1. After a peptide is clipped out of the prohormone, what holds the two resulting chains of insulin together?

disulfide bonds

2. A person with type 1 diabetes has his blood glucose pretty much under control. Why does he need to test his blood rather than his urine to precisely control his levels by insulin injection.

glucose only shows up in the urine when it is really high in the blood

3. Adipose tissue, answer one (1) Insulin stimulates uptake of (you need only state one of the two)? OR (2) Inside the cell, it is converted into (you need only list one of the two)?

glucose and fatty acids, glucose to glycerol then fatty acids added to make triglycerides

4. What is the unique function of the ATP generated from glucose metabolism in the beta cell of the islets of Langerhans?

ligand to close potassium channels to depolarize the cell for calcium entry and insulin exocytosis

5. In contrast with the insulin receptor, an RTK (receptor tyrosine kinase), the glucagon receptor is a (what?).

G protein coupled receptor

6. Cyclic AMP binds to an inhibitory subunit. When a cell is activated by glucagon, what enzyme gets activated as a result?

protein kinase (PKA=A-kinase)

7. Chordae tendineae, answer either (1) What do they connect to? OR (2) Why are they important?

from ventricular papillary muscles to tricuspid and bicuspid (AV) valves, to reinforce valves so that ventricular pressure does not blow them out into the atria

8. A cell lines the capillary. Answer either (1) What is this cell type called? OR (2) What specialization does this cell exhibit if it is called "fenestrated?"

endothelial, has windows (holes)

9. How is it that the electrical activity of the heart can be recorded from as far away as the extremities?

there is virtually no resistance in the extracellular fluid between the heart and the extremities, also a lot of cells in the heart function in synchrony

10. Why would alternating muscle contraction and relaxation increase venous return.

muscle contraction would squeese the vein and push blood past the next one-way valve

11. In addition to the sympathetic nervous system and precapillary sphincters, what mechanism restricts blood flow to the extremities in times of stress?

arteriovenous anastomoses

12. The beginning of ventricular contraction is referred to as "isovolumetric." What event ends that phase where the ventricle contracts without the volume of blood changing?

the opening of the semilunar valves

13. The length-tension curve for striated muscle differs significantly (and thankfully) from the Frank-Starling law. For either the (1) "percentage resting length" axis or for the (2) "relative tension" axis, identify the corresponding axes for the Frank Starling law.

ventricular end diastolic volume, stroke volume

14. For either (1) cuff pressure above the patient's systolic pressure, OR for (2) cuff pressure below the diastolic pressure, say why no sounds are heard in the bracheal artery.

those Korotkoff sounds were only during turbulent blood flow

15. Both parasympathetic and sympathetic nervous systems affect SA and AV nodes. In addition, what other direct affect does the sympathetic nervous system have in the heart?

sympathetic nervous system increases ventricular contractility

16. Name one of the specialized sets of fibers that speeds the action potential from the AV node to the ventricular myocardium especially in the apex of the heart.

atrioventricular bundle (of His), right and left bundle branches, Purkinje fibers

17. Re-entry of excitation - Why might myocardial cells have an action potential that occurs too early, i.e. before the next heart beat that originates from the SA node?

an action potential going from cell to cell around an area with non-conducting tissue resulting from damage would arrive at cells that are no nolger refractory sooner than the next SA trigger would arrive

18. "How the sympathetic nervous system opens the trachea is different from how an alpha adrenergic agonist like Neosynephrine causes vasoconstriction in the case of nasal congestion." Elaborate.

by relaxing smooth muscle, it opens airways while it causes vasoconstriction by constricting smooth muscle in nasal passages

19. Give a surface area explanation for why it is more work for someone with emphysema to breathe.

because alveoli merge, there are fewer and they are bigger, less surface area, so person has to breathe a lot more to get the same air exchange

20. The partial pressure of oxygen in alveoli is much lower than in the inspired air. Why?

water and carbon dioxide, virtually zero in inspired air, is much higher in alveoli, also not all the air exchanges

21. What would happen to your breathing if all the nerves to the diaphragm and intercostal muscles were severed?

it would cease

22. Why do chemoreceptors in the medulla react more to high carbon dioxide than those of the carotid and aortic bodies?

there are no buffers in the cerebrospinal fluid

23. What development occurs right around the normal time of birth that facilitates breathing?

type 2 alveolar cells mature and surfactant secretion begins

24. What would happen if the air pressure in the intrapleural space reached equilibrium with atmospheric pressure?

the lung would collapse (pneumothorax)

25. Uric acid, answer one of the following. (1) Why is it useful for some animals to use uric acid rather than urea for nitrogen elimination? OR (2) Why is it an oversimplification to claim that uric acid in joints causes the pain of gout?

conserves water, it is the inflammation (prostaglandins) caused by the uric acid that hurts

26. What is the geometry of the second capillary bed in the nephron?

the vasa recta wraps around the loop of Henle, in along the descending loop and out along the ascending loop

27. In addition to fenestrated endothelium, what structural specialization contributes to glomerular filtration?

pedicels of podocytes make a sieve

28. "In the ascending limb, sodium is actively transported, chloride follows passively but the ascending limb is impermeable to water." Why is this ultimately useful in water resorption?

by making the interstitial fluid hypertonic, the aquaporins in the collecting duct can bring water out of the urine

29. What would be the cause of death of a rat whose adrenal glands had just been removed and returned to its cage with rat chow and water available all the time?

salt loss

30. "During this heat wave, drink plenty of fluids, but limit your intake of alcohol." Why this latter tidbit of advice?

alcohol's inhibition of ADH would mean water loss through the kidneys

31. We discussed many different blood vessels in the nephron. Which regulates the angiotensin system?

afferent arteriole

32. "Digestion of starch that starts in the mouth is of little value." Why did I say that?

amylase action is terminated by the stomach's pepsin and HCl

33. Why is it useful that the chief cell produces pepsinogen rather than pepsin?

so it does not digest itself

34. What is the source of material that neutralizes acidity as stomach contents move to the small intestine?

bicarbonate comes from the pancreas

35. CyclicAMP signaling is important in water absorption in the intestine. What bacterial toxin can disrupt this cAMP-dependent water resorption?

cholera toxin

36. In addition to individual amino acids, what products of proteolytic enzymes are transported across the apical surface of the intestinal epithelium?

dipeptides and tripeptides

37. Bile pigments result from the recycling of what kind of CELL?

red blood cells

38. Regarding oxytocin and ADH, the portal system connecting the hypothalamus to the pituitary is not utilized. Elaborate.

neurosecretions from axon terminals in the posterior pituitary, cell bodies in the hypothalamus

39. Give the abbreviations of the two gonadotropins from the anterior pituitary.

FSH & LH

40. A cancer in the pituitary cells that would produce growth hormone would produce what syndrome in the adult?

acromegaly

41. Cretinism is from shortage of what hormone at what phase in life?

thyroxine neonatally

42. ACTH is a peptide produced by being cut out of a larger precursor named (what?).

POMC=pro-opiomelanocortin

43. In terms of homeostasis (negative feedback control) what circumstances lead to the initial output of FSH from the pituitary.

low estrogen and progesterone meams no negative feedback

44. In addition to initiating the formation of the corpus luteum, a burst of LH does what?

leads to ovulation

45. How is it that "the pill" does not prevent menstruation?

progesterone (and estrogen) stimulate buildup of the endometrium, dud pills at the end allow breakdown

46. Which hormone allows calcium to be borrowed from bone to increase blood calcium?

parathormone (PTH)

47. Sunlight, 25-Hydroxylase, and 1-alpha-Hydroxylase provide what to the blood stream? (A specific or a general name would be acceptable.)

"vitamin D" = 1,25-Dihydroxy vitamin D3

48. On what molecule AND where (in relation to exons and introns) does the steroid hormone - steroid hormone receptor complex bind?

the response element is upstream of the protein's coding sequence on the DNA

49. "You might think that 5-year-old boys have different behavior than girls of the same age because of circulating testosterone levels." What is the more accurate statement about the cause of behavior differences at that age?

neonatal testosterone organizes the male brain, then there is very little testosterone until puberty

50. To mediate the effects of testosterone in males, aromatase converts it to what hormone that is more commonly associated with females?

estradiol-17beta (estrogen)

Last modified 11/2/2012

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