1. "It's cold and your hands are cold and "clammy." How does this help in temperature homeostasis?

peripheral vasoconstriction decreases heat loss

2. "Digestion gives us an excellent example of homeostasis (regulation): if we eat more calories than we burn, we gain weight, and if we eat less, we lose weight, and really very few people gain or lose weight rapidly. We do not lose calories in the feces or in the urine." How does the situation for an untreated diabetic present an exception to this last statement?

glucose is lost in the urine

3. There is a portal systm for hormones. Answer either (1) Where does it come from? OR (2) Where does it go to?

hypothalamus, anterior pituitary

4. What is it that makes the interior of the cell's membrane hydrophobic?

the fatty acid (acyl) tails of the membrane phospholipids

5. Why do you need channel or pump proteins to move ions like sodium and potassium across the cell membrane?

because of the hydrophobicity of the inside of the membrane (high resistance of membrane)

6. In a signal transduction cascade involving phospholapase C, what is released from the smooth endoplasmic reticulum in response to stimulation by a hormone?

calcium ions

7. "The resting potential is a potassium-based battery." Whose equation quantifies this battery?

the Nernst equation

8. Biologists use model organisms that are ideal for their specific studies. What was it about the squid that made it ideal for studying axonal action potentials?

since invertebrates do not have myelin, the giant axons squids have are easy to study

9. Why is the component for chloride reversed (relative to those of sodium and potassium) in the Goldman equation?

chloride is an anion

10. At any junction, the sum of currents is zero, and the sum of voltages around any loop is zero. Whose laws are those?

law of Kirchoff

11. Why do survivors of polio often have spindly calves?

peripheral nerve degeneration removes trophic influence on muscle

12. In the membrane lecture, the nicotinic channel was shown as open or closed. Describe how inactivation in the sodium channel looks different from that closed channel.

stopper on the N-terminus of the channel protein plugs the channel from inside the membrane

13. What is the difference between how a spinal neuron vs a muscle fiber reacts to neural input that led Sherrington to refer to the spinal motor neuron as "the final common pathway for the integrative action of the nervous system?"

neuron can be excited and inhibited but muscle cell can only be excited

14. "'Vagus stuff' slows the heart." What major subdivision of the autonomic nervous system sends 'vagus-stuff' to the heart?

parasympathetic (cranio-sacral)

15. ANSWER EITHER (1) Exactly what must be destroyed when you superheat the tomatoes and the mason jars when you are "canning" the tomatoes? OR (2) If you don't, what property of the bacteria allow them to grow?

endospores of Clostridium botulinum, they are anaerobic

16. Adrenergic transmission is terminated by re-uptake of the transmitter into the synaptic terminal. By contrast, how is cholinergic transmission terminated?

acetylcholine is broken down by acetylcholinesterase

17. ANSWER EITHER (1) Why does it make sense that monamine oxidase inhibitors would serve as antidepressants? OR (2) How does caffeine have its stimulatory effect?

both by potentiating adrenergic transmission (1) preventing norepinephrine breakdown (2) by inhibiting breakdown of cAMP by PDE

18. ANSWER EITHER (1) For what ailment would a doctor prescribe a beta-1 blocker? OR (2) Say something about the mechanism of action of such a drug.

hypertension, blocks sympathetic input to heart, lowering heart rate and contractility

19. What does an increase in sympathetic nervous system output do to arterioles feeding the skeletal muscles?

hyperemia = increased blood flow

20. Why is it harder to start a chin-up from all the way down than from halfway up?

there is less actin - myosin overlap

21. What does the binding of calcium ions to troponin do to facilitate the sliding filaments?

pulls tropomyosin off of actin's binding sites for myosin

22. During heavy exercise, what is the predominant source of energy in muscle?

muscle glycogen

23. What is the significance of varicosities in smooth muscle?

varicosities are the sites of transmitter release from the autonomic nerves

24. A triglyceride is made up of 3 fatty acids linked to (what?) with ester bonds.

glycerol

25. "Much less ATP is generated when metabolism is anaerobic." ANSWER EITHER (1) How many ATPs (net) per glucose? OR (2) In what branch of the metabolic pathway?

two, glycolysis

26. Where, in the metabolic pathway, are fatty acids used for energy?

chopped down 2 carbons at a time they feed to acetyl co-a then to the Krebs cycle

27. Say something about how the pro-hormone insulin is processed to form the final product, the hormone insulin.

a peptide is chopped out of the middle and discarded and two end peptides are linked by two disulfide bonds

28. GLUT2 allows glucose to be transported into a beta cell. How is this glucose monitored to determine if the beta cell should secrete insulin?

metabolism makes ATP, K+ channels close, the cell depolarizes, Ca2+ comes in and vesicles are released

29. How does cAMP activate protein kinase A?

it removes as inhibitory subunit

30. Why do the tricuspid and bicuspid (mitral) valves, the atrio-ventricular valves, snap shut?

when ventricles contract, ventricular pressure is higher than atrial pressure

31. Name ONE of the locations where there are baroreceptors to regulate blood pressure through the autonomic nervous system.

carotid sinus and aortic arch

32. What happens to the membrane potential of a pacemaker cell during diastole?

it depolarizes

33. Why don't you expect non-steroidal anti-inflammatory drugs such as ibuprophen to decrease inflammation in the bronchi (for treatment of asthma)?

the NSAIDS are anti-prostaglandin drugs and you need anti-leukotriene drugs like singulair

34. There is a greatly decreased surface area for gas exchange in the alveoli in what lung disease?

emphysema

35. Why would a premature infant have difficulty breathing?

too much surface tension of water in alveoli because type 2 alveolar cells have not matured and there is no surfactant

36. Why is pH in the medulla oblongata more important than pH in aortic and carotid bodies in controlling breathing?

there are no protein or cell surface buffers in cerebrospinal fluid because of the blood brain barrier

37. What happens to the Humboldt current during el Nino?

the upwelling of nutrients off the coast of Peru is interrupted (and the normally cool water is warmer) and the climate changes

38. In addition to fenestrated capillaries, what other cellular specialization allows for glomerular filtration?

foot processes (pedicels) of podocytes

39. Regarding the hormone involved in salt resorption from the ascending loop of Henle ANSWER EITHER (1) What gland does it come from? (be specific) OR (2) What type of molecule is it?

adrenal cortex, steroid

40. Why would starch eventually taste sweet if you kept it in your mouth?

salivary amylase would break glucose polymer into monomers

41. The pH optimum for trypsin is about 9. What is the pH optimum for pepsin?

about 2

42. In digestion, where do dipeptidases and tripeptidases function?

inside the intestinal epithelial cell

43. Where are the cell bodies for the neurosecretion from the posterior pituitary?

hypothalamus (supraoptic and paraventricular nucleus)

44. In addition to oxytocin, what pituitary hormone affects the mammary gland?

prolactin

45. A surge in a hormone (from where?) triggers ovulation.

anterior pituitary

46. Why would women taking the birth control pill still experience menstruation?

the steroids cause the build-up of the endometrium, and the lack of steroids in the last few pills allow for breakdown

47. Both calcitonin and parathyroid hormone regulate blood levels of calcium ions by influencing gut, kidneys and (what other location?).

bone

48. To function, testosterone is converted ANSWER EITHER (1) by what enzyme (name ONE)? OR (2) to what molecule (name ONE)?

5alpha-reductase, aromatase, 5alphaDHT, estradiol-17beta

49. A receptor bound to triiodothyroxine dimerizes with a receptor bound (to what?) to activate the hormone response element to transcribe genes activated by thyroid hormone.

9-cis-retinoic acid

50. What is the precursor for prostaglandins and leukotrienes?

arachidonic acid, 20:4, a polyunsaturated fatty acid

51. "Every cell in your body has all the same genes (except for gametes) and hormones, etc. regulate which genes are expressed." Why did I say "except for gametes?"

they are haploid, they only have half the genes

52. When are all the primary oocytes formed in the human?

by the time of birth

53. In a tubal ligation, ANSWER EITHER (1) What is ligated? OR (2) Why?

fallopian (uterine) tube, for sterility

54. In the early days, why was stem cell research in humans politically controversial?

it involved the creation and destruction of embryos

55. Why are the techniques of amniocentesis and chorionic villus biopsy used?

to screen for birth defects

56. How is extravasation related to chemotaxis in a phagocytic white blood cell?

to be attracted by chemical signals to the site of injury, the cell first has to slither out between endothelial cells

57. List at least one type of white blood cell that is not a polymorphonuclear granulocyte

monocyte, B-lymphocyte, T-lymphocyte

58. An Rh negative mother has an Rh positive baby. Why would they treat her with antibodies against Rh positive?

passive immunity would prevent her from mounting active immunity, so it is safe to have another baby who might be Rh positive

59. Even before a B lymphocyte has formed a clone of plasma and memory cells responsive to a particular antigen, that antigen binds to (what?) on the surface of the B cell.

a B cell receptor (IgD)

60. A killer T cell hooks up with and destroys a cell infected with virus using the antigen for identification plus (state ONE of the two communicating molecules).

class-1 MHC molecule on the infected cell and CD8 coreceptor on the killer T cell

61. Bradykinin is used in what sensory system?

somatosensory nociceptors

62. A touch receptor in the foot ANSWER EITHER (1) has its cell body (where?) OR (2) makes its first synapse (where?).

dorsal root ganglion (right outside spinal cord), medulla

63. Where is the decussation (cross-over from the ipsilateral to the contralateral side) for the spinothalamic (anterolateral) system?

at the same level as the point of entry

64. "The thalamus is a relay station for incoming sensory and outgoing motor information." And yet, the corticospinal tract does not make a synapse in the the thalamus. In what way, then, is the thalamus a relay in the motor system?

it relays the output of the extrapyramidal system (the basal ganglia)

65. What is PTC (phenyothiocarbamide)?

a stimulus that is bitter to TT and Tt genotypes but homozygous recessive tt people are taste blind to it

66. Taste receptors make synapses with three nerves that go to the gustatory nucleus in the medulla. Two of the nerves are the vagus (X) and the glossopharyngial (IX). What is the third?

facial (VII)

67. A channel opens in the stereocilia of the auditory receptor cell. What ion flows AND in what direction?

potassium, into the cell

68. ANSWER EITHER (1) Why would Bekesy's data seem at first to contradict Helmholtz's place theory? OR (2) How did he rationalize that the place theory still applied?

localization on the basilar membrane was to0 crude, but lateral inhibition sharpened the tuning in neural processing on the way to the brain

69. What frequency of sound do insectivorous bats use to find their insect prey?

ultrasound, >20,000 Hz

70. ANSWER EITHER (1) What structure on the retina corresponds with the point of fixation? OR (2) What structure on the retina corresponds with the blind spot?

fovea, exit of optic nerve

71. BME graduate student Yasaman Chehreghanianzabi showed a slide of a blue laser beam being focused through a microscope objective onto a sample. What does this laser beam achieve?

it induces fluorescence which is analyzed

72. What does output from the occulomotor nerve (cranial nerve III) do to the pupil?

constricts it

73. The genes for the green (middle wavelength) and the yellow (long wavelength) opsins are located on what chromosome?

the X

74. ANSWER EITHER What does the vertebrate rod have, in its phototransduction cascade, in place of Drosophila's (1) phospholipase C? OR (2) TRP?

phosphodiesterase, the cGMP-gated calcium-sodium channel

75. ANSWER EITHER (1) What decreases the amount of ultraviolet light reaching the human retina? OR (2) What decreases the amount of blue light reaching the foveal cones in the human?

lens, carotenoids lutein and zeaxanthin in the macula lutea


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This page was last updated on November 25, 2014