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
6. In a signal transduction cascade involving phospholapase C, what is released
from the smooth endoplasmic reticulum in response to stimulation by a hormone?
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
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
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?
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
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
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
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
there is less actin - myosin overlap
21. What does the binding of calcium ions to troponin do to facilitate the
pulls tropomyosin off of actin's binding sites for myosin
22. During heavy exercise, what is the predominant source of energy in muscle?
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
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?
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
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?
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
34. There is a greatly decreased surface area for gas exchange in the alveoli
in what lung disease?
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?
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
hypothalamus (supraoptic and paraventricular nucleus)
44. In addition to oxytocin, what pituitary hormone affects the mammary
45. A surge in a hormone (from where?) triggers ovulation.
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?).
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.
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
it involved the creation and destruction of embryos
55. Why are the techniques of amniocentesis and chorionic villus biopsy
to screen for birth defects
56. How is extravasation related to chemotaxis in a phagocytic white blood
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
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
class-1 MHC molecule on the infected cell and CD8 coreceptor on the killer
61. Bradykinin is used in what sensory system?
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?
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
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
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
73. The genes for the green (middle wavelength) and the yellow (long wavelength)
opsins are located on what chromosome?
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