor
B. stimulus, receptor, efferent pathway, integrating center, afferent pathway, effector
C. stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector
D. stimulus, effector, afferent pathway, integrating center, efferent pathway, receptor
5. The hormone insulin enhances the transport of glucose into most of the body's cells. Its
secretion is controlled by a negative-feedback system between the concentration of glucose in the blood and the cells that secrete insulin. Which of the following statements
is most likely to be correct?
A. A decrease in blood glucose concentration will stimulate insulin secretion, which
will in turn lower the blood glucose concentration still further.
B. An increase in blood glucose concentration will stimulate insulin secretion, which
will in turn lower the blood glucose concentration.
C. A decrease in blood glucose concentration will stimulate insulin secretion, which
will in turn increase the blood glucose concentration.
D. An increase in blood glucose concentration will stimulate insulin secretion, which
will in turn increase the blood glucose concentration still further.
E. None of the choices are correct.
6. Heart rate is affected by the release of epinephrine from the adrenal medulla into the
bloodstream. This is an example of
A. endocrine control.
B. exocrine control.
C. paracrine control.
D. direct neural control.
E. none of the choices are correct.
7. Which of the following statements about the Na,K pump is true?
A. It transports K+ out of cells and Na+ into cells.
B. It binds to and hydrolyzes ATP.
C. It is usually inactive in all cells.
D. It transports Na+ and K+ in a 1:1 ratio.
8. Receptors for intercellular messengers are most commonly
A. peripheral membrane proteins.
B. integral membrane proteins.
C. specialized phospholipids within the membrane.
D. nucleic acids.
9. Which of the following statements applies to autocrine regulation?
A. Chemical regulators are released directly into blood vessels.
B. Chemical regulators released by cells affect cells in the vicinity of the
C. Chemical regulators affect the same cell that produced it.
D. Chemical regulators reach their site of action through a duct.
E. Chemical regulators are continuously released in constant amounts by the cell
10. Oxytocin is a peptide hormone that causes the smooth muscle of the uterus to
contract, but it has no effect on the smooth muscle cells of the small intestine. This
difference in responsiveness exists because
A. oxytocin is inactivated prior to reaching the smooth muscle cells of the intestine. B. intestinal smooth muscle cells do not contain the proper second messenger
C. uterine smooth muscle cells contain specific receptors for oxytocin.
D. oxytocin is able to cross the plasma membrane of uterine cells but not intestinal
E. oxytocin is not delivered by the circulatory system to intestinal cells.
11. The median eminence of the hypothalamus is
A. the site of synthesis of ACTH.