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A&P Ch. 10 PracQuiz
Practice Quiz
Question | Answer |
---|---|
The brain and spinal cord comprise the central nervous system. Group of answer choices True False | T |
Myelin is composed largely of carbohydrates. Group of answer choices True False | F |
The resting cell membrane is more permeable to which ion? Group of answer choices Potassium Sodium Calcium Magnesium | Potassium |
What are the three general functions of the nervous system? Group of answer choices Sensory, motor, and predictive Integrative, motor, and sensory Predictive, manipulative, and integrative Reflexive, sensory, and predictive | Integrative, motor, and sensory |
When is an action potential triggered? Group of answer choices When EPSPs exceeds IPSPs When IPSPs exceeds EPSPs When chloride channels open When potassium channels open | When EPSPs exceeds IPSPs |
The space between neurons in a pathway is called the neuronal space. Group of answer choices True False | F |
What is the correct sequence of events that occurs along an axon after the membrane reaches threshold? The membrane depolarizes. Sodium channels open and sodium ions diffuse inward. The membrane repolarizes. Potassium channels open and potassium ions diffuse outward. Group of answer choices 3, 2, 4, 1 2, 1, 4, 3 1, 2, 4, 3 4, 1, 3, 2 | 2, 1, 4, 3 |
Enkephalins are neuropeptides. Group of answer choices True False | T |
Masses of myelinated nerve fibers appear__________. Group of answer choices white gray brown transparent | white |
What is a function of the nervous system? Group of answer choices Provides a support system for the body Controls the movement of muscles Contracts and generates a force to cause bodily motion Provides nutrients and nourishment for surrounding cells | controls the movement of muscles |
How does a neuron cell membrane become depolarized? Group of answer choices Ca+2 channels open and Ca+2 ions diffuse out of the cell. Na+ channels open and Na+ ions diffuse into the cell. K+ channels open and K+ ions diffuse into the cell. Na+ channels close and Na+ ions can't diffuse into the cell. | Na+ channels open and Na+ ions diffuse into the cell. |
What is myelin? Group of answer choices A substance released from a neuron that travels to another neuron. Layers of lipids and proteins that wrap around an axon. A substance produced in response to bacterial infection. A form of chromatophilic substance that fills Schwann cells. | Layers of lipids and proteins that wrap around an axon. |
What is the function of sensory receptors? Group of answer choices To send signals from the brain to muscles To work with muscles to generate motion To detect changes in and outside the body To act as a pathway between the ascending and descending tracts within the spinal cord | To detect changes in and outside the body. |
Every neuron has which of the following components? Group of answer choices Many axons A cell body Myelin A neurilemma | A cell body |
If a resting potential becomes more negative, the membrane is said to be__________. Group of answer choices depolarized hyperpolarized repolarized summated | Hyperpolarized |
When an action potential passes over the surface of a synaptic knob, the contents of the vesicles within the synaptic knob are released in response to the presence of__________. Group of answer choices calcium ions sodium ions neurotransmitters neuropeptides | calcium ions |
Presynaptic neurons release neurotransmitters by the process of__________. endocytosis exocytosis diffusion active transport | exocytosis |
Neuroglia are specialized to react to environmental change, and neurons support neuroglia. True False | F |
What are the two major cell types found in nervous tissue? Neurons and neuroglia Dendrites and axons Neurons and effectors Astrocytes and Schwann cells Neurons and nerves | Neurons and neuroglia |
Which cells produce myelin in the brain and spinal cord? Schwann cells Astrocytes Microglia Oligodendrocytes | Oligodendrocytes |
A neuron in the aorta detects oxygen content in the blood and relays this information to the brain. This neuron is an__________ fiber in the__________ nervous system. efferent; somatic efferent; autonomic afferent; autonomic afferent; somatic | afferent; autonomic |
A person is exposed to a drug that prevents vesicles from forming in neurons. Predict the effect this will have on nerve function. Voltage-gated potassium channels will be blocked, slowing depolarization and slowing nerve impulses. Neurons will be hyper-excitable. Neurotransmitters won’t be released into the synapse. Action potentials will not be carried along the axon. | Neurotransmitters won’t be released into the synapse. |
If a neuron's membrane potential measures +25mV, the neuron is__________. polarized hyperpolarized depolarized repolarized | depolarized |
Which neurotransmitters are modified amino acids? Dopamine, serotonin, and epinephrine Enkephalins, endorphins, and substance P Aspartic acid, glutamic acid, and glycine Acetylcholine, nitric oxide, and GABA | Dopamine, serotonin, and epinephrine |
A positive feedback loop occurs when the outcome of an event causes the event to continue occurring and amplifies its effects. Which of the following aspects of an action potential constitutes a positive feedback loop? | An initial flow of sodium ions into the neuron causes the opening of more voltage-gated sodium channels, rapidly causing more sodium to enter. |
What disorder involves an immune response that affects the myelin coating on axons throughout the spinal cord and brain, triggering inflammation and leaving scars? Muscular dystrophy Multiple sclerosis Alzheimer disease Cerebrovascular accident | Multiple sclerosis |
How many axons and/or dendrites can a neuron have? One axon and many dendrites One dendrite and many axons No dendrites and many axons No axons and many dendrites | One axon and many dendrites |
The most rapid conduction of an impulse along an axon occurs on a fiber that is__________. thick and myelinated thick and unmyelinated thin and myelinated thin and unmyelinated | thick and myelinated |
Which of the following neuroglia are not part of the CNS? Ependymal cells Astrocytes Satellite cells Microglia | Satellite cells |
If a neuron is stimulated causing changes in the membrane potential to the point where voltage-gated Na+ channels open and begin depolarizing the cell, the neuron is said to have reached__________. recruitment threshold summation tetanus | threshold |
A neuron receives a stimulation that causes Cl- channels to open, resulting in a hyperpolarization of the neuronal membrane. This is an example of what type of potential? Facilitated potential Resting potential Excitatory postsynaptic potential Inhibitory postsynaptic potential | Inhibitory postsynaptic potential |
What neurotransmitter is most likely released when a person uses a drug that creates a sense of well-being? Glutamic acid Dopamine Enkephalin Substance Q | Dopamine |
A test organism develops a genetic mutation that causes neurons to develop without synaptic knobs. How will this impact neuronal function? Signal transduction down the axon will be interrupted, so the signal will not “jump” the synapse and reach the postsynaptic neuron. The dendrites of the postsynaptic neurons will have no means to attach to presynaptic axons. No neurotransmitters will be stored or released into the synapse to signal the postsynaptic neuron. | No neurotransmitters will be stored or released into the synapse to signal the postsynaptic neuron. |
Which of the following cells is found only in the PNS? Oligodendrocyte Astrocyte Microglial cell Schwann cell | Schwann cell |
A neuron is exposed to a drug that completely blocks voltage-gated potassium channels, but has no effect on non-gated channels or the sodium-potassium pump. Which of the following describes the effect on action potential generation? Threshold will never be crossed, and therefore an action potential will never be generated. Repolarization will still occur, but at an inefficiently slow rate. Resting potential would not be maintained, as potassium could not leak out of the neuron. | Repolarization will still occur, but at an inefficiently slow rate. |
What is the effect of drugs that inhibit the enzyme monoamine Increased activity of norepinephrine Decomposition of norepinephrine Decreased activity of serotonin Decomposition of serotonin | Increased activity of norepinephrine |
What occurs during reuptake? An action potential reverses direction. A neuropeptide breaks down into amino acids, which act as neurotransmitters. A neurotransmitter that has already been released into the synaptic cleft is taken back into the presynaptic neuron. An enzyme breaks down a neurotransmitter and then another enzyme builds it back up. | A neurotransmitter that has already been released into the synaptic cleft is taken back into the presynaptic neuron. |
What cytoplasmic extensions, together with the cell body, provide the main receptive surfaces for neurons? Neurofibrils Chromatophilic substance (Nissl bodies) Axons Dendrites | Dendrites |
A myelinated nerve fiber is_________, whereas an unmyelinated nerve fiber is_________. gray; white white; black white; gray gray; black | white; gray |
During the absolute refractory period, a stimulus of high intensity may trigger a nerve impulse. True False | F |
Several nerve fibers converging onto one neuron amplifies impulses. True False | F |
Sensory receptors are part of the CNS. True False | F |
A physiologist testing signal transduction rates in two different nerve fibers notices that one fiber conducts signals much faster than the other. Which is the most likely difference between the two? The faster nerve fiber has more axons. The faster nerve fiber has more dendrites. The faster nerve fiber is myelinated and the slower one is not. The slower nerve fiber is myelinated and the faster one is not. | The faster nerve fiber is myelinated and the slower one is not. |
What feature is unique to neurons? Golgi apparatus Chromatophilic substance Mitochondrion Lysosome | Chromatophilic substance |
The oculomotor nerve is a cranial nerve containing nerve fibers that innervate eye muscles and control eye movement. These fibers are examples of__________. sensory neurons interneurons motor neurons unipolar neurons | motor neurons |
Astrocytes structurally support neurons and also provide important signals and nutrients to neurons. True False | T |
The somatic nervous system controls voluntary actions and the autonomic nervous system oversees involuntary actions. True False | T |
The neurotransmitter that controls skeletal muscle contraction is__________. norepinephrine nitric oxide acetylcholine GABA | acetylcholine |
Roughly how long does an excitatory postsynaptic potential last? 15 minutes 15 seconds 15 milliseconds 15 microseconds | 15 milliseconds |
Axon branches are called collaterals. True False | T |
Most of the neurons in the brain and spinal cord are__________. bipolar unipolar multipolar nonpolar | multipolar |
How are action potentials related to impulses conducted along the length of an axon? Many impulses are required to cause one action potential. Active transport of Na+ and K+ is required for impulse conduction but not for an action potential. Impulses are stronger responses than action potentials. Propagation of a series of action potentials along a nerve fiber constitutes an impulse. | Propagation of a series of action potentials along a nerve fiber constitutes an impulse. |
Clusters of neuron cell bodies in the PNS are called__________. neuromas axons ganglia nuclei | ganglia |
In Guillain-Barre syndrome, the immune system attacks and degrades the myelin sheath of PNS axons. Predict the effect this will have on nerve impulse and motor function. The brain cannot generate motor signals for the efferent pathway. The brain will slowly degrade and various brain functions will be lost, including motor functions. Lost insulation from myelin will cause neurons of the PNS to lose saltatory conduction, resulting in poor muscle function. | Lost insulation from myelin will cause neurons of the PNS to lose saltatory conduction, resulting in poor muscle function. |
Viagra is a drug used to treat erectile dysfunction by dilating arteries in the penis. To do so, Viagra affects the neurotransmitter__________. acetylcholine nitric oxide serotonin histamine | nitric oxide |
In order for a severed peripheral nerve to regenerate and recover its original function, nerve fibers must sprout and enter tubes formed by__________. connective tissue former axons myelin Schwann cells | Schwann cells |
Because the response of a nerve fiber is all-or-none, a greater intensity of stimulus does not produce a stronger impulse. True False | T |
Axon terminals from several different neurons synapse onto a single neuron. Some of these presynaptic neurons are sending excitatory signals, while others are sending inhibitory signals. Over the course of the effects of these signals, the postsynaptic membrane potential reaches around -90mV. What is the overall effect on the postsynaptic neuron? The postsynaptic neuron stays at its resting potential. The postsynaptic neuron is inhibited from generating action potentials. | The postsynaptic neuron is inhibited from generating action potentials. |
Destruction of astrocytes would decrease the rate at which action potentials are transmitted. True False | F |
Synaptic knobs are at the ends of__________. axons dendrites cell bodies neuroglia | axons |
A certain drug decreases the membrane permeability of nerve fibers to sodium. What would be a possible effect? An increase in the amount of nerve impulses through an affected area. An increase in pain A decrease in pain Increas sensitivity to pain | A decrease in pain |
What cytoplasmic structure supports the axon? Dendrites Nodes of Ranvier Neurofibrils Collaterals | Neurofibrils |
A nerve is a single neuron that transmits impulses. True False | F |
Organize the following list of nervous system elements by their classifications as CNS or PNS elements. oligodendrocytes thermoreceptors (nerves that sense temperature) interneurons satellite cells brain motor neurons | CNS: brain, oligodendrocytes, interneurons PNS: thermoreceptors, satellite cells, motor neurons |
Dendrites of unipolar neurons are parts of what type of neuron? Sensory neurons Motor neurons Interneurons Efferent neurons | Sensory neurons |
A neuron receives a series of stimuli that increases the membrane permeability of Na+, but not enough to cause membrane potential to surpass -55mV. This neuron is said to be__________ because it received a subthreshold stimuli. graded amplified facilitated refractory | facilitated |
Interneurons are specialized to carry impulses from receptor cells into the brain or spinal cord. True False | F |
What structural type of neuron has a single process that extends from the cell body? Unipolar neuron Bipolar neuron Multipolar neuron | Unipolar neuron |
A drug that increases the action of serotonin by keeping serotonin in the synapse longer is most likely used to treat what disorder? Multiple sclerosis Tay-Sachs disease Clinical depression Erectile dysfunction | Clinical depression |
When ten or more pre-synaptic neurons conduct impulses to five or fewer post-synaptic neurons, the conduction pattern is said to be__________. divergent emergent hyperpolarizing convergent | convergent |
Nodes of Ranvier lie between neurons. True False | F |
Saltatory conduction__________. occurs only if the myelin sheath is continuous occurs only if nodes of Ranvier are lacking is faster than conduction on an unmyelinated fiber is slower than conduction on an unmyelinated fiber | is faster than conduction on an unmyelinated fiber |
What is convergence? Dendrites from neurons in different parts of the nervous system contact the same neuron. Axons from neurons in different parts of the nervous system contact the same neuron. Dendrites from the same neuron touch each other. A neuroglial cell contacts many neurons. | Axons from neurons in different parts of the nervous system contact the same neuron. |
How do diverging axons amplify an impulse? By stimulating many neurons By returning the impulse to the neuron of origin By splitting into multiple axons By stimulating themselves | By stimulating many neurons |
A mixed nerve includes different neuroglial cells. True False | F |
Why do opiate drugs derived from poppies relieve pain in humans? The human nervous system has neurotransmitters. The human nervous system has receptors for endorphins. The human nervous system has myelin. The human nervous system has sodium and potassium membrane channels. | The human nervous system has receptors for endorphins. |
What is a reason that the axons in the CNS and PNS differ in their ability to regenerate after injury? Axons of the CNS lack myelin. Axons of the CNS lack a neurilemma. Axons of the PNS lack Schwann cells. Axons of the PNS lack an endoneurium. | Axons of the CNS lack a neurilemma. |
In convergence, two or more incoming fibers stimulate a single neuron, whereas in divergence, impulses leaving a single neuron stimulate several other neurons. True False | T |
How is an impulse transmitted from one neuron to another? An impulse stimulating a presynaptic axon causes the release of neurotransmitters into a synaptic cleft. A neurotransmitter traveling from presynaptic dendrites crosses the synapse to postsynaptic axons or a cell body. A neurotransmitter traveling from postsynaptic axons crosses the synapse to presynaptic dendrites or a cell body. | An impulse stimulating a presynaptic axon causes the release of neurotransmitters into a synaptic cleft. |
What types of neurons are organized into neuronal pools? Interneurons Intraneurons Schwann cells Astrocytes | Interneurons |
Myelin is rich in_________. nucleic acids carbohydrates lipids salts | lipids |
Each neuron in the CNS may receive input from which structure(s)? From a single axon From a single dendrite From ten dendrites From thousands of axons | From thousands of axons |