human physic human physic bio chem test ready stuff of test

7/23/2019 human physic human physic bio chem test ready stuff of test

http://slidepdf.com/reader/full/human-physic-human-physic-bio-chem-test-ready-stuff-of-test 1/36

6

Student: ___________________________________________________________________________

1. Which of the following is/are functions of the human nervous system?A.

receiving, storing, and processing information on the internal and external environments

B.

bringing about changes in physiology and/or behavior to ensure optimal functions of homeostaticmechanisms

C. secretion of hormonesD. coordination of movementE. All of the choices are correct.

2. Which is not true of myelin?A. It is a fatty membranous sheath.B. It is formed by glial cells.

C. It influences the velocity of conduction of an electrical signal down an axon.D.

It covers all parts of the neuron, including the axon, cell body, and dendrites.

3. Which of the following is not true about axon transport?A. It refers to the passage of materials from the cell body of a neuron to the axon terminals.B. It refers to the passage of materials from axon terminals to the cell body of a neuron.C. It refers to the transport of materials from the inside to the outside across the axonal membrane.D. It is especially important for maintaining the integrity of neurons with long axons.

4. Which is FALSE about neurons?A. A given neuron can be either a presynaptic neuron or a postsynaptic neuron.B. An individual neuron can receive information from multiple other neurons.C. An individual neuron can transmit information to multiple other neurons.D. A neuron can simultaneously release more than one type of neurotransmitter.E. A neuron receives information on its axons and delivers it to other neurons through its dendrites.

5. Which of the following is not true of glial cells?A. They form the myelin for axons.B. Neurons outnumber glial cells 10 to 1 in the nervous system.C. They deliver fuel molecules to neurons and remove the waste products of metabolism.D. They are important for the growth and development of the nervous system.E. They regulate the composition of the extracellular fluid in the CNS.

6. The difference in electrical charge between two points:A. is called the potential difference between those points.B. is called the diffusion potential between those points.C.

is called the the current, and is expressed in the units of millimoles.

D. is the same for all ions.



7. According to the equation expressed as Ohm's law, which of these would cause the greatest increase incurrent?A. doubling both voltage and resistanceB. reducing both voltage and resistance by halfC. doubling voltage and reducing resistance by halfD. reducing voltage by half and doubling resistanceE. quadrupling both voltage and resistance

8. Compartments A and B are separated by a membrane that is permeable to K+ but not to Na+ or Cl-. Attime zero, a solution of KCl is poured into compartment A and an equally concentrated solution of NaClis poured into compartment B. Which would be true once equilibrium is reached?A. The concentration of Na+ in A will be higher than it was at time zero.B. Diffusion of K+ from A to B will be greater than the diffusion of K+ from B to A.C. There will be a potential difference across the membrane, with side B negative relative to side A.D. The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction.E. The concentration of Cl- will be higher in B than it was at time zero.

9. Which is TRUE about the resting membrane potential?A. It requires very few ions to be distributed unevenly.B. It has the same value in all cells.

C. It is oriented so that the cell's interior is positive with respect to the extracellular fluid.D. Only nerve and muscle cells have a potential difference across the membrane at rest.E. It is not altered by changing concentration gradients of permeating ions.

10. Which is TRUE about typical, resting neurons?A. The plasma membrane is most permeable to sodium ions.B. The concentration of sodium ion is greater inside the cell than outside.C. The permeability of the plasma membrane to potassium ions is much greater than its permeability to

sodium ions.

D. The plasma membrane is completely impermeable to sodium ions.E. The plasma membrane is completely impermeable to potassium ions.

11. The membrane potential of most neurons at rest is:A. equal to the equilibrium potential for potassium.B. equal to the equilibrium potential for sodium.C.

slightly more negative than the equilibrium potential of potassium ion.

D.

more positive than the equilibrium potential for potassium.

E.

more positive than the equilibrium potential for sodium.

12. The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane:A. favors its movement into the cell at the resting membrane potential.B. favors its movement out of the cell at the resting membrane potential.C. is equal and opposite to the electrical potential acting on Na+ at the resting membrane potential.D. Is in the same direction as the diffusion potential due to the concentration gradient for K+.

E. favors movement of Na

+

in the opposite direction as the electrical potential acting on Na

+

at the restingmembrane potential.



13. Which would result from an increase in the extracellular concentration of K+ above normal?A. depolarization of resting nerve cellsB. hyperpolarization of resting nerve cellsC. The potassium equilibrium potential of nerve cells would become more negative.D. The sodium equilibrium potential would become less positive.

14.

Which is TRUE about the Na

+

, K

+

ATPase pump in neurons?

A.

It generates a small electrical potential such that the inside is made negative with respect to theoutside.

B.

It maintains a concentration gradient for K+ such that diffusion forces favor movement of K+ into thecell.

C. It maintains an electrical gradient at the equilibrium potential of K+.D. It transports equal numbers of sodium and potassium ions with each pump cycle.E. It pumps 3 Na+ ions into the cell for every 2 K+ ions it pumps out.

15. Which of these would occur if the concentration of ATP were depleted in a typical nerve cell?A. Resting membrane potential would become more negative.B. Resting membrane potential would become less negative.C. The concentration gradient for Na+ would remain the same.D. The resting membrane potential would eventually become positive inside with respect to outside.E. There would be no change in the resting membrane potential.

16. Which is FALSE about the equilibrium potential of a given ion across a membrane?A. It is a function of the concentration of that ion on both sides of the membrane.B. It is the potential at which there is no net movement of that ion across the membrane.C.

It is the potential difference across the membrane at which an electric force favoring movement of theion in one direction is equal in magnitude and opposite in direction to the diffusion force provided by theconcentration difference of the ion across the membrane.

D.

A permeable ion will move in the direction that will tend to bring the membrane potential toward thation's equilibrium potential.

E.

An anion that is in higher concentration inside the cell than outside the cell will have a negativeeqilibrium potential.

17. The equilibrium potential of K+ ions in nerve cells is about -90 mV. The membrane potential of typicalnerve cells at rest is -70 mV. ThereforeA.

Increasing the permeability of a resting neuronal membrane to K+ will make the membrane potentialmore negative inside with respect to outside.

B. In resting neurons, there is a net diffusion of K+ into the cell.C.

changing the resting membrane potential of a neuron to -80 mV would increase K+ diffusion rate outof the cell.

D.

potassium is the only permanent ion at rest.

E.

there must be another permanent ion with an equilibrium potential more negative than -90 mV.



18. Which of the following statements concerning the permeability of a typical neuron membrane at rest istrue?A. The permeability to Na+ is much greater than the permeability to K+.B.

All of the K+ channels in the membrane are open.

C. The voltage-gated Na+ channels are in the inactivated state.D. Most of the voltage-gated Na+ channels are in the closed state.

E. There is equal permeability to Na+ and K+.

19. Which is NOT an example of a graded potential?A. a receptor potential in a sensory receptor cellB. a depolarizing excitatory postsynaptic potential (EPSP)C. a hyperpolarizing inhibitory postsynaptic potential (IPSP)D. a depolarizing pacemaker potentialE. a depolarizing action potential

20. An action potential in a neuronal membrane differs from a graded potential in that:A. an action potential requires the opening of Ca2+ channels, whereas a graded potential does not.B.

an action potential is propagated without decrement, whereas a graded potential decrements withdistance.

C. an action potential has a threshold, whereas a graded potential is an all-or-none phenomenon.D.

movement of Na+ and K+ across cell membranes mediate action potentials, while graded potentials donot involve movement of Na+ and K+.

E. action potentials vary in size with the size of a stimulus, while graded potentials do not.

21. A threshold stimulus applied to an excitable membrane is one that is just sufficient to:A. trigger an excitatory postsynaptic potential.B. cause a change in membrane potential.C. trigger an action potential.D. be conducted to the axon hillock.

E. depolarize a dendrite.

22. Which must happen in order for an action potential to begin?A. The membrane potential must be at the Na+ equilibrium potential.B. Na+ influx must exceed K+ efflux.C. The membrane must be out of the relative refractory period.D. Na+ channels must all be inactivated.E. Multiple inhibitory postsynaptic potentials (IPSPs) must summate.

23. Which describes the response of the voltage-gated channels when an axon is stimulated to threshold?A. K+ channels open before the Na+ channels.

B. Na

+

channels are activated and then inactivated.C. K+ channels open at the same time as the Na+ channels.D. K+ channels are opened when Na+ binds to the channel.E. K+ influx causes Na+ channels to inactivate.

24. During the rising (depolarizing) phase of a neuronal action potential,A. PK+ becomes much greater than PNa+. B. PNa+ becomes much greater than PK+. C. PK+ is the same as PNa+. D. Na+ efflux (flow out of the cell) occurs.E. K+ flows rapidly into the cell.



25. Which is true about neuronal membrane electrical and concentration gradients at the peak of the actionpotential?A. The electrical gradient is in a direction that would tend to move K+ out of the cell.B.

The concentration gradient for K+ is in a direction that would tend to move it into the cell.

C. The concentration gradient for K+ greatly increases compared to at rest.D. The concentration gradient for Na+ is in a direction that would tend to move it out of the cell.

E. The electrical gradient for Na+ is in a direction that would tend to move it into the cell.

26. Which is most directly responsible for the falling (repolarizing) phase of the action potential?A. Voltage-gated Na+ channels are opened.B. The Na+, K+ pump restores the ions to their original locations inside and outside of the cell.C. The permeability to Na+ increases greatly.D. ATPase destroys the energy supply that was maintaining the action potential at its peak.E. The permeability to K+ increases greatly while that to Na+ decreases.

27. Why are action potentials sometimes described as being "all-or-none" in character?A. The rate of propagation of an action potential down an axon is independent of stimulus strength.B. They are associated with an absolute refractory period.C.

A supra-threshold stimulus is required to stimulate an action potential during the relative refractoryperiod.

D.

An action potential occurs whenever a suprathreshold stimulus occurs, and its amplitude does not varywith the size of a stimulus.

E. Action potentials are always the same size, even when ion gradients vary in size.

28. Which of the following statements about the phases of a neuronal action potential is true?A.

During the after-hyperpolarization phase, the permeability of the membrane to sodium ions is greaterthan its permeability to potassium ions.

B.

During the after-hyperpolarization phase, the permeability of the membrane to potassium ions is greaterthan its permeability at rest.

C.

During the repolarizing phase, the permeability of the membrane to sodium ions is greater than itspermeability to potassium ions.

D. Potassium channels inactivate during the depolarization phase.E. Repolarizing to negative membrane potentials causes the sodium channels to inactivate.

29. Which of the following statements about the refractory period of a membrane is true?A.

The absolute refractory period refers to the period of time during which another action potential cannotbe initiated in that part of the membrane that is undergoing an action potential, no matter how great thestrength of the stimulus.

B.

The relative refractory period refers to the period of time during which another action potential canbe initiated in that part of the membrane that has just undergone an action potential if a stronger than

normal stimulus is applied.C.

The refractory period prevents the action potential from spreading back over the part of the membranethat just underwent an action potential.

D.

The refractory period places an upper limit on the frequency with which a nerve cell can conductaction potentials.

E. All of the above choices are correct.

30. The relative refractory period of an axon coincides with the period ofA. activation and inactivation of voltage-dependent Na+ channels.B. Na+ permeability that is greater than that during the depolarization phase.C. increased K+ flux into the cell.D. increased K+ permeability of the cell.E. Increased Na+ flux through K+ channels.



31. Neuronal axons typically have abundantA. voltage-gated channels for Na+ that open in response to depolarization.B. voltage-gated channels for K+ that open in response to hyperpolarization.C. receptor-mediated channels for Na+.D. receptor-mediated channels for K+.E. voltage-gated channels for Ca2+.

32. Which of the following statements regarding action potentials generated in a neuronal membrane is not true?A. Action potentials travel decrementally down the membrane.B. An action potential generates a new action potential in an adjacent area of membrane.C.

An action potential generates a local current that depolarizes adjacent membrane to threshold potential.

D. Action potentials are usually initiated at the initial segment of a neuron.E.

An action potential generated by a threshold stimulus is the same size as one generated by a supra-threshold stimulus.

33. Which of the following statements concerning the properties of action potentials is true?A. The rate of propagation of an action potential down an axon is independent of stimulus strength.B. Action potentials can undergo summation.

C. A supra-threshold stimulus can stimulate an action potential during the absolute refractory period.D. Action potentials generally propagate from the axon terminal toward the initial segment.E. Increasing the size of a stimulus will increase the amplitude of an action potential.

34. How is the strength of a stimulus encoded by neurons?A. by the size of action potentialsB. by the frequency of action potentialsC. by the duration of action potentialsD. by whether the action potential peak is positive or negative

35. Which of the following statements concerning the rate of action potential propagation is true?

A. It is faster in small-diameter axons than in large-diameter axons.B. It is faster for a strong stimulus than for a weak one.C. It is faster in myelinated axons than in nonmyelinated axons.D. It is faster in the dendrites than in the axon.E. It occurs at the same rate in all axons, regardless of their diameter.

36. An action potential does not re-stimulate the adjacent membrane that was previously depolarized because

A. stimulation is inhibited by the myelin sheath.B. it is impossible for an action potential to be propagated along an axon toward the nerve cell body.C. the resting membrane potential of the axon is too positive.D. the resting membrane potential of the axon is too negative.

E. that area of the membrane is in the absolutely refractory period.

37. The regions of axon membrane that lie between regions of myelin are theA. islets of Langerhans.B. nodes of Ranvier.C. synaptic membranes.D. glial cells.E. dens of iniquities.



38. Which is FALSE about interneurons?A. They receive synaptic input from other other neurons in the CNS.B. They sum excitatory and inhibitory synaptic inputs.C. They deliver synaptic input on other neurons.D.

They make synapses on effector organs in the PNS.

E. They can transmit information between afferent neurons and efferent neurons.

39. Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response tothe arrival of an action potential in the axon terminal.A. K+ B. Na+ C. Ca2+ D. ATPE. Cl-

40. The main role of calcium ions at chemical synapses is toA. depolarize the axon terminal of the presynaptic cell.B.

bind to neurotransmitter receptors on the postsynaptic cell.

C. cause fusion of synaptic vesicles with the plasma membrane of the axon terminal.D. interfere with IPSPs in the postsynaptic cell.E. diffuse across the synaptic space and enter the postsynaptic cell.

41. At an excitatory chemical synapse between two neurons,A. there is increased permeability of the postsynaptic cell to both Na+ and K+.B. a small hyperpolarization of the postsynaptic membrane occurs when the synapse is activated.C.

an action potential in the presynaptic neuron always causes an action potential in the postsynaptic

neuron.D. excitation occurs because K+ enters the postsynaptic cell.E. action potentials spread through gap junctions between cells.

42. An inhibitory postsynaptic potential:A.

is produced by simultaneous increases in permeability to both Na+ and K+.

B. occurs when a ligand-gated ion channel increases its permeability to K+.C. is a small depolarization in a postsynaptic cell.D. can be summed with other IPSPs to trigger an action potential in the postsynaptic cell.

E. is produced by an increase in permeability to only Na

+

.

43. Which of the following statements about EPSPs is false?A. They are produced by the opening of chemically-gated sodium channels.B. They transmit signals over relatively short distances.C.

They depolarize postsynaptic cell membranes.

D. They are able to summate.E. They are always the same amplitude.



44. An EPSP:A. is a direct result of the opening of ligand-gated channels permeable to both Na+ and K+ ions.B. is a direct result of the opening of voltage-gated channels permeable to both Na+ and K+ ions.C. stabilizes the membrane to remain at its resting potential.D. opens voltage-gated Ca2+ channels in the presynaptic membrane.E. occurs when voltage-gated Cl- channels open in a postsynaptic cell membrane.

45. Which best describes temporal summation?A.

A synapse is stimulated a second time before the effect of a first stimulus at the synapse hasterminated.

B. It only refers to addition of EPSPs.C. Two synapses on different regions of a cell are stimulated at the same time.D. It always brings a postsynaptic cell to threshold.E. The size of an EPSP depends on the size of the stimulus.

46.

A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. Stimulation of neuron Xcauses the postsynaptic neuron to depolarize by 0.5 mV. When X and Y are stimulated simultaneously,the postsynaptic neuron depolarizes by 1 mV. When X and Z are stimulated simultaneously, however,there is no change in the membrane potential of the postsynaptic neuron. What is most likely true aboutpresynaptic neurons Y and Z?

A. They are both excitatory.B. They are both inhibitory.C. Y is excitatory and Z is inhibitory.D. Z is excitatory and Y is inhibitory.

47.

A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. When X and Y arestimulated simultaneously and repeatedly, the postsynaptic neuron reaches threshold and undergoesan action potential. When X and Z are stimulated simultaneously, however, there is no change in themembrane potential of the postsynaptic neuron. The simultaneous stimulation of X and Y is an exampleof

A. temporal summation.B. presynaptic inhibition.C. spatial summation.D. neuronal divergence.E. presynaptic facilitation.

48. Which is TRUE about the initial segment of an axon?A. Its threshold potential is more positive than that of the cell body and dendrites.B. Its threshold potential is more negative than that of the cell body and dendrites.C.

Synapses far from the initial segment are more effective in influencing whether an action potential willbe generated in the axon than are synapses close to the initial segment.

D. It is the region where neurotransmitter vesicles are docked and ready to be released by exocytosis.E. It can only conduct graded potentials because it lacks voltage-gated Na+ channels.



49. A presynaptic synapse:A. is a synapse between an axon terminal and a dendrite that can be either excitatory or inhibitory.B. is a synapse between an axon terminal and another axon's terminal that can be either excitatory or

inhibitory.

C. is any synapse onto a cell body, and they can be either stimulatory or inhibitory.D. is a synapse between an axon terminal and a dendrite of the same cell, which is always inhibitory.

E. is a synapse between an axon terminal and another axon terminal that is always inhibitory.

50. Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z.Which will occur when action potentials are stimulated in neuron X?A. Neuron Y will be inhibited from reaching the threshold to fire an action potential.B. The release of neurotransmitter by neuron Y will be inhibited.C.

The synapse between neurons Y and Z will be changed from an excitatory synapse to an inhibitoryone.

D. Neurons Y and Z will both be more likely to reach threshold and fire an action potential.E. Neurons Y and Z will both be less likely to reach threshold and fire an action potential.

51. Which of the following is not known to be an important neurotransmitter in the CNS?A. DopamineB. AcetylcholineC. MorphineD. GlutamateE. Substance P

52. Which of the following statements about acetylcholine is correct?A. Acetylcholine binds to nicotinic and muscarinic receptors.B. Acetylcholine binds to adrenergic receptors.C. Acetylcholine synthesis is catalyzed by acetylcholinesteraseD. Acetylcholine is the neurotransmitter released by most sympathetic postganglionic neurons.

E.

Acetylcholine is generally transported back into presynaptic nerve terminals without beingenzymatically degraded.

53. Which of the following statements regarding neurotransmitters is TRUE?A. Acetylcholine is broken down by enzymes present on postsynaptic cell membranes.B.

Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cellmembrane.

C. Catecholamines are the most abundant neurotransmitters in the central nervous system.D. Opiate drugs, such as morphine, are antagonists of a class of neurotransmitters called endorphins.E. Gamma-aminobutyric acid (GABA) is a major excitatory transmitter in the central nervous system.

54. Acetylcholine is the main neurotransmitter released by:A. preganglionic sympathetic neurons and cells of the adrenal medulla.B. cells of the adrenal medulla and postganglionic parasympathetic neurons.C. motor neurons and postganglionic sympathetic neurons.D. preganglionic sympathetic neurons and postganglionic sympathetic neurons.E. preganglionic sympathetic neurons and motor neurons.

55. Which of the following statements about norepinephrine is FALSE?A. Norepinephrine is a neurotransmitter.B. Norepinephrine binds to adrenergic receptors.C. Norepinephrine is a catecholamine.D. Dopamine is a precursor to norepinephrine.

E. Epinephrine is a precursor to norepinephrine.



56. Which of the following enzymes is important for the metabolism of catecholamines?A. Tyrosine hydroxylaseB. AcetylcholinesteraseC. Superoxide dismutaseD. HydrocortinaseE. Adenyl cyclase

57. Nicotine is:A. a cholinergic antagonist.B. a beta-adrenergic agonist.C. a cholinergic agonist.D. an alpha-adrenergic antagonist.E. a neurotransmitter.

58. Serotonin:A. acts as a neuromodulator.B. is a catecholamine neurotransmitter.C. is a neuropeptide.D. has an inhibitory effect on pathways that are involved in the control of muscles.E. has an excitatory effect on pathways that mediate sensations.

59. Alzheimer's disease is thought to involve primarily:A. loss of neurons that secrete or respond to catecholamines.B. loss of adrenergic neurons.C. loss of cholinergic neurons.D. loss of neurons that secrete or respond to dopamine.E. tumors that produce excess serotonin.

60. Which is one of the major inhibitory neurotransmittors in the CNS?A. GlutamateB. Dopamine

C. NorepinephrineD. Gamma-aminobutyric acid (GABA)E. Beta-endorphin

61. Which is one of the most abundant excitatory neurotransmittors in the CNS?A. GlutamateB. DopamineC. NorepinephrineD. Gamma-aminobutyric acid (GABA)E. Endorphin

62. The central nervous system includes the:

A. afferent nerves and spinal cord.B. efferent nerves and spinal cord.C. autonomic nervous system and the brain.D. brain stem and the autonomic nervous system.E. brain and spinal cord.

63. The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletalmuscle is called the:A. afferent nervous system.B. sympathetic nervous system.C. parasympathetic nervous system.

D. somatic motor nervous system.E. autonomic nervous system.



64. The region of the brain that is the most important control area for homeostatic regulation of the internalenvironment is:A. the thalamus.B. the hippocampus.C. the cerebrum.D. the cerebellum.E. the hypothalamus.

65. Which of the following kinds of neurons is not generally cholinergic?A. somatic motor neuronsB. postganglionic sympathetic neuronsC. postganglionic parasympathetic neuronsD. preganglionic sympathetic neuronsE. preganglionic parasympathetic neurons

66. Which of the following does NOT result from the binding of nicotine with nicotinic acetylcholinereceptors?A. a mild form of skeletal muscle paralysis that creates a more relaxed stateB. signal transmission at neuromuscular junctionsC. generation of excitatory signals within autonomic ganglia

D.the release of norepinephrine, dopamine, and epinephrine

E.

facilitation of the release of multiple neurotransmitters within the brain, including the "rewardpathway" involving dopamine

67. Drug X interferes with the action of norepinephrine at synapses. Which of the following mechanismswould not explain the effects of X?A. X inhibits synthesis of norepinephrine at the axon terminal.B. X inhibits norepinephrine release from the terminal.C. X blocks reuptake of norepinephrine by the terminal.

D. X is an adrenergic receptor antagonist.E. X stimulates the catabolism of norepinephrine.

68. Synthesis of neuropeptides differs from that of other neurotransmitters because it:A. takes place in the axon terminals of neurons.B. takes place in the cell bodies of neurons.C. takes place on ribosomes in the postsynaptic cell's membrane.D. uses amino acids as precursor molecules.E. only takes place at synapses outside the central nervous system.

69. Which best describes the reticular formation of the brain?

A. It is mainly involved in motor coordination and balance.B. It is the master endocrine gland of the brain.C. It is primarily responsible for visual perception.D.

It integrates information from all regions of the CNS, and incorporates the mechanisms that regulatesleep and wakefulness.

E. It is the primary synaptic relay station for sensory information entering the CNS.

70. The cerebellum:A. is important for coordinating body movement.B. is the gray matter covering the entire surface of the brain.C. is the same thing as the brain stem.D. is in the anterior portion of the brain, just above the eyes.

E. is one of the basal nuclei that is found deep inside the cerebrum.



71.

The ________________ is best described as "an interconnected group of brain structures including partsof the frontal lobe-cortex, temporal lobe, thalamus, and hypothalamus, that is associated with learning,emotional experience, and behavior?"

A. diencephalonB. cerebrum

C. limbic systemD. reticular formationE. cerebellum

72. Which is a FALSE statement about the cerebrospinal fluid?A. It has the same composition as blood plasma.B. It acts as a cushion for the brain and spinal cord.C. It is secreted by cells lining the ventricles of the brain.D. It circulates within and between brain ventricles and surrounds the spinal cord.E. It is in diffusion equilibrium with the extracellular fluid of the central nervous system.

73.

Which of the following is NOT characteristic of the sympathetic division of the ANS?

A. Preganglionic neurons tend to be long, with the ganglion located in or near the effector target tissue(s).B. Preganglionic neurons are short and synapse in ganglia located near the spinal cord.C. Preganglionic neurons release acetylcholine at synapses with postganglionic neurons.D. Postganglionic neurons release norepinephrine at their neuroeffector junctions.E. Postganglionic neuron cell bodies are located in the collateral chain ganglia (sympathetic trunk).

74. Postganglionic neuron cell bodies of the autonomic nervous system have which category of

neurotransmitter receptor?A. Adrenergic receptorB. Serotonin receptorsC. Muscarinic acetylcholine receptorsD. Nicotinic acetylcholine receptorsE. Dopamine receptors

75. A myelinated axon is shielded from direct contact with the extracellular fluid all along its length.True False

76. The lipid portion of a cell's plasma membrane constitutes a barrier to current.True False

77.

True False

Ions other than Na+, K+, and Cl- play no role in generating the resting membrane potential of a cell.

78. The maintenance of a resting potential in a neuron depends indirectly upon the functioning of the Na+,K+-ATPase pumps in the membrane.True False

79. A graded potential in a membrane results in an electric current along an adjacent area of membrane andthis current diminishes with distance from the site of the initial potential change.True False



80. During a hyperpolarizing graded potential, positively charged ions flow away from the site of the initialhyperpolarization on the outside of membrane and toward this site on the inside.True False

81. Because so many Na ions move into a cell during an action potential and so many K ions move out, nofurther action potentials can be generated in a given membrane until the Na, K-ATPase pumps can restorethe concentration gradient.True False

82. The Na+ and K+ channels that open during an action potential are voltage regulated, both opening inresponse to depolarization of the membrane.True False

83. SNARE receptor protein complexes in presynaptic neurons function as inhibitors of calcium transport todampen or reduce the amount of neurotransmitter vesicles which participate in exocytosis.True False

84. The action potential elicited by a supra-threshold stimulus is larger than one elicited by a thresholdstimulus.True False

85. The relative refractory period of an excitable membrane refers to the period of time during which nostimulus, however strong, will elicit a second action potential in the membrane.True False

86. The absolute refractory period of an excitable membrane roughly corresponds to the period when sodiumchannels are opening and inactivated.True False

87. Because all parts of a neuronal cell body have the same threshold, no one synapse on the cell is moreimportant than any other.True False

88. The frequency of action potentials in a postsynaptic cell is directly related to the degree of depolarizationof the postsynaptic cell.True False

89. Catecholamines are the most abundant neurotransmitters in the CNS.True False

90. Opioid drugs, such as morphine, are agonists of a class of neurotransmitters called endorphins.True False

91. The most common neurotransmitters for neuroeffector communication are dopamine and

acetylcholine.True False

92. Dorsal root ganglia contain the cell bodies of efferent neurons.True False

93. Spinal nerves are composed of the axons of both afferent and efferent neurons.True False

94. Although nerve cells in each cerebral hemisphere make connections with other cells in the samehemisphere, there is no crossover of information between the two hemispheres.True False

95. The cerebrum consists only of gray matter.

True False



96. The basal ganglia are important subcortical nuclei in the cerebrum.True False

97. The thalamus is the single most important control area for regulating the homeostasis of the internalenvironment.True False

98. The efferent division of the peripheral nervous system consists of the somatic nervous system and theautonomic nervous system.

True False

99. Preganglionic fibers of the parasympathetic division of the autonomic nervous system leave the CNS atthe level of the brainstem and sacral portions of the spinal cord.True False

100.Most of the parasympathetic ganglia lie in chains along the spinal cord called sympathetic trunks.True False

101.Responses made possible by motor signals transmitted by the parasympathetic nervous system tend to bedisplayed throughout the body simultaneously because there is much divergence of nerve pathways andclose anatomical association between presynaptic neurons and their ganglia as well as accessory activitywith the adrenal glands.True False

102.True False

The sympathetic division of the autonomic nervous system is arranged so that it acts largely as aunit, whereas the components of the parasympathetic division generally act as discreet, independentcomponents.

103."Dual innervation of effectors" refers to the innervation of the same effector organs by somatic andautonomic nerves.True False



6 Key

1. Which of the following is/are functions of the human nervous system?A.

receiving, storing, and processing information on the internal and external environments

B.

bringing about changes in physiology and/or behavior to ensure optimal functions of homeostaticmechanisms

C. secretion of hormonesD. coordination of movementE. All of the choices are correct.

Blooms: Level 1. Remember

Chapter - Chapter 06 #1

Learning Outcome: 06.01


Section: 06.01

Section: 06.15

Topic: Nervous System

2. Which is not true of myelin?

A. It is a fatty membranous sheath.B. It is formed by glial cells.C. It influences the velocity of conduction of an electrical signal down an axon.D.

It covers all parts of the neuron, including the axon, cell body, and dendrites.




Section: 06.01


3. Which of the following is not true about axon transport?A. It refers to the passage of materials from the cell body of a neuron to the axon terminals.B. It refers to the passage of materials from axon terminals to the cell body of a neuron.C. It refers to the transport of materials from the inside to the outside across the axonal membrane.

D. It is especially important for maintaining the integrity of neurons with long axons.

Blooms: Level 1. Remember Chapter - Chapter 06 #3


Section: 06.02


4. Which is FALSE about neurons?A. A given neuron can be either a presynaptic neuron or a postsynaptic neuron.B. An individual neuron can receive information from multiple other neurons.C. An individual neuron can transmit information to multiple other neurons.D. A neuron can simultaneously release more than one type of neurotransmitter.E. A neuron receives information on its axons and delivers it to other neurons through its dendrites.




Section: 06.01

Section: 06.02




5. Which of the following is not true of glial cells?A. They form the myelin for axons.B. Neurons outnumber glial cells 10 to 1 in the nervous system.

C. They deliver fuel molecules to neurons and remove the waste products of metabolism.D. They are important for the growth and development of the nervous system.E. They regulate the composition of the extracellular fluid in the CNS.



Section: 06.03


6. The difference in electrical charge between two points:A. is called the potential difference between those points.

B. is called the diffusion potential between those points.C.

is called the the current, and is expressed in the units of millimoles.

D. is the same for all ions.


Learning Outcome: 06.05 Section: 06.05


7. According to the equation expressed as Ohm's law, which of these would cause the greatest increasein current?A. doubling both voltage and resistanceB. reducing both voltage and resistance by halfC. doubling voltage and reducing resistance by half

D. reducing voltage by half and doubling resistanceE. quadrupling both voltage and resistance

Blooms: Level 2. Understand Chapter - Chapter 06 #7



8. Compartments A and B are separated by a membrane that is permeable to K+ but not to Na+ or Cl-.At time zero, a solution of KCl is poured into compartment A and an equally concentrated solution ofNaCl is poured into compartment B. Which would be true once equilibrium is reached?A. The concentration of Na+ in A will be higher than it was at time zero.B. Diffusion of K+ from A to B will be greater than the diffusion of K+ from B to A.C. There will be a potential difference across the membrane, with side B negative relative to side A.D. The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction.

E. The concentration of Cl- will be higher in B than it was at time zero.




9. Which is TRUE about the resting membrane potential?A. It requires very few ions to be distributed unevenly.

B. It has the same value in all cells.C. It is oriented so that the cell's interior is positive with respect to the extracellular fluid.D. Only nerve and muscle cells have a potential difference across the membrane at rest.E. It is not altered by changing concentration gradients of permeating ions.






10. Which is TRUE about typical, resting neurons?A. The plasma membrane is most permeable to sodium ions.B. The concentration of sodium ion is greater inside the cell than outside.C.

The permeability of the plasma membrane to potassium ions is much greater than its permeabilityto sodium ions.

D. The plasma membrane is completely impermeable to sodium ions.

E. The plasma membrane is completely impermeable to potassium ions.




11. The membrane potential of most neurons at rest is:A. equal to the equilibrium potential for potassium.B. equal to the equilibrium potential for sodium.C.

slightly more negative than the equilibrium potential of potassium ion.

D.

more positive than the equilibrium potential for potassium.

E.

more positive than the equilibrium potential for sodium.





12. The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane:A. favors its movement into the cell at the resting membrane potential.

B. favors its movement out of the cell at the resting membrane potential.C. is equal and opposite to the electrical potential acting on Na+ at the resting membrane potential.D. Is in the same direction as the diffusion potential due to the concentration gradient for K+.E.

favors movement of Na+ in the opposite direction as the electrical potential acting on Na+ at theresting membrane potential.




13. Which would result from an increase in the extracellular concentration of K+ above normal?A. depolarization of resting nerve cells

B. hyperpolarization of resting nerve cellsC. The potassium equilibrium potential of nerve cells would become more negative.D. The sodium equilibrium potential would become less positive.






14.

Which is TRUE about the Na+, K+ ATPase pump in neurons?

A. It generates a small electrical potential such that the inside is made negative with respect to theoutside.

B. It maintains a concentration gradient for K+ such that diffusion forces favor movement of K+ intothe cell.

C. It maintains an electrical gradient at the equilibrium potential of K+.D. It transports equal numbers of sodium and potassium ions with each pump cycle.E. It pumps 3 Na+ ions into the cell for every 2 K+ ions it pumps out.





15. Which of these would occur if the concentration of ATP were depleted in a typical nerve cell?A. Resting membrane potential would become more negative.B. Resting membrane potential would become less negative.

C. The concentration gradient for Na+ would remain the same.

D. The resting membrane potential would eventually become positive inside with respect to outside.E. There would be no change in the resting membrane potential.




16. Which is FALSE about the equilibrium potential of a given ion across a membrane?A. It is a function of the concentration of that ion on both sides of the membrane.B. It is the potential at which there is no net movement of that ion across the membrane.C.

It is the potential difference across the membrane at which an electric force favoring movementof the ion in one direction is equal in magnitude and opposite in direction to the diffusion force

provided by the concentration difference of the ion across the membrane.D.

A permeable ion will move in the direction that will tend to bring the membrane potential towardthat ion's equilibrium potential.

E.

An anion that is in higher concentration inside the cell than outside the cell will have a negativeeqilibrium potential.

Blooms: Level 2. Understand Chapter - Chapter 06 #16 Learning Outcome: 06.06

Section: 06.06 Topic: Nervous System



17. The equilibrium potential of K+ ions in nerve cells is about -90 mV. The membrane potential oftypical nerve cells at rest is -70 mV. ThereforeA

.

Increasing the permeability of a resting neuronal membrane to K+ will make the membranepotential more negative inside with respect to outside.

B. In resting neurons, there is a net diffusion of K+ into the cell.C. changing the resting membrane potential of a neuron to -80 mV would increase K+ diffusion rate

out of the cell.

D.

potassium is the only permanent ion at rest.

E.

there must be another permanent ion with an equilibrium potential more negative than -90 mV.

Blooms: Level 2. Understand

Chapter - Chapter 06 #17 Learning Outcome: 06.06

Section: 06.06


18. Which of the following statements concerning the permeability of a typical neuron membrane at rest istrue?A. The permeability to Na+ is much greater than the permeability to K+.B.

All of the K+ channels in the membrane are open.

C. The voltage-gated Na+ channels are in the inactivated state.D. Most of the voltage-gated Na+ channels are in the closed state.

E. There is equal permeability to Na+ and K+.




19. Which is NOT an example of a graded potential?A. a receptor potential in a sensory receptor cellB. a depolarizing excitatory postsynaptic potential (EPSP)C. a hyperpolarizing inhibitory postsynaptic potential (IPSP)D. a depolarizing pacemaker potentialE. a depolarizing action potential




20. An action potential in a neuronal membrane differs from a graded potential in that:A. an action potential requires the opening of Ca2+ channels, whereas a graded potential does not.B. an action potential is propagated without decrement, whereas a graded potential decrements with

distance.C. an action potential has a threshold, whereas a graded potential is an all-or-none phenomenon.D.

movement of Na+ and K+ across cell membranes mediate action potentials, while graded potentialsdo not involve movement of Na+ and K+.

E. action potentials vary in size with the size of a stimulus, while graded potentials do not.







21. A threshold stimulus applied to an excitable membrane is one that is just sufficient to:A. trigger an excitatory postsynaptic potential.B. cause a change in membrane potential.C. trigger an action potential.

D. be conducted to the axon hillock.E. depolarize a dendrite.




22. Which must happen in order for an action potential to begin?A. The membrane potential must be at the Na+ equilibrium potential.B. Na+ influx must exceed K+ efflux.

C. The membrane must be out of the relative refractory period.D. Na+ channels must all be inactivated.E. Multiple inhibitory postsynaptic potentials (IPSPs) must summate.




23. Which describes the response of the voltage-gated channels when an axon is stimulated to threshold?

A. K+ channels open before the Na+ channels.B. Na+ channels are activated and then inactivated.

C. K+ channels open at the same time as the Na+ channels.D. K+ channels are opened when Na+ binds to the channel.E. K+ influx causes Na+ channels to inactivate.




24. During the rising (depolarizing) phase of a neuronal action potential,A. PK+ becomes much greater than PNa+. B. PNa+ becomes much greater than PK+.

C. PK+ is the same as PNa+. D. Na+ efflux (flow out of the cell) occurs.E. K+ flows rapidly into the cell.




25. Which is true about neuronal membrane electrical and concentration gradients at the peak of the actionpotential?A. The electrical gradient is in a direction that would tend to move K+ out of the cell.

B.

The concentration gradient for K+ is in a direction that would tend to move it into the cell.

C. The concentration gradient for K+ greatly increases compared to at rest.D. The concentration gradient for Na+ is in a direction that would tend to move it out of the cell.E. The electrical gradient for Na+ is in a direction that would tend to move it into the cell.







26. Which is most directly responsible for the falling (repolarizing) phase of the action potential?A. Voltage-gated Na+ channels are opened.B. The Na+, K+ pump restores the ions to their original locations inside and outside of the cell.C. The permeability to Na+ increases greatly.D. ATPase destroys the energy supply that was maintaining the action potential at its peak.E. The permeability to K+ increases greatly while that to Na+ decreases.

Blooms: Level 1. Remember Chapter - Chapter 06 #26 Learning Outcome: 06.07

Section: 06.07


27. Why are action potentials sometimes described as being "all-or-none" in character?A. The rate of propagation of an action potential down an axon is independent of stimulus strength.B. They are associated with an absolute refractory period.C. A supra-threshold stimulus is required to stimulate an action potential during the relative refractory

period.D.

An action potential occurs whenever a suprathreshold stimulus occurs, and its amplitude does notvary with the size of a stimulus.

E. Action potentials are always the same size, even when ion gradients vary in size.




28. Which of the following statements about the phases of a neuronal action potential is true?A.

During the after-hyperpolarization phase, the permeability of the membrane to sodium ions isgreater than its permeability to potassium ions.

B.

During the after-hyperpolarization phase, the permeability of the membrane to potassium ions isgreater than its permeability at rest.

C.

During the repolarizing phase, the permeability of the membrane to sodium ions is greater than itspermeability to potassium ions.

D. Potassium channels inactivate during the depolarization phase.

E. Repolarizing to negative membrane potentials causes the sodium channels to inactivate. Blooms: Level 1. Remember



29. Which of the following statements about the refractory period of a membrane is true?A.

The absolute refractory period refers to the period of time during which another action potentialcannot be initiated in that part of the membrane that is undergoing an action potential, no matter howgreat the strength of the stimulus.

B.

The relative refractory period refers to the period of time during which another action potential canbe initiated in that part of the membrane that has just undergone an action potential if a stronger than

normal stimulus is applied.C.

The refractory period prevents the action potential from spreading back over the part of themembrane that just underwent an action potential.

D.

The refractory period places an upper limit on the frequency with which a nerve cell can conductaction potentials.

E. All of the above choices are correct.






30. The relative refractory period of an axon coincides with the period ofA. activation and inactivation of voltage-dependent Na+ channels.B. Na+ permeability that is greater than that during the depolarization phase.C. increased K+ flux into the cell.D. increased K+ permeability of the cell.

E. Increased Na+ flux through K+ channels.




31. Neuronal axons typically have abundantA. voltage-gated channels for Na+ that open in response to depolarization.

B. voltage-gated channels for K+ that open in response to hyperpolarization.C. receptor-mediated channels for Na+.D. receptor-mediated channels for K+.E. voltage-gated channels for Ca2+.




32. Which of the following statements regarding action potentials generated in a neuronal membrane isnot true?A. Action potentials travel decrementally down the membrane.

B. An action potential generates a new action potential in an adjacent area of membrane.C. An action potential generates a local current that depolarizes adjacent membrane to threshold

potential.D. Action potentials are usually initiated at the initial segment of a neuron.E.

An action potential generated by a threshold stimulus is the same size as one generated by a supra-threshold stimulus.




33. Which of the following statements concerning the properties of action potentials is true?A. The rate of propagation of an action potential down an axon is independent of stimulus strength.

B. Action potentials can undergo summation.C. A supra-threshold stimulus can stimulate an action potential during the absolute refractory period.D. Action potentials generally propagate from the axon terminal toward the initial segment.E. Increasing the size of a stimulus will increase the amplitude of an action potential.




34. How is the strength of a stimulus encoded by neurons?A. by the size of action potentialsB. by the frequency of action potentials

C. by the duration of action potentialsD. by whether the action potential peak is positive or negative






35. Which of the following statements concerning the rate of action potential propagation is true?A. It is faster in small-diameter axons than in large-diameter axons.B. It is faster for a strong stimulus than for a weak one.C. It is faster in myelinated axons than in nonmyelinated axons.

D. It is faster in the dendrites than in the axon.E. It occurs at the same rate in all axons, regardless of their diameter.




36. An action potential does not re-stimulate the adjacent membrane that was previously depolarizedbecauseA. stimulation is inhibited by the myelin sheath.B. it is impossible for an action potential to be propagated along an axon toward the nerve cell body.C. the resting membrane potential of the axon is too positive.D. the resting membrane potential of the axon is too negative.E. that area of the membrane is in the absolutely refractory period.


Section: 06.07


37. The regions of axon membrane that lie between regions of myelin are theA. islets of Langerhans.B. nodes of Ranvier.

C. synaptic membranes.D. glial cells.E. dens of iniquities.



Section: 06.01 Section: 06.07


38. Which is FALSE about interneurons?A. They receive synaptic input from other other neurons in the CNS.B. They sum excitatory and inhibitory synaptic inputs.C. They deliver synaptic input on other neurons.D.

They make synapses on effector organs in the PNS.

E. They can transmit information between afferent neurons and efferent neurons.



Section: 06.02


39. Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in responseto the arrival of an action potential in the axon terminal.A. K+ B. Na+ C. Ca2+

D. ATPE. Cl-



Section: 06.09




40. The main role of calcium ions at chemical synapses is toA. depolarize the axon terminal of the presynaptic cell.B.

bind to neurotransmitter receptors on the postsynaptic cell.

C. cause fusion of synaptic vesicles with the plasma membrane of the axon terminal.

D. interfere with IPSPs in the postsynaptic cell.E. diffuse across the synaptic space and enter the postsynaptic cell.




Section: 06.09


41. At an excitatory chemical synapse between two neurons,A. there is increased permeability of the postsynaptic cell to both Na+ and K+.

B. a small hyperpolarization of the postsynaptic membrane occurs when the synapse is activated.C. an action potential in the presynaptic neuron always causes an action potential in the postsynaptic

neuron.D. excitation occurs because K+ enters the postsynaptic cell.E. action potentials spread through gap junctions between cells.



Section: 06.10


42. An inhibitory postsynaptic potential:A.

is produced by simultaneous increases in permeability to both Na+ and K+.

B. occurs when a ligand-gated ion channel increases its permeability to K+.

C. is a small depolarization in a postsynaptic cell.D. can be summed with other IPSPs to trigger an action potential in the postsynaptic cell.E. is produced by an increase in permeability to only Na+.




Section: 06.10


43. Which of the following statements about EPSPs is false?A. They are produced by the opening of chemically-gated sodium channels.B. They transmit signals over relatively short distances.C.

They depolarize postsynaptic cell membranes.

D. They are able to summate.E. They are always the same amplitude.




Section: 06.10




44. An EPSP:A. is a direct result of the opening of ligand-gated channels permeable to both Na+ and K+ ions.

B. is a direct result of the opening of voltage-gated channels permeable to both Na+ and K+ ions.C. stabilizes the membrane to remain at its resting potential.D. opens voltage-gated Ca2+ channels in the presynaptic membrane.E. occurs when voltage-gated Cl- channels open in a postsynaptic cell membrane.



Section: 06.10


45. Which best describes temporal summation?A. A synapse is stimulated a second time before the effect of a first stimulus at the synapse has

terminated.B. It only refers to addition of EPSPs.C. Two synapses on different regions of a cell are stimulated at the same time.D. It always brings a postsynaptic cell to threshold.E. The size of an EPSP depends on the size of the stimulus.



Section: 06.11


46.

A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. Stimulation ofneuron X causes the postsynaptic neuron to depolarize by 0.5 mV. When X and Y are stimulatedsimultaneously, the postsynaptic neuron depolarizes by 1 mV. When X and Z are stimulatedsimultaneously, however, there is no change in the membrane potential of the postsynaptic neuron.What is most likely true about presynaptic neurons Y and Z?

A. They are both excitatory.

B. They are both inhibitory.C. Y is excitatory and Z is inhibitory.

D. Z is excitatory and Y is inhibitory.


Section: 06.11


47.

A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. When X and Y arestimulated simultaneously and repeatedly, the postsynaptic neuron reaches threshold and undergoes

an action potential. When X and Z are stimulated simultaneously, however, there is no change inthe membrane potential of the postsynaptic neuron. The simultaneous stimulation of X and Y is anexample of

A. temporal summation.B. presynaptic inhibition.C. spatial summation.

D. neuronal divergence.E. presynaptic facilitation.



Section: 06.11




48. Which is TRUE about the initial segment of an axon?A. Its threshold potential is more positive than that of the cell body and dendrites.B. Its threshold potential is more negative than that of the cell body and dendrites.

C.

Synapses far from the initial segment are more effective in influencing whether an action potentialwill be generated in the axon than are synapses close to the initial segment.

D. It is the region where neurotransmitter vesicles are docked and ready to be released by exocytosis.E. It can only conduct graded potentials because it lacks voltage-gated Na+ channels.



Section: 06.11


49. A presynaptic synapse:A. is a synapse between an axon terminal and a dendrite that can be either excitatory or inhibitory.B.

is a synapse between an axon terminal and another axon's terminal that can be either excitatory orinhibitory.

C. is any synapse onto a cell body, and they can be either stimulatory or inhibitory.D. is a synapse between an axon terminal and a dendrite of the same cell, which is always inhibitory.

E. is a synapse between an axon terminal and another axon terminal that is always inhibitory.



Section: 06.12


50. Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuronZ. Which will occur when action potentials are stimulated in neuron X?A. Neuron Y will be inhibited from reaching the threshold to fire an action potential.B. The release of neurotransmitter by neuron Y will be inhibited.

C. The synapse between neurons Y and Z will be changed from an excitatory synapse to an inhibitoryone.

D. Neurons Y and Z will both be more likely to reach threshold and fire an action potential.E. Neurons Y and Z will both be less likely to reach threshold and fire an action potential.



Section: 06.12


51. Which of the following is not known to be an important neurotransmitter in the CNS?A. DopamineB. AcetylcholineC. Morphine

D. Glutamate

E. Substance P



Section: 06.13


52. Which of the following statements about acetylcholine is correct?A. Acetylcholine binds to nicotinic and muscarinic receptors.

B. Acetylcholine binds to adrenergic receptors.C. Acetylcholine synthesis is catalyzed by acetylcholinesteraseD. Acetylcholine is the neurotransmitter released by most sympathetic postganglionic neurons.E.

Acetylcholine is generally transported back into presynaptic nerve terminals without being

enzymatically degraded.



Section: 06.13




53. Which of the following statements regarding neurotransmitters is TRUE?A. Acetylcholine is broken down by enzymes present on postsynaptic cell membranes.

B. Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cellmembrane.

C. Catecholamines are the most abundant neurotransmitters in the central nervous system.D. Opiate drugs, such as morphine, are antagonists of a class of neurotransmitters called endorphins.E. Gamma-aminobutyric acid (GABA) is a major excitatory transmitter in the central nervous system.



Section: 06.13


54. Acetylcholine is the main neurotransmitter released by:A. preganglionic sympathetic neurons and cells of the adrenal medulla.B. cells of the adrenal medulla and postganglionic parasympathetic neurons.C. motor neurons and postganglionic sympathetic neurons.D. preganglionic sympathetic neurons and postganglionic sympathetic neurons.E. preganglionic sympathetic neurons and motor neurons.




Section: 06.13


55. Which of the following statements about norepinephrine is FALSE?A. Norepinephrine is a neurotransmitter.B. Norepinephrine binds to adrenergic receptors.C. Norepinephrine is a catecholamine.D. Dopamine is a precursor to norepinephrine.E. Epinephrine is a precursor to norepinephrine.




56. Which of the following enzymes is important for the metabolism of catecholamines?A. Tyrosine hydroxylase

B. AcetylcholinesteraseC. Superoxide dismutaseD. HydrocortinaseE. Adenyl cyclase


Section: 06.13


57. Nicotine is:A. a cholinergic antagonist.B. a beta-adrenergic agonist.C. a cholinergic agonist.

D. an alpha-adrenergic antagonist.E. a neurotransmitter.


Section: 06.13




58. Serotonin:A. acts as a neuromodulator.

B. is a catecholamine neurotransmitter.C. is a neuropeptide.D. has an inhibitory effect on pathways that are involved in the control of muscles.E. has an excitatory effect on pathways that mediate sensations.


Section: 06.13


59. Alzheimer's disease is thought to involve primarily:A. loss of neurons that secrete or respond to catecholamines.B. loss of adrenergic neurons.C. loss of cholinergic neurons.

D. loss of neurons that secrete or respond to dopamine.E. tumors that produce excess serotonin.



Section: 06.13


60. Which is one of the major inhibitory neurotransmittors in the CNS?A. GlutamateB. DopamineC. NorepinephrineD. Gamma-aminobutyric acid (GABA)

E. Beta-endorphin



Section: 06.13


61. Which is one of the most abundant excitatory neurotransmittors in the CNS?A. Glutamate

B. DopamineC. NorepinephrineD. Gamma-aminobutyric acid (GABA)E. Endorphin



Section: 06.13


62. The central nervous system includes the:

A. afferent nerves and spinal cord.B. efferent nerves and spinal cord.C. autonomic nervous system and the brain.D. brain stem and the autonomic nervous system.E. brain and spinal cord.



Section: 06.15




63. The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletalmuscle is called the:A. afferent nervous system.B. sympathetic nervous system.C. parasympathetic nervous system.D. somatic motor nervous system.

E. autonomic nervous system.




64. The region of the brain that is the most important control area for homeostatic regulation of theinternal environment is:A. the thalamus.B. the hippocampus.C. the cerebrum.D. the cerebellum.E. the hypothalamus.



Section: 06.15


65. Which of the following kinds of neurons is not generally cholinergic?A. somatic motor neuronsB. postganglionic sympathetic neurons

C. postganglionic parasympathetic neuronsD. preganglionic sympathetic neuronsE. preganglionic parasympathetic neurons




66. Which of the following does NOT result from the binding of nicotine with nicotinic acetylcholinereceptors?A. a mild form of skeletal muscle paralysis that creates a more relaxed state

B. signal transmission at neuromuscular junctionsC. generation of excitatory signals within autonomic gangliaD.

the release of norepinephrine, dopamine, and epinephrine

E.

facilitation of the release of multiple neurotransmitters within the brain, including the "reward

pathway" involving dopamine


Section: 06.13


67. Drug X interferes with the action of norepinephrine at synapses. Which of the following mechanismswould not explain the effects of X?A. X inhibits synthesis of norepinephrine at the axon terminal.B. X inhibits norepinephrine release from the terminal.C. X blocks reuptake of norepinephrine by the terminal.

D. X is an adrenergic receptor antagonist.

E. X stimulates the catabolism of norepinephrine.


Section: 06.13




68. Synthesis of neuropeptides differs from that of other neurotransmitters because it:A. takes place in the axon terminals of neurons.B. takes place in the cell bodies of neurons.

C. takes place on ribosomes in the postsynaptic cell's membrane.D. uses amino acids as precursor molecules.E. only takes place at synapses outside the central nervous system.


Section: 06.13


69. Which best describes the reticular formation of the brain?A. It is mainly involved in motor coordination and balance.B. It is the master endocrine gland of the brain.C. It is primarily responsible for visual perception.D.

It integrates information from all regions of the CNS, and incorporates the mechanisms thatregulate sleep and wakefulness.

E. It is the primary synaptic relay station for sensory information entering the CNS.



Section: 06.15


70. The cerebellum:A. is important for coordinating body movement.

B. is the gray matter covering the entire surface of the brain.C. is the same thing as the brain stem.D. is in the anterior portion of the brain, just above the eyes.E. is one of the basal nuclei that is found deep inside the cerebrum.



Section: 06.15


71.

The ________________ is best described as "an interconnected group of brain structures includingparts of the frontal lobe-cortex, temporal lobe, thalamus, and hypothalamus, that is associated withlearning, emotional experience, and behavior?"

A. diencephalonB. cerebrumC. limbic system

D. reticular formation

E. cerebellum



Section: 06.15


72. Which is a FALSE statement about the cerebrospinal fluid?A. It has the same composition as blood plasma.

B. It acts as a cushion for the brain and spinal cord.C. It is secreted by cells lining the ventricles of the brain.D. It circulates within and between brain ventricles and surrounds the spinal cord.E. It is in diffusion equilibrium with the extracellular fluid of the central nervous system.



Section: 06.19




73.

Which of the following is NOT characteristic of the sympathetic division of the ANS?

A. Preganglionic neurons tend to be long, with the ganglion located in or near the effector targettissue(s).

B. Preganglionic neurons are short and synapse in ganglia located near the spinal cord.C. Preganglionic neurons release acetylcholine at synapses with postganglionic neurons.

D. Postganglionic neurons release norepinephrine at their neuroeffector junctions.E. Postganglionic neuron cell bodies are located in the collateral chain ganglia (sympathetic trunk).





74. Postganglionic neuron cell bodies of the autonomic nervous system have which category ofneurotransmitter receptor?A. Adrenergic receptorB. Serotonin receptorsC. Muscarinic acetylcholine receptors

D. Nicotinic acetylcholine receptorsE. Dopamine receptors




75. A myelinated axon is shielded from direct contact with the extracellular fluid all along its length.FALSE




Section: 06.01


76. The lipid portion of a cell's plasma membrane constitutes a barrier to current.TRUE



Section: 06.05


77.FALSE

Ions other than Na+, K+, and Cl- play no role in generating the resting membrane potential of a cell.




78. The maintenance of a resting potential in a neuron depends indirectly upon the functioning of the Na+,K+-ATPase pumps in the membrane.TRUE



Section: 06.06




79. A graded potential in a membrane results in an electric current along an adjacent area of membraneand this current diminishes with distance from the site of the initial potential change.TRUE





80. During a hyperpolarizing graded potential, positively charged ions flow away from the site of the

initial hyperpolarization on the outside of membrane and toward this site on the inside.TRUE





81. Because so many Na ions move into a cell during an action potential and so many K ions move out,no further action potentials can be generated in a given membrane until the Na, K-ATPase pumps canrestore the concentration gradient.FALSE





82. The Na+ and K+ channels that open during an action potential are voltage regulated, both opening inresponse to depolarization of the membrane.TRUE





83. SNARE receptor protein complexes in presynaptic neurons function as inhibitors of calcium transport

to dampen or reduce the amount of neurotransmitter vesicles which participate in exocytosis.FALSE




Section: 06.09


84. The action potential elicited by a supra-threshold stimulus is larger than one elicited by a thresholdstimulus.FALSE




Section: 06.07


85. The relative refractory period of an excitable membrane refers to the period of time during which nostimulus, however strong, will elicit a second action potential in the membrane.FALSE





86. The absolute refractory period of an excitable membrane roughly corresponds to the period whensodium channels are opening and inactivated.

TRUE





87. Because all parts of a neuronal cell body have the same threshold, no one synapse on the cell is moreimportant than any other.FALSE


Chapter - Chapter 06 #87 Learning Outcome: 06.07 Learning Outcome: 06.11

Section: 06.07 Section: 06.11


88. The frequency of action potentials in a postsynaptic cell is directly related to the degree ofdepolarization of the postsynaptic cell.TRUE




89. Catecholamines are the most abundant neurotransmitters in the CNS.FALSE





90. Opioid drugs, such as morphine, are agonists of a class of neurotransmitters called endorphins.TRUE




Section: 06.13


91. The most common neurotransmitters for neuroeffector communication are dopamine andacetylcholine.FALSE




Section: 06.14


92. Dorsal root ganglia contain the cell bodies of efferent neurons.FALSE





93. Spinal nerves are composed of the axons of both afferent and efferent neurons.

TRUE




94. Although nerve cells in each cerebral hemisphere make connections with other cells in the samehemisphere, there is no crossover of information between the two hemispheres.FALSE




Section: 06.15




95. The cerebrum consists only of gray matter.FALSE




Section: 06.15


96. The basal ganglia are important subcortical nuclei in the cerebrum.TRUE


Section: 06.15


97. The thalamus is the single most important control area for regulating the homeostasis of the internalenvironment.FALSE



Section: 06.15


98. The efferent division of the peripheral nervous system consists of the somatic nervous system and theautonomic nervous system.TRUE




99. Preganglionic fibers of the parasympathetic division of the autonomic nervous system leave the CNSat the level of the brainstem and sacral portions of the spinal cord.TRUE





100. Most of the parasympathetic ganglia lie in chains along the spinal cord called sympathetic trunks.FALSE





101. Responses made possible by motor signals transmitted by the parasympathetic nervous system tend tobe displayed throughout the body simultaneously because there is much divergence of nerve pathways

and close anatomical association between presynaptic neurons and their ganglia as well as accessoryactivity with the adrenal glands.FALSE







102.TRUE

The sympathetic division of the autonomic nervous system is arranged so that it acts largely as aunit, whereas the components of the parasympathetic division generally act as discreet, independentcomponents.





103. "Dual innervation of effectors" refers to the innervation of the same effector organs by somatic andautonomic nerves.FALSE







6 Summary

Category # of Questions

Blooms: Level 1. Remember 78

Blooms: Level 2. Understand 25

Chapter - Chapter 06 103

Learning Outcome: 06.01 5

















Section: 06.01 5

Section: 06.02 3

Section: 06.03 1

Section: 06.05 3

Section: 06.06 13

Section: 06.07 28

Section: 06.09 3

Section: 06.10 4

Section: 06.11 5

Section: 06.12 2

Section: 06.13 16

Section: 06.14 1

Section: 06.15 10

Section: 06.16 2

Section: 06.17 2

Section: 06.18 9

Section: 06.19 1

Topic: Nervous System 103

Documents

human physic human physic bio chem test ready stuff of test