4. All of the Following Statements About Neurotransmitters Are Generally True EXCEPT
1.
Questions 2-3
2.
3.
4. All of the following statements about neurotransmitters are generally true EXCEPT:
(A) They may cause depolarization or hyperpolarization of the postsynaptic membrane.
(B) They are actively transported across the synaptic cleft.
(C) They may be enzymatically degraded at the postsynaptic membrane.
(D) They bind to specific receptors on the postsynaptic membrane.
5. In mammals, a decrease in body temperature results in which of the following responses?
(A) Release of thyroxine decreases the rate of metabolism.
(B) Blood vessels close to the surface of the skin constrict.
(C) Vessels in deep muscles constrict so increased secretion of epinephrine restricts the amount of sugar released into the circulatory system.
(D) The adrenal glands increase the release of acetylcholine into the circulatory system.
6. The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?
(A) During labor, the fetus exerts pressure on the uterine wall, inducing the production of oxytocin, which stimulates uterine wall contraction. The contractions cause the fetus to further push on the wall, increasing the production of oxytocin.
(B) After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.
(C) At high elevation, atmospheric oxygen is more scarce. In response to signals that oxygen is low, the brain decreases an individual’s rate of respiration to compensate for the difference.
(D) A transcription factor binds to the regulatory region of a gene, blocking the binding of another transcription factor required for expression.
7.
8. Which of the following is LEAST likely to result in a release of epinephrine (adrenaline) from the adrenal glands?
- Competing in an athletic event
- Going out on a first date
- Falling asleep during a lecture
- Swimming in a very cold pool
9. The diagram to the right represents
a. the cell-mediated response.
b. the humoral response.
c. helper T-cell antigen presentation.
d. the innate response.
10. The molecules indicated by letter C are
a. antibodies.c. antigens.
b. receptors.d. pathogens.
11. At what point(s) are the Na/K pump working?
a. 1 onlyb. 1 and 2c. 1, 3 and 4d. 1, 2, 3, and 4
12. At what point(s) do the sodium gates open?
a. 1 onlyb. 2 onlyc. 2 and 3d. 4 only
13. At what point(s) do the potassium gates open?
a. 1 onlyb. 1 and 2 c. 3 onlyd. 3 and 4
14. Which of the following is a physiological response that would occur at point 3?
a. Insulin would break glucose down into carbon dioxide.
b. Liver cells would take in glucose to store as glycogen.
c. Muscle cells would break down glycogen and release glucose into the bloodstream.
d. Heart rate would increase to move glucose around the body quicker.
15. Which of the following would result if the sodium-potassium pump of a neuron were inoperative?
(A)The movement of chloride ions would produce an action potential.
(B)An impulse would travel from the axon to the dendrites of the neuron.
(C)The rate of transmission of the impulse would greatly increase.
(D)An action potential would not occur.
16. Which of the following is most effective in lowering the body temperature of a mammal?
(A)Involuntary contraction of skeletal muscles
(B)Increased epinephrine (adrenaline) secretion
(C)Increased flow of blood to the skin
(D)Increased metabolic activity
17. Which of the following is most directly influenced by antidiuretic hormone (ADH)?
(A)The rate of glomerular filtration
(B)Reabsorption of water from the collecting duct
(C)Reabsorption of sodium ions from the distal convoluted tubule
(D)Secretion of potassium and hydrogen ions into the proximal convoluted tubule
18. Structures found in layer 7 function to
(A)change the shape of the cornea
(B)focus an image on the retina
(C)transmit neural impulses from the eye to the brain
(D)determine the color of the eye
19. This structure is a dendrite of a sensory neuron.
20. This structure is an axon of an interneuron (association neuron).