1. It's cold and you have "goose bumps" on your forearm. Relate that to homeostasis for temperature regulation.

if you were a mammal with more fur, that would fluff up your fur for better insulation and less heat loss

2. If there were not enough iodine in the diet, explain how (and in what direction) that would affect the level of thyroid stimulating hormone from the pituitary.

low iodine would lead to low thyroxine (T3 and T4, i.e. thyroid hormone) and the lower negative feedback to the pituitary would increase TSH

3. "In an isotonic milieu like the blood stream, a red blood cell's shape remains unchanged." To make red blood cell ghosts, Gorter and Grendel Answer one of the following: (1) They moved the cells from an isotonic solution to what kind of solution? (2) What famous membrane transport process mediated the net influx of water into the cell?

hypotonic (distilled water), osmosis

4. "You can see the hydrophilic layers of the membrane and they are dark, while the hydrophobic layer is light." This is a very careless way of stating the appearance of a membrane in the electron microscope. Make part of this statement more scientifically accurate.

"dark" is electron dense because of staining with heavy metals, and "light" is the opposite

5. In addition to glycolipids and cholesterol, what is the major lipid constituent of the cell membrane?


6. If you wanted to record the current carried through a single nicotinic acetylcholine receptor, what technique would you use?

patch clamp, put electrode up to the channel but do not poke it into the cell

7. Based on a careful analysis of how a Wheatstone bridge went out of balance while an action potential went by, what fundamental conclusion did Cole and Curtis make?

that the conductance increased during the action potential

8. When Nernst assumed equilibrium, he assumed that the energies (say for potassium) in a two thermodynamic systems (say inside the cell vs outside the membrane) are equal. For each system (say inside the cell), there are two components, an electrical component and (what?)

a chemical component

9. Suppose, with a given set of permeabilities and the standard concentrations, the Goldman equation approximated the resting potential. What would you need to change to calculate the peak of the action potential from the Goldman equation?

increase sodium permeability

10. How do the cells that myelinate axons differ in the central vs. the peripheral nervous systems?

cns oligodendroglia myelinate a few axons while pns Schwann cells myelinate only one

11. For post-polio syndrome (worsening symptoms in middle age), according to a paper discussed in class, why is there (answer either) (1) a recovery after the initial infantile paralysis, or (2) the worsening symptoms in middle age?

spinal motor neurons sprout to connect to abandoned muscle fibers, these sprouts go away

12. Although Ramon y Cajal used Golgi's technique, and the two shared the Nobel Prize in 1906, only Ramon y Cajal's viewpoint required the existence of synaptic connections such as Nobelist Sherrington proposed. In what way did Ramon y Cajal's vs Golgi's viewpoints differ regarding this issue?

only Ramon y Cajal thought cells were separate entities that would need to signel to each other

13. Why did Sherrington refer to the spinal motor neuron as the "final common pathway in the integrative action of the nervous system?"

it can integrate EPSPs and IPSPs while the motor end plate is only excitatory

14. In contrast with the mechanism to terminate cholinergic transmission (involving acetylcholinesterase) what keeps norepinephrine or epinephrine from stimulating the receptor forever?


15. Why not just give dopamine to help patients with Parkinson's disease?

it does not cross the blood brain barrier

16. A portion of the parasympathetic output comes from the sacral portion of the spinal cord. What part of the central nervous system is the source for the rest of the parasympathetic output?


17. For nitric oxide (NO), answer EITHER (1) What cell does it come from? OR (2) What enzyme does it activate?

endothelial, guanylate cyclase

18. Why, in his Nobel prize winning work, did Sir Bernard Katz decrease the extracellular calcium in the neighborhood of the end plate?

to decrease vesicle release

19. What is the name of the band where there is myosin but not actin?

helle (lighter) H band

20. In addition to plasma free fatty acids and muscle triglyceride, name one caloric source of energy in muscle.

glucose (from plasma) and glycogen (in muscle)

21. What TWO locations are there calcium channels in a striated muscle cell?

t-tubules and sarcoplasmic reticulum

22. How did I get from the activation of myosin light chain kinase (MLCK) to a therapy to decrease blood pressure?

calcium channel blockers would relax arteriole smooth muscle because calcium is necessary to activate MLCK and it comes in from outside the cell through calcium channels

23. Using hemoglobin as an example, what is the quaternary structure of this protein?

two alpha and two beta subunits linked together

24. Under the influence of insulin, how can there be a rapid increase in the amount of glucose that can be transported into muscle and liver cells?

the GLUT4 transporters are at the ready in vesicles and moved to the plasmalemma

25. In order to regenerate NAD from NADH plus H+, what chemical is converted to what chemical (ANSWER BOTH) when glycolysis takes place under anaerobic conditions?

pyruvic acid into lactic acid

26. Under the influence of insulin, glucose is taken out of the blood stream into the liver, adipose tissue and (what other organ?).

skeletal muscle

27. What does an echocardiogram (ultrasound) show that an electrocardiogram does not?

you see the beating heart, the valves moving, the thickness of the walls

28. Why do the semilunar valves snap shut (and produce the second heart sound, "dub").

as ventricles relax, back pressure from the arteries is higher than the ventricular pressure

29. We identified which valve closures created the first and second "lub-dub" heart sounds. By contrast, I am asking you: Which valves open first (after the beginning of ventricular contraction)?

semilunar valves (that separate ventricles from arteries)

30. Parasympathetic and sympathetic portions of the autonomic nervous system affect heart rate, acting on the SA (and AV) nodes. What additional direct affect does the sympathetic nervous system have on the heart?

sympathetic NS increases myocardial contractility

31. When discussing the Frank-Starling law, I contrasted the situation (for cardiac muscle) with the situation (for striated muscle) where there is a drop off at greater length in the relative tension. However, for the Frank-Starling law, we do not plot relative tension as a function of percentage of resting length. Give me the X OR the Y for the Frank Starling law.

x-ventricular end-diastolic volume (ml), y-stroke volume (ml)

32. The sympathetic and parasympathetic nervous systems regulate heart rate and contractility and hence blood pressure. How is blood pressure monitored to achieve this autonomic homeostatic blood pressure control?

with mechanoreceptors in the aortic arch and carotid bodies via the medulla

33. Why does aspirin help to prevent a heart attack?

it inhibits clotting

34. The stress EKG ANSWER EITHER (1) What disorder is it used to diagnose? (2) How is the stress achieved? OR (3) What is the target pulse they try to get?

occluded coronary artery, treadmill or injection, 220 minus age

35. Why is the burning of fossil fuels expected to cause global warming?

atmospheric carbon dioxide acts like the glass in a green house

36. Approximatey, what is the partial pressure of carbon dioxide in the alveloi and in the pulmonary veins and in the systemic arteries (all the same) during normal tidal ventillation?

40 mm Hg

37. When carbon dioxide is moving from the blood to the alveoli, what happens to chloride and why?

it moves out of the red blood cell so that bicarbonate from the plasma can move into the red blood cell

38. Cystic fibrosis ANSWER EITHER (1) How do parents take care of the children? OR (2) Molecularly OR genetically, what is wrong?

percussion (thump the chest) for more productive coughing, chloride channel because of mutation in CFTR

39. "Diabetics' kidneys cannot pump glucose back into the bloodstream." False! Then why is there glucose in the urine of untreated diabetics?

they pump, but there is so much glucose that the pump saturates

40. Inulin clearance ANSWER EITHER (1) Rather than injecting inulin, there is a more convenient test involving (what?) substance that is already in the body. OR (2) What specific aspect of kidney function is being tested?

creatinine, glomerular filtration

41. Why do they serve Gatorade to runners during a marathon?

salt appetite because of salt loss through perspiration

42. Why would you prescribe Warfarin to a patient?

prevent any problem having to do with a blood clot (thrombus, embolism), for instance heart attack (coronary thrombosis)

43. "Carboxypeptidase is an exopeptidase." ANSWER EITHER (1) What specific function of carboxypeptidase gives it this name? OR (2) Why is it called an exopeptidase?

1-it cuts off the amino acid at the carboxy terminal of the peptide, 2- it cuts at the end, not in from the end

44. "The microsomal fraction gets the first crack at detoxifying anything in what you eat." ANSWER EITHER (1) What is the microsomal fraction? (2) Where was this microsomal fraction obtained? OR (3) How is it that absorbed food is delivered for the microsomal fraction to do its work?

1-the hepatocyte's smooth endoplasmic reticulum, 2-grinding up liver, 3-because of the hepatic portal vessel

45. Regarding the hormone leptin ANSWER EITHER (1) Where does it come from? OR (2) What structure does it affect?

adipose tissue, hypothalamus (arcuate nucleus)

46. Suprachiasmatic nucleus, paraventricular nucleus and arcuate nucleus are all part of what important part of the brain involved in motivation, among other things?


47. In terms of the uterus, what is happening during menstruation?

endometrium which had built up breaks down

48. How does the rhythm method of birth control work?

a 4-day window around the approximate time of ovulation when sperm and egg can be viable

49. An osteoclast contributes to the regulation of blood calcium ... Answer either (1) under the influence of what hormone? (2) how?

parathormone, secrete HCl to break down calcium phosphate and enzyme to break down collagen

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

51. "Perinatal testosterone treatment can masculinize a female rat." Describe the experiment and results demonstrating this regarding feeding behavior.

put a little testosterone under the skin of a newborn pup and the adult weight will be intermediate between female (250 g) and male (500 g)

52. Why would a transdermal patch be less likely than oral administration to create problems with estrogen replacement therapy?

via the oral route, it would affect receptors in the liver plus get converted to other forms in the liver

53. What does it mean when we describe arachidonic acid as "20:4?"

it is 20 carbons long and has 4 double bonds

54. Oh sure, incontinence and impotence are side effects of prostate surgery to be avoided. But there is a more fundamental reason that surgery is not performed as much as it used to be. What is this reason?

it does not increase survival

55. What divides to create identical twins?

the inner cell mass

56. "The purpose of meiosis is to establish genetic variability among the possible germ cells." If there were no crossing over, how many different combinations of chromosomes would there be in a man's sperm or a woman's eggs?

2 to the 23 power

57. After a neutrophil phagocytoses a bacterium, what does the cell do to destroy this bacterium?

merges the endosome with a lysosome

58. Why is it useful that fibrin has to be actively activated from its precursor, fibrinogen?

you would only want blood to clot where it needs to clot

59. There are some interesting differences in ABO blood groups vs. Rh factor antibodies. Answer either (1) Why would there be a bad reaction to the first type A transfusion into a B recipient? or (2) Why would an Rh- mother only have to worry (a lot!) about her further pregnancies after she has born an Rh+ baby?

there is already antibody, the IgG crosses the placenta

60. A B cell, whose job is to make a plasma cell to make antibodies, is already coated with antibodies (amazingly). ANSWER EITHER (1) What kind of antibody is it? OR (2) What is the particular function of these antibodies?

1-IgD, 2-receptors for antigens

61. How do helper T cells assist killer T cells in their mission to destroy lots of cells that have been infected by the identified pathogen?

via interleukin 2, they signal killer cells to proliferate

62. How did they learn which parts of the body project to which parts of the postcentral gyrus?

gently stimulate the gyrus in a patient under local anesthesia and ask where (s)he feels a tingle

63. For the fasciculus graciculus and the fasciculus cuneatus, say something about (1) ipsilateral vs contralateral, or (2) where, in the spinal cord, these tracts are located.

decussation to the contralateral side is in the medulla after the first synapse, dorsal columns

64. A neuron in the precentral gyrus (pyramidal system) makes its synapse onto what neuron?

the spinal motor neuron

65. Vagus nerve (cranial nerve X) and glossopharyngeal nerve (cranial nerve IX). What additional afferent nerve carries taste information from the tongue to the brain? (name OR number would suffice)

facial (VII)

66. Approximately how many G protein coupled receptors are there for human olfaction?

lots, 500-1000

67. The fluid pressure is transferred from the stirrup (stapes) ANSWER EITHER (1) to (name of the "inner ear drum?") OR (2) is released at (what other "window" facing the middle ear?)

oval window, round window

68. The audibility curve showed hearing threshold. Flipped over, it showed hearing sensitivity. ANSWER EITHER (10 What is on the X axis? OR (2) What is on the Y axis?

frequency (Hz or cycles per second), intensity in dynes per square centimeter or decibels

69. How does a tip link help the channel on the stereocilium?

this extracellular protein helps to pull open the mechanoreceptor as stereocilia bend and one stereocilium pulls at another

70. Nearsightedness ANSWER EITHER (1) What is the official term? OR (2) What kind of lens corrects this refractive disorder?

myopia, concave

71. Say something about the involvement of phosphodiesterase in visual transduction.

activated by alpha subunit of transducin, breaks down cGMP and so channel closes

72. Dark current along the length of the rod ANSWER EITHER (1) Why does it exist? OR (2) Under what circumstances does it stop?

sodium comes in in the outer segment and goes out in the inner segment, stops in the light

73. A cis to trans isomerization of what chromophore, (name that chromophore), a component of a G protein coupled receptor, is the only thing light actually does in visual transduction?

11-cis retinal (retinene) the aldehyde of vitamin A

74. Say something about why the macula (the area around the fovea) looks yellow when viewed through an ophthalmoscope.

carotenoids zeaxanthin and lutein block blue light to protect foveal cones

75. Why is there lutein in your vitamin pill?

this is one of the carotenoids in the macular pigments that protect

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last updated Nov 29, 2016