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·
Sign your
form in the upper right.
Multiple
choice: As always, choose the best
answer for each multiple-choice question.
Answer on your scantron form.
Each question is worth 3 points.
1. Which of the following is not a complex carbohydrate?
a.
A
disaccharide
b. A polysaccharide
c. A starch molecule
d. A glycogen molecule
e. All of the above are complex carbohydrates.
2. From a physiological standpoint, chyme in the lumen of the gut is located
a. intracellularly.
b. interstitially.
c. in the blood.
d. within the internal environment of the body.
e.
outside the
body.
3. The main trigger for the release of cholecystokinin is
a. chewing and swallowing of food.
b. food in the stomach.
c. acidic chyme in the small intestine.
d.
fats and
proteins in the small intestine.
e. fecal matter in the large intestine.
4. The activation of the enzymes chymotrypsin and carboxypeptidase depends directly on
a. the acidity of the stomach.
b. the relative alkalinity of the small intestine.
c. pepsin.
d. enterokinase.
e.
trypsin.
5. Fats (triglycerides) that have been digested and absorbed end up in the bloodstream in the form of
a. fatty acids.
b.
fats
(triglycerides).
c. micelles.
d. cholesterol.
e. Absorbed fats never enter the bloodstream.
6. Increased amounts of insulin are released
a. from the alpha cells of the pancreas in response to an increase in blood glucose.
b. from the alpha cells of the pancreas in response to a decrease in blood glucose.
c.
from the beta
cells of the pancreas in response to an increase in blood glucose.
d. from the beta cells of the pancreas in response to a decrease in blood glucose.
e. Insulin levels in the body are unchanging.
7. The fact that many obese people have high levels of circulating leptin suggests that
a. they are releasing too much leptin for their weight.
b. their fat cells are acting abnormally.
c.
they are
failing to respond appropriately to leptin.
d. they are eating too few calories.
e. they are eating too little protein.
8. The kidneys are directly responsible for regulating the composition of
a. the intracellular fluid.
b.
the
extracellular fluid.
c. the cerebrospinal fluid.
d. a and b.
e. All of the above.
9. If you injected an inert substance into your bloodstream, it should eventually be removed by your kidneys provided that
a. it is structurally similar to a substance normally removed by the kidneys.
b.
it is small
enough to filter out of the glomerulus and into Bowman’s capsule.
c. there are carrier proteins that can secrete it into the proximal tubule.
d. there are carrier proteins that can secrete it into the distal tubule.
e. it precipitates out of the blood.
10. If substance U is filtered at the glomerulus at the rate of 10 mg/min and enters the bladder at the rate of 5 mg/min we can say that U is
a.
reabsorbed.
b. secreted.
c. neither secreted no reabsorbed.
d. actively transported.
e. not present in the blood.
11. If the primary urine (= glomerular filtrate) contained no sodium, the proximal tubule would probably have trouble reabsorbing normal amounts of
a. glucose.
b. water.
c. urea.
d. Two of the above.
e.
All of the
above.
12. The loop of Henle shows
a. permeability to water in the descending limb and active transport of sodium in the thin ascending limb.
b.
permeability
to water in the descending limb and active transport of sodium in the thick
ascending limb.
c. permeability to sodium in the descending limb and active transport of sodium in the thin ascending limb.
d. permeability to sodium in the descending limb and active transport of sodium in the thick ascending limb.
e. None of the above.
13. By the time the urine reaches the end of the loop of Henle, the flow per minute (or volume per minute) has decreased from about 120 ml at Bowman’s capsule to about
a. 80 ml
b. 40 ml
c.
20 ml
d. 5 ml
e. 1 ml
14. Renin is
a. a hormone released by the kidneys.
b.
an enzyme
released by the kidneys.
c. a hormone released by the liver.
d. an enzyme released by the liver.
e. a hormone released by the adrenal cortex.
15. Blood flow through body tissues is driven most directly by
a. heart rate.
b. stroke volume.
c.
arterial
blood pressure.
d. venous blood pressure.
e. blood volume.
16. A respiratory acidosis results from
a. low levels of CO2 in the blood.
b.
high levels
of CO2 in the blood.
c. low levels of lactate in the blood.
d. high levels of lactate in the blood.
e. Two of the above.
17. In human females, the pattern of secondary hair growth is due to increasing levels of
a. GnRH.
b. FSH.
c.
estrogen.
d. progesterone.
e. androgens.
18. In mature men, the primary direct effect of luteinizing hormone is to
a. promote spermatogenesis.
b. stimulate Sertoli cells to release paracrine agents.
c. stimulate Sertoli cells to release inhibin.
d.
stimulate
Leydig cells to release testosterone.
e. Two of the above.
19. In mammals, diploid cells that give rise to spermatozoa are known as
a. Leydig cells.
b. Sertoli cells.
c. seminiferous cells.
d. luminal cells.
e.
spermatogonia.
20. A new drug, targeting the Viagra market, is released that claims to stimulate the parasympathetic nervous system while inhibiting the sympathetic nervous system. Which of the following describes the most likely effect of this drug on a man?
a. He would find it harder to achieve erection but the ejaculatory response might be stronger.
b.
He would find
it easier to achieve erection but the ejaculatory response might be compromised.
c. He would find it harder to achieve erection and the ejaculatory response might be compromised.
d. He would find it easier to achieve erection and the ejaculatory response might be stronger.
e. His hair would grow back.
21. The total number of eggs released from the ovaries of a typical woman is on the order of
a. tens.
b.
hundreds.
c. thousands.
d. tens of thousands.
e. hundreds of thousands.
22. During the middle of the luteal phase, the corpus luteum produces relatively large amounts of
a. progesterone.
b. estrogen.
c. luteinizing hormone.
d.
Two of the
above. (a and b)
e. All of the above.
23. In humans, the delay between fertilization and implantation is about
a. one hour.
b. six hours.
c. 24 hours.
d. three days.
e.
six days.
24. An antibody that bound to chorionic gonadotropin, thus rendering it inactive, would likely
a. prevent an embryo from implanting but have no effect on an established embryo or fetus.
b.
cause
termination of a pregnancy during the first trimester but have no effect after
that.
c. have no effect during the first trimester but cause termination of a pregnancy after that.
d. cause termination of a pregnancy at any stage.
e. have no effect on a pregnancy at any stage.
Where did my last multiple
choice question go? Oh well – three free
points for everyone!
Short answer: Write a concise answer to each of the following questions. Diagrams may be used but will typically require supporting text. Your answers should fit in the spaces provided. Each question is worth 4 points.
25. Discuss the
release and activity of pepsin in the stomach.
What promotes its release, where does it come from, how does it become
active and what does it do?
The release of pepsinogen from the chief
cells of the stomach is promoted the hormone gastrin (as well as the
parasympathetic nervous system). Once in
the stomach, the acidic conditions convert pepsinogen into the active form
pepsin, which acts to break proteins into peptides.
26. What are
the two types of tissue currently believed to respond to glucagon, and what are
the effects of increased glucagon levels on these tissues?
Glucagon is thought to affect mainly the
liver and adipose tissues (fat cells).
In response to increased levels, the liver increases glycogenolysis (the
breakdown of glycogen to produce glucose) and gluconeogenesis (the production
of glucose from amino acids), and then releases this glucose into the
bloodstream. Fat cells respond to
glucagon by increasing lipolysis (the breakdown of fats into fatty acids) and
the release of fatty acids into the blood.
27. What are the
results of osmoreceptors in the hypothalamus sensing increased plasma
osmolarity? You should discuss the
effects of any hormones, but do not need to discuss these effects at the
cellular level.
The major effect of an increase in
osmolarity on the hypothalamus is to promote the increased release of
anti-diuretic hormone (via the posterior pituitary). Increased levels of ADH cause the tubule wall
of the collecting duct to become more permeable to water, causing more water to
be absorbed from the fluid traveling down the duct. As a result, a smaller volume of more
concentrated urine is formed, thus helping to minimize further increases in ECF
osmolarity.
28. Heat
exhaustion occurs in part due to dehydration and greatly increased blood flow
to the skin in an effort to stay cool.
Given what you know about the determinants of blood pressure, what might
be the consequences of these factors on the circulatory system?
Dehydration means reduced fluid volume,
which means reduced blood volume, which will tend to reduce arterial blood
pressure by reducing venous return to the heart. Increased bloodflow to the skin would require
vasodilation in the skin, which means reduced total peripheral resistance,
which will likewise tend to reduce blood pressure. If you discussed responses, the major acute
ones would be an increase in heart rate (to increase cardiac output) and
vasoconstriction in other organs (to help bring TPR back up).
29. Describe
the normal developmental pathway for the gonads and internal reproductive
organs in a human female from fetal weeks 6 to 12. Be sure to indicate the cause of each event.
A female fetus lacks a Y chromosome, and
hence an srY gene. When no srY gene
product (testis-determining factor) is produced, the protogonads will develop
into ovaries instead of testes. Lacking
testes, the fetus does not produce testosterone or Müllerian inhibiting
substance. Without testosterone, the
Wolffian ducts degenerate (rather than developing into the male reproductive
tract). And since there is no MIS, the Müllerian
ducts do develop, into the female reproductive tract.
30. Describe
the hormonal pathways (promotion of hormone release, negative feedback loops,
etc.) of the female reproductive system as they occur during the first week of
a woman’s menstrual cycle.
This is the early-to-mid follicular
phase. The hypothalamus releases
gonadotropin releasing hormone, which promotes release of follicle stimulating
hormone and luteinizing hormone from the anterior pituitary. The LH promotes the release of androgens from
the theca cells of the follicle(s), while the FSH promotes the activity of the
granulose cells of the follicles. This
activity includes the conversion of the androgens into estrogen and the release
of inhibin. Inhibin then has negative
feedback effects on the release of FSH, while the estrogen (at this stage)
inhibits the release of GnRH and LH.
Estrogen also has other effects in the follicle and elsewhere.