| Biology 449 - Animal Physiology | Fall 2005 |
Fill in your scantron form as follows. This is worth 1˝ points:
· Write and bubble in your name in the upper left (last name first).
· Follow any additional instructions provided in class.
·
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 2˝ points.
1. Into which of the following categories does glycogen fall?
a. Disaccharides
b. Monosaccharides
c. Proteins
d. Starches
e. Triglycerides
2. Food passing from the lumen of the gut, through the epithelial cells and into the bloodstream is undergoing
a. absorption.
b. digestion.
c. mastication.
d. motility.
e. peristalsis.
3. Which of the following types of food will be at least partially digested before they reach the small intestine?
a. Fats
b. Proteins
c. Starches
d. Two of the above (b and c)
e. All
of the above
4. During the formation of large amounts of hydrochloric acid for secretion into the stomach, extracellular fluid (including blood) will show an increase in the concentration of
a. Cl-.
b. H+.
c. HCO3-.
d. Na+.
e. carbonic
anhydrase.
5. The presence of villi and microvilli in the small intestine is important mainly because
a. they help increase the total surface area.
b. they help to physically separate digestible and non-digestible material.
c. they help to trap food particles.
d. they serve to mix the hime.
e. they secrete proteases.
6. After a day of fasting, levels of gastrin in the blood should be low primarily because
a. the stomach is empty.
b. the small intestine does not contain acidic hime.
c. the small intestine does not contain fats and proteins.
d. water is no longer being absorbed in large amounts.
e. blood
flow to the gastrointestinal tract is reduced.
7. If bile salts were not present in the small intestine, the primary effect would be that
a. there would be no trigger for the release of lipases.
b. lipases would not be activated.
c. lipases could not effectively attack fats.
d. fatty acids could not be absorbed by the epithelium.
e. chylomicrons could not be formed.
8. Which of the following relaxes reflexively as the result of a mass movement in the gastrointestinal tract?
a. The external anal sphincter.
b. The internal anal sphincter.
c. The pancreatic sphincter.
d. The pyloric sphincter.
e. The sphincter of Oddi.
9. The amount of energy stored as carbohydrate by most humans would provide enough fuel to run the body (at the minimal metabolic rate) for about
a. one hour.
b. four hours.
c. one day.
d. one week.
e. one
month.
10. Neuropeptide Y is a chemical messenger that
a. increases
metabolic rate.
b. promotes the metabolism of fat rather than glucose.
c. provides information on the fat content of the body.
d. stimulates appetite.
e. inhibits the response to leptin.
11. The hollow space at the core of the kidney that the collecting ducts drain into is known as the
a. renal cortex.
b. renal medulla.
c. renal pelvis.
d. ureter.
e. urinary
bladder.
12. If the concentration of Cl- in the plasma is 100 mM, then the concentration of Cl- in the fluid entering Bowman’s capsule in a nephron should be
a. 0 mM.
b. more than 0 but significantly less than 100 mM.
c. about 100 mM.
d. significantly more than 100 mM.
e. It is impossible to estimate what the concentration of Cl- would be.
13. One example of a substance that is normally completely reabsorbed from the urine is
a. glucose.
b. sodium.
c. urea.
d. water.
e. More than one of the above.
14. The reabsorption of water in the collecting duct involves movement of the water
a. directly through the lipid bilayer of the epithelial cells.
b. through aquaporins inserted into the
epithelial cell membrane.
c. through the tight junctions of the epithelial cells.
d. through small gaps between the epithelial cells.
e. Water does not get reabsorbed from the collecting duct.
15. If the osmolarity of the blood drops significantly below normal, which of the following patterns would be expected?
a. Low levels of ADH release and the formation of a concentrated urine.
b. Low levels of ADH release and the formation
of a dilute urine.
c. Intermediate
levels of ADH release and the formation of a urine of intermediate
concentration.
d. High levels of ADH release and the formation of a concentrated urine.
e. High levels of ADH release and the formation of a dilute urine.
16. Over the normal range of blood pressure changes experienced by a healthy person
a. glomerular filtration rate is directly proportional to blood pressure because the higher pressure drives more blood flows through the glomeruli.
b. glomerular filtration rate is directly proportional to blood pressure because the afferent arterioles dilate more as blood pressure increases.
c. glomerular filtration rate is approximately constant because filtration is not driven by blood pressure.
d. glomerular filtration rate is approximately
constant because the afferent arterioles constrict more as blood pressure
increases.
e. glomerular filtration rate is inversely proportional to blood pressure because the afferent arterioles constrict exponentially as blood pressure increases.
17. A loss of blood volume ultimately leads to a drop in mean arterial pressure. Which of the following is an incorrect component in the chain of events that explains this relationship?
a. A drop in blood volume leads to…
b. a drop in central venous pressure leads, which leads to…
c. a drop in the venous return of blood to the heart, which leads to…
d. a drop in ventricular volume at the start of systole, which leads to…
e. an increase in stroke volume, which leads
to…
a drop in mean arterial pressure.
18. Which of the following would not be expected to increase following a blood loss?
a. Anti-diuretic hormone levels
b. Renin levels.
c. Aldosterone levels.
d. Atrial natriuretic factor levels.
e. Thirst.
19. If you examined the urine of a person experiencing a metabolic alkalosis, you would expect to see
a. lower then normal levels of bicarbonate ions.
b. normal levels of bicarbonate ions.
c. higher than normal level of bicarbonate
ions.
d. Urine never contains bicarbonate ions.
e. It is not possible to experience a metabolic alkalosis.
20. If a person shows higher than normal levels of carbon dioxide in her alveoli and has blood with a pH of 7.1, she is most likely suffering from
a. metabolic acidosis.
b. metabolic alkalosis.
c. respiratory acidosis.
d. respiratory alkalosis.
e. avian flu.
21. In human males, erection of the penis involves
a. vasodilation of arterioles entering the penis.
b. physical constriction of the veins draining the penis.
c. contraction of the erector magister muscle.
d. Two of the above. (a and b)
e. All of the above.
22. The process of meiosis is fully completed in mammalian oocytes
a. prior to the birth of the female.
b. during puberty.
c. during follicular development.
d. at ovulation.
e. at fertilization.
23. In human females, estrogen levels rise during the mid-follicular phase (around day 7 of the menstrual cycle) because
a. levels of inhibin are decreasing.
b. chorionic
gonadotropin levels are increasing.
c. follicle-stimulating hormone levels are spiking.
d. the cycle has reached the positive feedback stage.
e. the granulosa cells are proliferating.
24. During the follicular phase, the androgens that are converted into estrogen are produced by the
a. anterior pituitary.
b. corpus luteum.
c. granulosa cells.
d. oocytes.
e. theca cells.
25. In human females, cervical mucus is normally thinnest around which day of the menstrual cycle?
a. Day 1
b. Day 7
c. Day 14
d. Day 21
e. Cervical
mucus thins only during pregnancy.
Short answer: Write a concise answer to each of the
following questions. Your answers should
fit in the spaces provided and should address only the question asked. Diagrams must be accompanied by written
explanations. Each question is worth
6 points.
26. While
snacking on leftover food from an abandoned buffet in the Hixson-Lied atrium,
you ingest some bacteria that release a chemical that blocks secretin
receptors. In other words, secretin no
longer has any effect on target tissues.
What might some of the effects of this unfortunate occurrence be on the
contents and activity of the upper GI tract, and on secretin levels in the
blood?
Secretin normally helps to reduce acid
levels in the small intestine by inhibiting acid release by the stomach,
slowing the rate of stomach emptying, and promoting bicarbonate release by the
pancreas and liver. With the secretin
receptors blocked, these responses to secretin would not be seen, and chyme in
the stomach would move to the SI much more quickly than normal and remain more
acidic than normal. As the SI becomes
more and more acidic, it will release more and more secretin as part of the
(non-functioning) feedback system, so blood levels of the hormone will
increase.
27. Consider
a glucose molecule entering the bloodstream in the capillaries of the small
intestines. What possible fates might
this molecule have? It may be helpful to
think about the various organs and tissues we discussed in the context of the
absorptive and post-absorptive state.
If this occurs during the absorptive
phase (as would occur after a reasonably sized meal), the glucose molecule
might end up being “burned” for immediate energy needs (via oxidative
phosphorylation) by any of the cells in the body, it might be converted to
glycogen and stored by the liver or muscles, or it might be converted to (part
of) a fat by fat cells or the liver for storage. If the molecule was absorbed during the
post-absorptive phase* or released from glycogen storage in the liver, it would
likely be burned by neural tissue, since other tissues are using fatty acids
for fuel. Muscles might also use glucose
released from storage in their internal stores.
* If only a small amount of calories are taken in, blood glucose levels may not
rise enough to shift the body into the absorptive state.
28. In the following diagram of the nephron, please indicate clearly for each major region where and in what direction:
a. water is moving in or out of the nephron.
b. Na+ is diffusing.
c. Na+ is being actively transported.
Also indicate the
approximate concentration of the fluid inside and outside the nephron in each
region. Assume that the person is
dehydrated. You do not need to indicate
what is occurring in the distal tubule.
The diagram should show active transport
of sodium and movement of water out of the proximal tubule, movement of water
out of the descending loop of Henle, passive movement of sodium out of the thin
ascending loop, and water moving out of the collecting duct. Fluid levels inside the nephron should be 300
mOsm in the proximal, about 1200 at the bottom of the loop, between 100 and 300
at the top of the loop, and a high value (due to the dehydrated date) at the
end of the collecting duct – in the 800 to 1200 range. External values should range from 300 mOsm at
the top to about 1400 at the bottom of the nephron.
29. Using
a flow chart or a list of events, describe the hormonal pathway involved in the
release of aldosterone. Be sure to
indicate what triggers the release of each compound in the pathway (when
appropriate), and what each compound’s effects are. Also indicate which substances are hormones
and which are enzymes.
The enzyme renin is released in response
to a number of factors, including low blood pressure, low GFR, and low sodium
levels in the urine. Once released into
the bloodstream, renin activates the prohormone angiotensinogen, which is
constantly released by the liver, converting it to the hormone angiotensin
I. Angiotensin converting enzyme
(present at high concentrations in the alveoli of the lungs) converts
angiotensin I to angiotensin II (still a hormone). Angiotensin II causes vasoconstriction, which
helps increase blood pressure, and promotes the release of the hormone
aldosterone from the adrenal cortex.
Aldosterone promotes increased reabsorption of sodium from the nephron,
which increases blood sodium levels and thus helps increase blood volume again.
30. Describe
process by which semen is formed during emission, including in your discussion
all the relevant anatomical elements and the components that make up the semen.
Semen is formed in the ejaculatory duct
from the following components: Mature
sperm are transported from the epididymis through the vas deferens via
peristalsis to the duct. The seminal
vesicles release fluids that include mucus, fructose, prostaglandins and
proteins (including those involved in coagulation) into the duct. The prostate gland releases additional fluid
that contains citrate and anticoagulants.
Together these substances form the semen. The bulbourethral gland may contribute some
additional components, but its secretions appear to be more important in the
pre-ejaculatory release of lubricants and alkaline substances.
31. List the
important effects of the high levels of estrogen and progesterone during
pregnancy.
Important effects of estrogen include
promotion of :
Continued proliferation of the endometrial layer of the uterus, as well as
development of the myometrium
Relaxation of the pelvic ligaments
Duct development and fat storage in the breasts
Insertion of oxytoxin receptors in the uterus late in the pregnancy
Prolactin release
Estrogen also helps inhibit lactation during pregnancy
Effects of progesterone include promotion of:
Continued secretion of glands in the endometrium
Development of mammary glands
Progesterone also helps inhibit lactation and premature uterine contractions.