| Biology 449 - Animal Physiology | Spring 2006 |
200 points total
Answers in italics
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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 3 points.
1. Which of the following would not be classified as a physiologically regulated variable? (Hint: Think carefully about what is meant by “regulated” in this context.)
a. Blood calcium levels
b. Blood pH levels
c. Body temperature
d. Heart rate
e. Total extracellular fluid volume
2. In an investigation into renal function, you find that whenever extra-cellular potassium levels decrease, the level of a newly identified compound in the blood increases. This compound has a chemical structure similar to cholesterol. If you inject a dose of the compound into someone, less potassium appears in his urine. Based on this information and your knowledge of physiology, the compound is probably acting as a(n) ____________ in a negative feedback loop.
a. sensor
b. integrating center
c. efferent pathway
d. effector
e. regulated variable
3. Consider two solutions separated by a semi-permeable membrane. Solution A contains 1.0M NaCl, while solution B contains 1.0M KCl. The membrane is permeable to water and Na+ only. If you wished to keep Na+ from diffusing from solution A to solution B, which of the following strategies would likely be most effective?
a. Making the membrane permeable to K+.
b. Making the membrane permeable to Cl-.
c. Making the membrane impermeable to water.
d. Adding additional KCl to solution B.
e. Creating a positive charge on the B side of the membrane.
4. In a neuron, action potentials are usually seen in the
a. axon.
b. dendrites.
c. soma.
d. Two of the above.
e. All of the above.
5. The main difference between the Nernst and Goldman equations is
a. the Nernst equation considers only one ion, the Goldman more than one.
b. the Nernst equation does not consider the permeability of the membrane to ion(s), while the Goldman does.
c. the Nernst equation does not consider the valance of the ion(s), while the Goldman does.
d. Two of the above. (a and b)
e. All of the above.
6. Consider an axon to which two substances have been applied – one of these prevents the inactivation gates of the voltage-gated sodium channels from closing, while the other blocks the opening of voltage-gated potassium channels. If the membrane is depolarized above threshold potential, what would be the expected outcome?
a. no further increase in potential would take place, and the membrane would slowly return to normal resting potential.
b. the membrane would rapidly depolarize and stay depolarized indefinitely.
c. the membrane would rapidly depolarize and then slowly return to normal resting potential.
d. the membrane would rapidly depolarize and then rapidly return to normal resting potential.
e. the membrane would rapidly depolarize and then rapidly hyperpolarize, before returning to normal resting potential.
7. The release of neurotransmitter from a presynaptic neuron depends on the action of
a. ligand-gated calcium channels.
b. voltage-gated calcium channels.
c. ligand-gated sodium channels.
d. voltage-gated sodium channels.
e. G-proteins.
8. In order to be detected by the sensory system, an environmental variable must ultimately bring about
a. a change in cell membrane potential.
b. mechanical deformation of the cell membrane.
c. activation of ligand-gated ion channels.
d. activation of G-protein complexes.
e. the up- or down-regulation of mRNA synthesis.
9. Sensory cells that show rapid adaptation to a change in stimulus intensity are referred to as
a. mechanoreceptors.
b. nociceptors.
c. proprioceptors.
d. phasic receptors.
e. tonic receptors.
10. The number of different types of receptors in the olfactory system of mammals is
a. about five.
b. about a dozen.
c. about a hundred.
d. about a thousand.
e. millions.
11. The transduction of sound from vibrations to action potentials in the mammalian ear occurs in/at the
a. tympanic membrane
b. middle ear.
c. oval window.
d. organ of Corti.
e. round window.
12. A neurohormone is a chemical messenger that
a. affects the central nervous system.
b. affects peripheral neurons.
c. is released by a special class of neurons.
d. triggers the release of other hormones.
e. is released in response to other hormones.
13. The presence of Ca2+ in a sarcomere is normally necessary for cross-bridge cycling to occur because
a. Ca2+ causes tropomyosin to move away from the myosin binding sites on actin.
b. Ca2+ activates the myosin binding sites on actin.
c. Ca2+ activates myosin ATPase.
d. Ca2+ allows myosin to dissociate from actin after its power stroke.
e. The presence of Ca2+ is not normally necessary for cross-bridge cycling to occur.
14. If we say a muscle is shortening, which of the following will normally be occurring?
a. The muscle’s length is decreasing.
b. The muscle is producing force.
c. The muscle is exhibiting cross-bridge cycling.
d. Two of the above.
e. All of the above.
15. A tetanic contraction in a muscle results from
a. a single, short action potential.
b. a single extended action potential.
c. two action potentials.
d. multiple action potentials at high frequency (> 10 per second).
e. multiple action potentials at low frequency (< 1 per second).
16. The muscle fibers in a single motor unit of a human
a. are all the same fiber type.
b. are innervated by multiple neurons.
c. are activated in sequence, with new fibers initiating contracting as old ones fatigue.
d. are fused together into a single super-cell.
e. Two of the above.
17. During a heartbeat, the atrioventricular valves open when
a. the blood pressure in the atria first exceeds pressure in the ventricles.
b. the blood pressure in the ventricles first exceeds pressure in the atria.
c. the blood pressure in the arteries first exceeds pressure in the ventricles.
d. the blood pressure in the ventricles first exceeds pressure in the arteries.
e. There are no atrioventricular valves.
18. A number of different mechanisms can bring about an increase in the stroke volume of the mammalian heart. One thing all of these mechanisms have in common is that
a. they increase the volume of blood in the heart at the start of systole.
b. they are triggered by the sympathetic nervous system.
c. they are triggered by the parasympathetic nervous system.
d. they involve chemical messengers.
e. they increase the force of contraction by the ventricles.
19. In comparison to all capillaries combined, the aorta has
a. the same blood flow per minute, higher blood velocity and higher blood pressure.
b. higher blood flow per minute, higher blood velocity and higher blood pressure.
c. higher blood flow per minute, the same blood velocity and higher blood pressure.
d. the same blood flow per minute, higher blood velocity and the same blood pressure.
e. higher blood flow per minute, higher blood velocity and the same blood pressure.
20. One of the effects of emphysema is to make the lungs less compliant (that is, less stretchable and thus more resistant to expansion). At the end of a two liter inspiration, how would the intrapleural pressure of an individual with this disease compare to that of a healthy person?
a. The emphysematic would have a lower (more negative) intrapleural pressure than the healthy person.
b. The emphysematic would have a higher (less negative) intrapleural pressure than the healthy person.
c. The emphysematic would have the same intrapleural pressure as the healthy person.
d. The intrapleural pressure in the emphysematic would become positive.
e. Mr. T says: “Smoking is for fools!”
21. Breathing through a snorkel or other tube effectively increases a person’s anatomical dead space. If a person were snorkeling and the resulting total dead space (true anatomical + snorkel) was 300 ml, what would be the effect on the alveolar ventilation rate?
a. It would increase by about 100%.
b. It would decrease by about 40%.
c. It would decrease by about 50%.
d. It would be reduced to zero.
e. It is impossible to say without additional information.
22. In comparison to oxygen and carbon dioxide partial pressures in the alveoli, partial pressures in systemic arterial blood are
a. lower for oxygen and higher for carbon dioxide.
b. lower for oxygen and lower for carbon dioxide.
c. higher for oxygen and lower for carbon dioxide.
d. higher for oxygen and higher for carbon dioxide.
e. about the same in both locations for both gases.
23. The regulation of CO2 in the bloodstream and alveoli depends on the detection of which of the following by peripheral and central chemoreceptors?
a. CO2
b. H+
c. HCO3-
d. H2O
e. O2
24. Which of the following is not associated with the gastrointestinal tract?
a. Absorption of food
b. Digestion of food
c. Excretion of waste products
d. Motility
e. All of the above are associated with the GI tract.
25. Which of the following statements about digestive enzymes is true?
a. Amylase is activated by saliva.
b. Trypsin is activated by enterokinase.
c. Lipases are activated by bile salts.
d. Two of the above are true.
e. All of the above are true.
26. During the post-absorptive phase, the switch to fatty acid metabolism seen in most tissues is triggered directly by
a. increasing insulin levels.
b. decreasing insulin levels.
c. increasing glucagon levels.
d. decreasing glucagon levels.
e. decreasing glucose levels.
27. In healthy humans, the rate of glomerular filtration is roughly
a. 1 ml/min.
b. 10 ml/min.
c. 100 ml/min.
d. 1000 ml/min.
e. 10,000 ml/min.
28. One substance that is normally completely reabsorbed in the proximal tubule of the nephron is
a. glucose.
b. sodium.
c. urea.
d. water.
e. More than one of the above is completely reabsorbed in the proximal tubule.
29. In a person lacking an adrenal gland and thus unable to produce aldosterone, increased renin release would be able to bring about
a. an increase in sodium reabsorption but not blood pressure.
b. an increase in blood pressure but not sodium reabsorption.
c. an increase in both sodium reabsorption and blood pressure.
d. an increase in neither sodium reabsorption nor blood pressure.
e. tuberculosis.
30. Which of the following does not tend to cause a drop in arterial blood pressure?
a. a decrease in heart rate.
b. a decrease in stroke volume.
c. a decrease in blood volume.
d. a decrease in vasoconstriction.
e. All of the above tend to cause a drop in blood pressure.
31. Which of the following is a human secondary sexual characteristic that results from the presence of estrogen?
a. Appearance of the oviducts.
b. Appearance of pubic and axillary hair.
c. Development of the breasts.
d. Painted fingernails.
e. Two of the above.
32. In males, the highest levels of testosterone are found in the
a. bloodstream.
b. brain.
c. interstitial fluid.
d. prostate gland.
e. testes.
33. In males, luteinizing hormone directly promotes activity of the
a. Leydig cells.
b. Sertoli cells.
c. spermatogonia.
d. spermatocytes.
e. spermatozoa.
34. Spermatozoa develop from __________ cells and are supported by __________ cells during this process.
a. Leydig … Sertoli
b. Sertoli … Leydig
c. Leydig … spermatogonia
d. spermatogonia … Leydig
e. spermatogonia … Sertoli
35. The different components that make up semen are mixed together in which part of a male’s reproductive tract?
a. Epididymus
b. Ejaculatory duct
c. Seminal vesicle
d. Urethra
e. Vas deferens
36. In men, erection of the penis is initiated by increased activity of the ___________ and ejaculation is initiated by increased activity of the ___________.
a. parasympathetic nervous system … parasympathetic nervous system
b. parasympathetic nervous system … sympathetic nervous system
c. parasympathetic nervous system … somatic nervous system
d. sympathetic nervous system … parasympathetic nervous system
e. sympathetic nervous system … sympathetic nervous system
37. In human females, oocytes begin the process of meiosis
a. during fetal development.
b. shortly after birth.
c. at the onset of puberty.
d. immediately prior to ovulation.
e. upon fertilization.
38. During the follicular phase of the menstrual cycle, theca cells
a. are stimulated by follicle stimulating hormone.
b. produce androgens.
c. produce estrogen.
d. produce inhibin.
e. are not present.
39. In women, a significant portion of the endometrial layer of the uterus dies each month in direct response to
a. glucose insufficiency.
b. internal timing mechanisms.
c. infection by microorganisms.
d. lack of blood supply.
e. thickening of the cervical mucus.
40. During pregnancy in mammals, estrogen and progesterone are produced
a. first by the corpus luteum, then by the placenta.
b. first by the trophoblast, then by the corpus luteum.
c. by the corpus luteum throughout.
d. by the trophoblast and then the placenta.
e. Estrogen and progesterone levels are low during pregnancy