Key

 

BIOL 260 Human Physiology, Fall 2010, Prof. Stark

Third Hourly Exam, December 6, Short Answer

 

1. The kidney and the liver are two of the three organs used to make 1,25-Dihydrovitamin D3. What is the third organ?

 

skin

 

2. A gland in the neck puts out a hormone that inhibits the dissolution of CaPO4 from bone. Name EITHER (1) the gland or (2) the hormone.

 

Thyroid, calcitonin

 

3. What female hormone is a precursor of testosterone?

 

progesterone

 

4. What are the gonadotropins for spermatogenesis and testosterone secretion?

 

FSH and LH (ICSH)

 

5. Triiodothyroxine binds to a receptor that binds to the half site of a response element. What binds to the receptor that occupies the other half of the response element?

 

Retinoic acid

 

6. Androgens come from the testes and (where else?).

 

adrenal cortex

 

7.  5a-reductase is required for normal function because it makes (what?) out of (what?) [answer both].

 

DHT from testosterone

 

8. Why is an enzyme (as well as acid) a useful secretion of an osteoclast?

 

Digest the collagen that the calcium phosphate was embedded in

 

9. Why were COX-2 inhibitors initially considered to be an important advancement beyond drugs like ibuprofen in the treatment of arthritis?

 

Since they did not inhibit COX-1, they helped in arthritis treatment without gastric side-effects

 

10. Spermatids become spermatozoa. State one of the things that occurs during this process.

 

Cells become separated, cytoplasm is sloughed off and flagella are added

 

11. How is sperm moved along the length of the ductus (vas) deferens?

 

Peristalsis by smooth muscle

 

12. In addition to sperm from the testes, several glandular secretions contribute to semen. Name one of the glands.

 

Prostate, seminal vesicle and bulbourethral (Cowper╣s) gland

 

13. Simultaneous with menstruation, what happens to the corpus luteum?

 

It regresses (becomes corpus albicans)

 

14. │It is the conventional wisdom that men are more likely to have erections when they are asleep.▓ Explain why this is the case in physiological terms.

 

High parasympathetic output

 

15. 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

 

16. At what stage in the process of meiosis is the egg at the time of ovulation?

 

It is a secondary oocyte and has not completed the second meiotic division

 

17. │Then it implants into the endometrium.▓ EITHER (1) name or (2) describe what it is that implants.

 

Blastocyst, ball of cells with inner cell mass, trophoblast and blastocyst cavity

 

18. What capability did embryonic stem cells possess that other cells lacked?

 

Pluripotent or totipotent, can become any type of cells

 

19. Explain why it is safe to assume that cells from the amniotic fluid do not come from the mother.

 

Amnion is on one side, embryo then fetus, on the other and everything is surrounded by chorion, all derived from zygote

 

20. Under the influence of a gene on the Y chromosome, │indifferent gonads▓ turn into a structure that produces Mullerian Inhibiting Factor (MIF) plus (what?).

 

the testes also produce testosterone

 

21. Name a molecule in the cascade leading to fibrin polymer.

 

Hageman factor, prothrombin, thrombin, fibrinogen

 

22. What is the general term for blood that is deficient in red blood cells, hemoglobin, or iron?

 

anemia

 

23. After a white blood cell phagocytoses a bacterium, what does the white blood cell do to dispose of the ingested bacterium?

 

Combine this endosome with lysosomes

 

24. Mast cells help to mediate the inflammatory triad because they release (what substance?).

 

histamine

 

25. Address ONE of the following differences between ABO blood groups and Rh factor: (1) Whether antibodies are made after first exposure vs. they are already present. (2) Whether the couple might have to worry about a mismatch when having children. Or (3) Whether the antibody crosses the placenta.

 

Already present only for ABO, Worry for Rh only, IgG crosses placenta for Rh, not IgM for ABO

 

26. A na´ve B cell is exposed to an antigen. Describe the constituents of the clone of cells that develops from this cell.

 

Plasma cells make antibody, memory cells preserve the information

 

27. │Class-2 MHC molecules are expressed on macrophages and B cells.▓ By contrast, where are class1 MHC molecules expressed?

 

Lots of cells

 

28. 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

 

29. Say something you learned about EITHER IgA or IgE.

 

IgA is transferred to infant via breast feeding, IgE is involved in allergies

 

30. In the 1800s, a famous French physician studied stroke patients. What conclusions did he make upon examining their brains in autopsy that led to the naming of a brain area after him?

 

Broca found a small area on only one side of the brain that mediated the motor aspect of speech

 

31. 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 sensory system?

 

Dorsal white matter of spinal cord, fine touch

 

32. Cells with sensory information make their synapses in the postcentral gyrus. Where are the cell bodies of these cells?

 

thalamus

 

33. Cells in the precentral gyrus innervate muscles in the face via cranial nerves, while the tracts are localized (where?) to reach the motor neurons for the part of the body below the neck.

 

Anterior and lateral parts of the white matter of the spinal cord

 

34. │Huntington╣s was found to be a triplet repeat disease.▓ What does this mean?

 

One DNA triplet (CAG) coding for glutamine expands to too many copies

 

35. The receptor molecule for gustation is either (what?) or (what?).

 

a channel or a G protein coupled receptor

 

36. The chemoreceptive part of the olfactory cell is in the nasal cavity. Where is the synapse?

 

In the olfactory bulb (first cranial nerve) of the brain

 

37. 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

 

38. 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

 

39. The endolymph fluid in the cochlear duct (scala media which bathes the stereocilia) is unusual (for an extracellular fluid) in that it contains a high concentration of (what?)

 

K+

 

40. Helmholtz envisioned that each different frequency stimulated a specific place along the basilar membrane, and that was the explanation why frequency discrimination was so good in the human. How did Bekesy╣s data or explanation differ from Helmholtz╣s original place theory?

 

The localization was far from pinpoint, so neural processing (lateral inhibition) was invoked to explain why the crude place localization would still be sufficient

 

41. There are four or five synapses in the auditory pathway. Where are the terminals of the cells in the thalamus (that receive synaptic input from │further down,▓ the inferior colliculus)?

 

On the auditory part of the cerebral corgtex

 

42. Why are you blind in your blind spot?

 

No receptor cells can be presen t where the optic nerve exits and the blood supply enters and exits

 

43. What happens to your vision when the ciliary muscle is contracted?

 

When ligaments become flaccid, the lens gets rounder, accommodating for near vision

 

44. │Night blindness,▓ │ring scotoma,▓ and │tunnel vision▓ are symptoms of what disorder?

 

Retinitis pigmentosa

 

45. Which portion of the nervous system connects to the iris to mediate the constriction of the pupil elicited by a light stimulus?

 

Parasympathetic, occulomotor nerve (#3), from ciliary ganglion

 

46. Why is there lutein in your vitamin pill?

 

This is one of the carotenoids in the macular pigments that protect foveal cones from blue light

 

47. Young and Helmholtz proposed a widely accepted theory of trichromatic color vision in humans. Answer either (1) what kind of cell, or (2) what kind of molecule has these three specific peak wavelengths of sensitivity?

 

Cone rhodopsin

 

48. Why is it more accurate to refer to women heterozygous for red or green blindness as │mosaics▓ instead of │carriers?▓

 

since it is on the X, they have some cells with one X and the rest of their cells have the other X

 

49. In Prof. Stark╣s research seminar, the rhodopsin promoter or the heat shock promoter was used to drive expression of rhodopsin labeled with green fluorescent protein into the rhodopsin-containing organelle that mediates vision. On what kind of molecule is a promoter?

 

The promoter is the part of the gene upstream of the coding sequence (thus DNA)

 

50. Prof. Stark showed transmission electron micrographs from his own work and work from other researchers of big vesicles in the visual cell that he believed carried rhodopsin into the rhodopsin containing organelle that mediates vision. What cell structure would have produced these vesicles?

 

Rough endoplasmic reticulum via Golgi apparatus