| Biology 449 - Animal Physiology | Fall 2005 |
160 points total
Fill in your scantron form as follows:
· 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. If you are uncertain about the nature of the question, please ask! Answer on your scantron form. Each question is worth 2½ points.
1. In a healthy vertebrate, a high concentration of potassium relative to sodium would be associated with
a. intracellular fluid.
b. interstitial fluid.
c. blood plasma.
d. Two of the above.
e. All of the above.
2. In the regulation of body temperature, a drop in basal metabolic rate would be classified as
a. decreased input.
b. increased input.
c. decreased output.
d. increased output.
e. None of the above classifications would apply.
3. One of the disadvantages to physiological regulation is that
a. it tends to limit an animal to a narrow range of environments.
b. it is only effective at certain times.
c. body cells experience every change in the external environment.
d. it is energetically expensive.
e. it maintains a relatively constant internal environment.
4. “Active transport” of material across a cell membrane differs from other forms of cross-membrane transport in that
a. it involves channel proteins.
b. it involves carrier proteins.
c. it involves phagocytosis and exocytosis.
d. it occurs down a concentration gradient.
e. it involves energy input by ATP.
5. Calculation of a membrane potential using the Nernst equation requires knowing the values for all of the following except
a. temperature.
b. the ion valance.
c. the concentration of the ion on each side of the membrane.
d. the permeability of the membrane to the ion.
e. All of the above are required variables in the Nernst equation.
6. The opening of voltage-gated K+ channels during an action potential is triggered directly by
a. membrane depolarization.
b. membrane repolarization.
c. membrane hyperpolarization.
d. opening of voltage-gated sodium channel activation gates.
e. closing of voltage-gated sodium channel inactivation gates.
7. Ionotropic receptors in a neural synapse could also be described as
a. voltage-gated ion channels.
b. ligand-gated ion channels.
c. voltage-activated G protein systems.
d. ligand-activated G protein systems.
e. pores that electrically connect two neurons.
8. In the diagram at right, neuron B synapses with neuron C (C is the postsynaptic neuron). Other neurons (not shown) also synapse with C. In addition, neuron A synapses with the axon terminal of neuron B. If A has inhibitory effects and B has inhibitory effects, how would the membrane potential in C change if both A and B increased their rate of action potentials?
a. Neuron C would become more depolarized (increased membrane potential).
b. Neuron C would become less depolarized (decreased membrane potential).
c. The membrane potential in C would be unchanged.
d. It is impossible to know for certain how the membrane potential in C would change.
e. Some maniac has cut the arms off all these stick men!
9. The sensory cells called hair cells are associated with
a. baroreception.
b. chemoreception.
c. mechanoreception.
d. photoreception.
e. thermoreception.
10. Umami taste receptors appear to be most strongly stimulated by
a. simple carbohydrates (sugars).
b. complex carbohydrates (starches).
c. amino acids.
d. fats.
e. flavenoids.
11. If a person moves from dim to bright light, the eye compensates for the change in light intensity through
a. constriction of the pupil.
b. decreasing sensitivity in the photoreceptors (adaptation).
c. the use of a nictitating membrane.
d. Two of the above.
e. All of the above.
12. Which type of hormone receptor directly controls gene expression?
a. Channel protein-linked receptors.
b. Enzyme-linked receptors.
c. G-protein-linked receptors.
d. Intracellular receptors.
e. Nucleonic receptors.
13. An example of a hormone released from the posterior pituitary is
a. cortisol
b. gonadotropin releasing hormone.
c. growth hormone releasing hormone.
d. oxytocin.
e. somatostatin.
14. Which of the following types of molecules could be missing without preventing cross-bridge cycling from occurring in a sarcomere?
a. actin.
b. adenosine triphosphate.
c. myosin.
d. tropomyosin.
e. All these molecules are necessary for cross-bridge cycling.
15. While competing on Survivor, you participate in a contest that requires you to push a large stone. You try as hard as you can, but are unable to get the stone to move at all. How would you classify the contractions shown by most of your muscles as you push?
a. Isometric twitch contractions.
b. Isometric tetanic contractions.
c. Isotonic twitch contractions.
d. Isotonic tentanic contractions.
e. I didn’t want a million dollars anyway.
16. Which of the following statements about motor units in mammals is true?
a. They normally include just one or two muscle fibers.
b. They normally include multiple fiber types.
c. They are normally all activated at once.
d. They normally contain more fibers if the fibers are fast glycolytic and less if the fibers are slow oxidative.
e. The same fiber may be innervated by multiple neurons.
17. Which types of myocardial cells show myogenic production of action potentials?
a. Cells in the sinoatrial node.
b. Cells in the atrioventricular node.
c. a and b.
d. All myocardial cells are myogenic.
e. No myocardial cells spontaneously depolarize.
18. When the atria of a healthy mammalian heart contract,
a. blood flows into the ventricles but not the vena cava or pulmonary vein because one-way valves prevent backflow.
b. blood flows into the ventricles but not the vena cava or pulmonary vein because pressure is lower in the ventricles than the veins.
c. blood flows into the ventricles but not the vena cava or pulmonary vein because the veins contract at the same time as the atria.
d. blood flows into the vena cava and pulmonary vein but not the ventricles.
e. blood flows into both the ventricles and the vena cava and pulmonary vein.
19. According to Poiseuille’s Law, which of the following would cause a decrease in the flow of fluid through a tube?
a. increasing the radius of the tube.
b. increasing the length of the tube.
c. increasing the pressure differential along the tube.
d. decreasing the viscosity of the fluid.
e. Two of the above.
20. The fluid known as lymph doesn’t accumulate in healthy people because
a. it is transported to the kidneys and added to the primary urine.
b. it is transported to the venous side of the circulatory system and returned to the blood.
c. it is secreted through the skin as sweat.
d. it is transported to the lumen of the small intestine and reabsorbed.
e. it is used to make mucus.
21. The elasticity of the lungs is due to
a. the presence of elastin fibers.
b. the surface tension of the fluid lining the alveoli.
c. the compressive force of the intrapleural membrane.
d. Two of the above.
e. All of the above.
22. A tracheotomy is a medical procedure in which a hole is cut through the trachea just below the larynx, creating a direct opening to the air in order to bypass a blockage in the pharynx or larynx. In comparison to a normal person, a person with a tracheotomy would likely show which of the following changes in ventilatory pattern? (Assume both individuals are at rest and taking the same number of breaths per minute.)
a. A lower tidal volume.
b. A higher tidal volume.
c. A lower alveolar ventilation rate.
d. A higher alveolar ventilation rate.
e. Both individuals would show the same ventilatory patterns.
23. If a normal person breathed a high oxygen gas mixture until the PO2 in his alveoli increased to 200 torr, the total oxygen content of his blood (ml O2/liter) would
a. roughly double.
b. roughly triple.
c. roughly quadruple.
d. not change very much.
e. paradoxically decrease.
24. Among the reasons that more oxygen is delivered to active tissues than to resting tissues from each ml of blood is
a. the lower partial pressure of oxygen in active tissues.
b. the Bohr effect on the oxygen saturation curve.
c. the temperature effect on the oxygen saturation curve.
d. Two of the above.
e. All of the above.
25. Which of the following is not normally secreted by the stomach?
a. Hydrochloric acid
b. Mucus
c. Pepsin(ogen)
d. Bile
e. All of the above are secreted by the stomach
26. The secretion of proteases into the small intestine is promoted primarily by the hormone
a. cholecystokinin.
b. gastrin.
c. glucagon.
d. insulin.
e. secretin.
27. The absorption of glucose from the small intestine is generally via
a. simple diffusion.
b. permeation.
c. symport transport with Na+.
d. antiport transport with K+.
e. glucose ATPase.
28. Substances that can be broken down into or converted into glucose during the post-absorptive phase include
a. glycogen.
b. amino acids.
c. fatty acids.
d. Two of the above.
e. All of the above.
29. Of the amount of water filtered at Bowman’s capsule, what percentage is ultimately excreted by a person with a normal hydration state?
a. 0.1%
b. 1%
c. 10%
d. 50%
e. 100%
30. Substances that leave the urine in the descending loop of Henle include
a. glucose.
b. sodium.
c. water.
d. Two of the above.
e. All of the above.
31. Recall that chloride ions are reabsorbed in the proximal tubule along with sodium. During reabsorption, the chloride ions pass through
a. the same membrane channels as sodium ions.
b. separate membrane channels.
c. chloride transporterers.
d. sodium/chloride cotransporters.
e. tight junctions.
32. Factors that directly promote the release of anti-diuretic hormone include
a. low blood pressure.
b. low glomerular filtration rate.
c. high blood osmolarity.
d. Two of the above.
e. All of the above.
33. One response to a metabolic acidosis should be
a. decreased ventilation.
b. increased ventilation.
c. decreased thirst.
d. increased thirst.
e. diarrhea.
34. The diploid cells that give rise to sperm in mammals are known as
a. Leydig cells.
b. seminiferous cells.
c. Sertoli cells.
d. spermatogonia.
e. spermatozoa.
35. The primary hormone involved in the production of milk is
a. chorionic gonadotropin.
b. estrogen.
c. oxytocin.
d. progesterone.
e. prolactin.
36. Among the defenses that keep bacteria and other pathogens from entering people through external body surfaces are
a. a relatively impermeable skin.
b. glands whose products include antimicrobial agents.
c. an existing fauna of non-pathogenic microbes living on body surfaces.
d. Two of the above.
e. All of the above.
37. Natural killer (NK) T cells differ from cytotoxic T cells in that
a. they are not keyed to a particular antigen.
b. they are phagocytes.
c. they release antibodies.
d. they cannot kill the body’s own cells.
e. they can kill the body’s own cells.
38. In most cases, an antigen will be recognized by
a. any B cell that encounters it.
b. many B cells.
c. no more than a few B cells.
d. B cells do not respond to antigens.
e. Don’t choose e!
39. The function served by the major histocompatibility complexes is
a. to identify the cell as “self”.
b. to present antigens from within the cell.
c. to match antigens being presented by other cells.
d. a and b.
e. a and c.
40. One drawback to the specific or acquired immune system is that
a. it is only effective against bacteria.
b. it cannot directly kill or incapacitate pathogens.
c. there is a considerable delay between the initial exposure to an antigen and an effective response.
d. it only works against a particular antigen once.
e. many of the lymphocytes end up attacking the body’s own healthy cells.
Short answer: Write a concise answer to each of the following questions. Your answers should fit in the spaces provided. Each question is worth 6 points. When appropriate, you are welcome to use a diagram in your answer, but be sure all events and processes are made clear.
41. Describe a mechanism by
which water can be moved from the luminal or apical side of an epithelial layer
to the basolateral side, even if the overall osmotic concentration is the same
or higher on the luminal side.
42. Describe the mechanism by
which action potentials propagate along axons. You do not need to describe the
molecular details of voltage-gated sodium channel function, but you should
explain why action potentials normally propagate in only one direction.
43. Shown below is the strength of a stimulus affecting both a tonic and phasic receptor. On the lower graph, indicate the relative frequency of action potentials (by using vertical lines to indicate the action potentials) for each receptor type as the stimulus changes. You may also include notes explaining what is occurring if desired.
44. This question has two parts:
a. Provide the hormonal pathway and hormone-based feedback loops responsible for the control of thyroid hormone levels. You do not need to discuss the effects of thyroid hormones.
b.
Consider an individual who can no longer produce receptors for the
hormone that stimulates the thyroid gland. What would be the likely effects of
this condition on the level of each hormone in the pathway?
45. Describe the mechanism of
excitation-contraction coupling in a muscle, from the point at which
neurotransmitter is released by the terminal of the motor neuron to the point
at which calcium begins entering the myofibrils.
46. What observation did
Starling make with his “Law of the Heart,” and what is the physiological
mechanism underlying this observation?
47.
What is the bicarbonate buffering system, and how does it relate to the levels
of CO2 that are maintained in the alveoli?
48. Provide a list of both the short term (acute) and long term (slower or delayed) responses to a loss of blood. You do not need to indicate the pathways involved in bringing about these responses. What variable is being regulated by these responses?
49.
Describe the events in the uterus during the uterine cycle, including
the hormones that directly control these events. You do not need to
discuss the entire hormonal pathway involved in the menstrual cycle or events
in the ovary!
50. List the major events
associated with the inflammatory response, other than tissue repair. For each
item, provide a description of a few sentences. (Note that I am not
referring simply to the symptoms of inflammation – rugor, turgor,
calor, and dolor – although these do result from the events
you are describing.)
Extra credit question – To be announced. 4 points. Answer on reverse.