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BIOL 2600 Human Physiology, Fall 2017, Prof. Stark
Third Hourly Exam, Monday December 11, Short Answer
1. 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
2. Upstream of a gene, there is a place where a steroid protein receptor
combined with a steroid hormone binds. What is this area in the DNA called?
a response element
3. What female hormone is a precursor of testosterone?
4. What treatment has been standard for relief of hot flashes?
estrogen replacement therapy
5. The hormone T4 comes up to a cell's plasmalemma in the company of a carrier
protein. Say something about what else is involved before that hormone might
activate a gene's transcription.
converts to T3, binds receptor protein, that protein binds DNA, in the company
of 9-cis retinoic acid bound to RXR receptor
6. What effect if any would castration have on the seminal vesicle?
it would be smaller
7. Why did COX-2 inhibitors show so much promise, and why were some pulled
from the market?
relieve arthritic inflammation without interfering with gastric mucosa,
increased chance of heart attack
8. Why would hyperplasia of the adrenal masculinize a female?
adrenal cortex makes anabolic steroids like testosterone, too much if there
9. The enzyme 5-alpha-reductase is thought to be involved in androgenic
alopecia. Answer either (1) What is androgenic alopecia? or (2) What product
of 5-alpha reductase might contribute to androgenic alopecia?
baldness in men, dihydrotestosterone
10. After the zygote is first formed, but before implantation, some rudimentary
development occurs. Answer either (1) What is the term used for these cell
divisions? or (2) Where do they take place?
cleavage, uterine (fallopian) tube
11. In your textbook's diagram of the seminiferous tubule, cells called
"spermatogonia" were shown. No analogous "oogonia" were
shown in the diagrams of the ovary. Why not?
there are no oogonia after 3 months of age
12. A low PSA reading is around 1 while a high PSA is 5. What does PSA stand
prostate specific antigen
13. What is the "egg" called officially at the time of ovulation,
and what stage of meiosis or mitosis is it in at that time?
secondary oocyte, before meiosis II is complete
14. What capability did embryonic stem cells possess that other cells lacked?
pluripotent or totipotent, can become any type of cells
15. What would have happened to a person who did not have Mullerian Inhibiting
primordial "plumbing" would become uterus and uterine tubules
16. Considering how much fibrin is around when clotting is needed, how come
fibrin does not make blood clot all the time?
unless cleaved by clotting cascade, fibrinogen is inactive
17. Why did AIDS, in the first few years, create a new "selection pressure"
before AIDS, the "environment" was one where clotting factor was
available through medical technology; after AIDS (before the blood banks
were better secured) this factor from multiple blood donors had a grim chance
of being infected
18. Why are lysosomes an important part of phagocytic leukocytes?
they merge with endosomes to digest them
19. Why is AB the universal recipient?
no A or B antibodies
20. Some bacteria come in through a small skin injury. How do phagocytitc
cells get from an intact capillary to the site of the injury?
chemotaxis, slither between endothlial cells
21. Explain what agglutination is using transfusion of type A blood into
a type B recipient as your example.
antibodies would cause red blood cells to clump together
22. Class II MHC (major histocompatability complex) is expressed only on
macrophages and B lymphocytes. What about class I?
all cells, involved in attack on infected cells
23. Which specific type of white blood cell is depleted in AIDS (acquired
24. What kind of protein is the antigen receptor on the surface of a B lymphocyte?
25. Axons for one sensory system are in the dorsal columns. Answer either
(1) Where are these dorsal columns? Or (2) What is being perceived by this
dorsal white matter of spinal cord, fine touch
26. In terms of localization of function of the cerebral cortex, what is
the function of the postcentral gyrus?
27. Cells with sensory information make their synapses in the postcentral
gyrus. Where are the cell bodies of these cells?
28. Where is the decussation (cross over) of the lemniscal system for localized
29. Where does the globus pallidus feed to?
to thalamus to motor cortex
30. 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 ahd ask where
(s)he feels a tingle
31. What would happen to the coding sequence of the mutant allele for Huntington's
chorea from one generation to the next?
there would be more CAG's coding for more glutamines
32. In the vestibular system there are 3 fluid-filled (what) plus 2 organs
with otoliths, the (what?) and the (what?). [Answer one of the above.]
semicircular canals, utricle & saccule
33. About how many different G protein coupled receptors are involved in
34. What is PTC (phenylthiocarbamide) and what did it reveal about sensory
a substance that tastes bitter and helped in the isolation of the G protein-coupled
35. "Sound intensity is measured in log units." Be more specific
dB is 20 log ratio of pressures
36. Tip links between stereocilia contribute to channels responsible for
what kind of stimulation?
mechanosensation, or hearing, or balance, possibly K+
37. What is compared that would allow you to tell which side of your head
a sound is coming from?
inputs from the two ears
38. Helmholtz proposed that different frequencies stimulated different places
along the basilar membrane. In what way(s) was his place theory confirmed
true, but localization is crude, lateral inhibition corrects for this
39. How is it that K+ moves in, rather than out, through channels in auditory
an unusual extracellular fluid (endolymph) is high in K+
40. Some animals can hear ultrasound. How does ultrasound differ from the
sounds humans can hear?
it is a higher frequency, higher than 20,000 Hz
41. "A laser is used to destroy patches of the retina." Answer
either (1) Who might actually benefit from this procedure? or (2) Why would
the ophthalmologist avoid blasting the fovea with the laser?
a diabetic, fovea is too essential for high acuity color vision at the point
42. Why are you blind in your blind spot?
no receptor cells can be present where the optic nerve exits and the blood
supply enters and exits
43. Which side of the retina projects to the ipsilateral thalamus (lateral
geniculate body) at the optic chiasm?
44. What kind of lens corrects for myopia (near-sightedness)?
45. Other than serving as the "black paint" that keeps light from
reflecting around the eye, state another function of the retinal pigment
phagocytose shed rod disks, chemical reactions to replenish 11-cis-retinal
46. Why would we use the term "tunnel vision" for the blindness
in retinitis pigmentosa?
rods in a circle around the point of fixation degenerate
47. Why are you unable to see ultraviolet light (while I can)?
the lens blocks UV, I had a lens removed
48. In phototransduction, the heterotrimeric G protein's alpha subunit activates
an enzyme. For EITHER Drosophila OR humans, what is that enzyme?
phospholipase C or cGMP" PDE
49. "Vitamin A is the chromophore of rhodopsin." We get this vitamin
A from what dietary precursor?
carotenoids like beta carotene
50. Say something about the garbage that accumulates in cells of the aging
called lipofuscin, autofluoresces yellow, in retinal pigment epithelium
cells, from shed photoreceptor tips
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last updated 12/5/2017