Chapter 10 Multiple Choice

The cytoplasmic extensions that, together with the cell body, provide the main receptive surfaces for neurons are A. neurofibrils. B. chromatophilic substance (Nissl bodies). C. axons. D. dendrites. E. synapses.

The two types of cells of the nervous system are A. axons and dendrites. B. neurons and neuroglia. C. motor neurons and sensory neurons. D. Schwann cells and microglia. E. neurons and muscle cells.

The space between neurons is a A. dendrite. B. gap junction. C. bleb. D. neurotransmitter. E. synapse.

The nervous system A. detects changes in the internal or external environment. B. controls the movement of muscles. C. regulates secretion. D. integrates information from several sources and uses it to respond appropriately. E. all of the above

Neurons that convey impulses from the CNS to muscles or glands are A. effectors. B. receptors. C. oligodendrocytes. D. neurotransmitters. E. none of the above.

Sensory receptors A. monitor light B. monitor sound. C. are part of the PNS. D. detect changes in and outside the body. E. all of the above.

Three general functions of the nervous system are A. sensory, motor, and predictive. B. integrative, motor, and sensory. C. predictive, manipulative, and integrative. D. reflexive, sensory, and predictive. E. seeing, feeling, and touching.

Masses of myelinated nerve fibers appear A. white. B. gray. C. brown. D. transparent. E. wet.

A neuron may have A. one axon and many dendrites. B. one dendrite and many axons. C. no dendrites. D. no axons. E. more than one cell body.

_________ support the axon from within. A. Dendrites. B. Nodes of Ranvier. C. Neurofibrils. D. Collaterals. E. Myofilaments

Every neuron has A. many axons. B. a cell body. C. myelin. D. a neurilemma. E. a cell wall.

Which of the following is unique to neurons? A. Golgi apparatus B. Chromatophilic substance C. Mitochondria D. Lysosomes E. Ribosomes

Myelin A. is released from a neuron and travels to another neuron. B. comprises much of the cell membrane of Schwann cells. C. is a type of neuron. D. is a form of chromatophilic substance that fills Schwann cells. E. is produced in response to bacterial infection.

A myelinated nerve fiber is ______, whereas an unmyelinated nerve fiber is ______. A. gray, and composing the gray matter of the brain and spinal cord; white, and composing the white matter of the brain and spinal cord B. white, and composing the gray matter of the brain and spinal cord; gray, and composing the white matter of the brain and spinal cord C. white, and composing the white matter of the brain and spinal cord; gray, and composing the gray matter of the brain and spinal cord D. white, and composing the gray matter of the brain and spinal cord; red, and composing the white matter of the brain and spinal cord E. none of the above

Myelin is rich in ___________. A. proteins B. carbohydrates C. lipids D. salts E. bacteria

Which of the following is(are) a type of neuroglia? A. Astrocyte B. Oligodendrocyte C. Ependymal cell D. Schwann cell E. all of the above

Which cells produce myelin in the brain and spinal cord? A. Schwann cells B. Astrocytes C. Microglia D. Oligodendrocytes E. Motor neurons

A reason that the CNS and PNS differ in their ability to regenerate after injury is that A. axons of the CNS lack myelin. B. axons of the CNS lack neurilemmae. C. peripheral nerves lack Schwann cells. D. peripheral nerves lack endoneurium. E. CNS axons have direct access to the brain.

Most of the neurons in the brain and spinal cord are A. bipolar. B. unipolar C. multipolar. D. nonpolar. E. isopolar.

In order for a severed peripheral nerve to regenerate and recover its original function, nerve fibers must sprout and enter tubes formed by A. basement membranes and connective tissues. B. former axons. C. myelin. D. nodes of Ranvier. E. microtubules.

Which of the following cells is only found in the PNS? A. Oligodendrocyte B. Astrocyte C. Microglial cell D. Schwann cell E. Neuron

Dendrites on unipolar neurons are part of A. sensory neurons. B. motor neurons. C. interneurons. D. efferent neurons. E. affective neurons.

Clusters of neuron cell bodies are called _____. A. soma B. axons C. ganglia D. nuclei E. neuromas

Which of the following neuroglia is not part of the CNS? A. Ependymal cells B. Astrocytes C. Interneurons D. Microglia E. Satellite cells

Synaptic knobs are at the ends of A. axons. B. dendrites. C. cell bodies. D. neuroglia. E. mitochondria.

Presynaptic neurons release neurotransmitters by ______________. A. endocytosis. B. exocytosis. C. transcytosis. D. active transport. E. diffusion.

When an action potential passes over the surface of a synaptic knob, the contents of the vesicles are released in response to the presence of A. calcium ions. B. sodium ions. C. neurotransmitters. D. neuropeptides. E. morphine.

If a neuron receives a series of stimuli whose effect is excitatory but subthreshold, the neuron is more excitable to incoming stimulation than before and is said to be A. graded. B. amplified. C. facilitated. D. converged. E. highlighted.

Transmitting a nerve impulse from one neuron to another involves a A. nerve impulse stimulating presynaptic dendrites to release a neurotransmitter into a synaptic cleft. B. nerve impulse stimulating a presynaptic axon to release a neurotransmitter into a synaptic cleft. C. neurotransmitter traveling from presynaptic dendrites across a synapse to postsynaptic axons or a cell body. D. neurotransmitter traveling from postsynaptic axons across a synapse to presynaptic dendrites or a cell body. E. none of the above.

Action potentials are related to nerve impulses in that A. many nerve impulses are required to cause one action potential. B. active transport of Na+ and K+ are required for a nerve impulse but not for an action potential. C. nerve impulses are stronger responses than are action potentials. D. propagation of action potentials along a fiber constitutes a nerve impulse. E. an action potential consists of several nerve impulses.

A stimulus great enough to change the membrane potential and propagate an action potential is said to have reached _________. A. recruitment B. nirvana C. summation D. tetanus E. threshold

When a nerve fiber is polarized, the concentration of A. Na+ and K+ is higher on the inside of the membrane. B. Na+ and K+ is higher on the outside of the membrane. C. Na+ is higher on the inside of the membrane and K+ is higher on the outside. D. Na+ is higher on the outside of the membrane and K+ is higher on the inside. E. Ca2+ is equal on both sides of the membrane.

Saltatory conduction A. occurs only if the myelin sheath is continuous. B. occurs only if nodes of Ranvier are lacking. C. is faster than conduction on an unmyelinated fiber. D. is slower than conduction on an unmyelinated fiber. E. occurs only if a person is near an ocean.

The most rapid nerve impulses are conducted on fibers that are A. thick and myelinated. B. thick and unmyelinated. C. thin and myelinated. D. thin and unmyelinated. E. of medium thickness with spots of myelin.

Which of the following ions cross cell membranes most readily? A. Potassium B. Sodium C. Calcium D. Carbonate E. Magnesium

If a resting potential becomes more negative, the membrane is A. depolarizing. B. hyperpolarizing. C. repolarizing. D. summating. E. hyperexcitable.

What is the correct sequence of events that follows a threshold potential? A. 3, 2, 4, 1 B. 2, 1, 4, 3 C. 1, 2, 4, 3 D. 4, 1, 3, 2 E. 1, 2, 3, 4

A nerve cell membrane may become depolarized as a result of A. unequal distribution of ions on each side of the membrane. B. some ion channels being opened while others are closed. C. the relative ease with which K+ diffuses through membranes. D. totally preventing Na+ from passing through the membrane. E. none of the above.

Which of the following molecules is responsible for "runner's high," a good feeling that accompanies long-distance running? A. Beta endorphin B. Acetylcholine C. Epinephrine D. Dopamine E. Alcohol

An excitatory postsynaptic potential lasts for about A. 15 minutes. B. 15 seconds. C. 15 milliseconds. D. 15 microseconds. E. 15 nanoseconds.

Each neuron in the CNS receives input from A. only one synaptic knob. B. one synaptic knob at each end. C. synaptic knobs only when a person is awake. D. about 10 dendrites. E. thousands of axons.

An action potential is triggered if A. EPSPs overpower IPSPs. B. IPSPs overpower EPSPs. C. chloride channels open. D. the membrane hyperpolarizes. E. all of the above.

The neurotransmitter that controls skeletal muscle contraction is A. beta endorphin. B. nitric oxide. C. acetylcholine. D. GABA E. nitrous oxide.

Viagra is a drug used to treat erectile dysfunction by dilating arteries in the penis. The neurotransmitter that Viagra affects is A. acetylcholine. B. nitric oxide. C. serotonin. D. histamine. E. rigidoxine.

Neurotransmitters that are modified amino acids are A. dopamine, serotonin, epinephrine, and norepinephrine. B. enkephalins, endorphins, and substance P. C. aspartic acid, glutamic acid, glycine, and GABA. D. potassium, sodium, and calcium ions E. methyl, ethyl, and ketone bodies

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are most likely used to treat A. multiple sclerosis. B. Tay-Sachs disease. C. clinical depression. D. schizophrenia. E. erectile dysfunction.

In reuptake A. an action potential reverses direction. B. a neuropeptide breaks down into amino acids, which act as neurotransmitters. C. a neurotransmitter that has already been released into the synaptic cleft is taken back into the synaptic knob of the presynaptic neuron or into nearby neuroglia or neurons. D. an enzyme breaks down a neurotransmitter and then another enzyme builds it back up. E. parts of neurotransmitters floating in the synapse come together to restore levels.

During an action potential, calcium ions cause A. potassium channels to open. B. potassium channels to close. C. sodium channels to open. D. potassium and sodium channels to relocate in the membrane. E. sodium channels to close.

Drugs that inhibit the enzyme monoamine oxidase A. allow increased activity of norepinephrine. B. decompose norepinephrine. C. decrease the activity of serotonin. D. decompose serotonin. E. are associated with heart disease.

The types of neurons that are organized into neuronal pools are A. interneurons. B. intraneurons. C. mixed neurons. D. astrocytes. E. Schwann cells.

Convergence refers to A. dendrites from neurons in different parts of the nervous system contacting the same neuron. B. axons from neurons in different parts of the nervous system contacting the same neuron. C. dendrites from the same neuron touching each other. D. a neuroglial cell that contacts many neurons. E. dendrites contacting the axon of their own cell.

Diverging axons amplify an impulse by A. contacting many neurons. B. returning the impulse to the neuron of origin. C. splitting into multiple axons. D. stimulating themselves. E. none of the above.

Neural stem cells can be harvested from autopsies and stored, alive, in banks, whereas neurons cannot, because A. the people will them to science. B. neural stem cells have lower oxygen and energy requirements than neurons. C. neural stem cells have higher oxygen and energy requirements than neurons. D. neural stem cells have more globular shapes than neurons. E. none of the above.

Migraine results from A. release of calcitonin gene-related peptide from the trigeminal nerves at the base of the brain, in response to a spreading wave of excitation followed by lack of response from the cortex. B. not eating enough chocolate, which causes a spreading effect in the cortex. C. a neurotransmitter deficiency. D. release of an abnormal form of beta endorphin from the trigeminal nerves at the base of the brain, in response to cortical stimulation. E. inappropriate release of endorphins.

Multiple sclerosis is caused by an abnormal response of the A. circulatory system. B. muscular system. C. immune system. D. neurotransmitter system. E. excretory system.

An immune response that triggers inflammation of the spinal cord and brain, leaving scars is A. muscular dystrophy. B. multiple sclerosis. C. Alzheimer disease. D. amyotrophic lateral sclerosis. E. chronic fatigue syndrome.

Drugs that decrease membrane permeability to sodium A. are used as local anesthetics. B. prevent nerve impulses from passing through the affected body part. C. lessen pain. D. are short-acting. E. all of the above.

Opiate drugs derived from poppies relieve pain in humans because the human nervous system has A. neurotransmitters. B. receptors for endogenous opiates. C. myelin. D. endogenous opiates. E. chlorophyll.

Marjorie takes an anti-anxiety drug so that she can sleep better and remain calm enough to study effectively. She begins by taking 25 milligrams every evening, but within a month, this dose is no longer helping, so she takes two pills. After another month, this dosage is no longer effective. This is happening because A. her immune system is rejecting the drug. B. she has developed tolerance, which means that her liver can no longer metabolize the drug, so it remains active for too long. C. the number of receptors to which the drug binds on neurons has declined. D. the number of receptors to which the drug binds on neurons has increased. E. her roommate substituted Tylenol pills.

The neurotransmitter most likely produced when a person uses a drug that creates a sense of well-being is A. glutamic acid. B. dopamine. C. enkephalin. D. substance Q. E. acetylcholine.

A drug that functions as an agonist A. activates a receptor, helping a neurotransmitter bind or triggering an action potential in some other way. B. causes great pain if taken in too high a dose. C. blocks a receptor so that the neurotransmitter cannot bind. D. relieves pain. E. adds receptors to cells.