Neural Tissue Flashcards
Which of the following is not a function of the nervous system?
A) sense the internal and external environments
B) integrate sensory information
C) coordinate voluntary and involuntary activities
D) direct long-term functions, such as growth
E) control peripheral effectors
D
The \_\_\_\_\_\_\_\_ nervous system is composed of the brain and spinal cord. A) autonomic B) peripheral C) central D) efferent E) afferent
C
The \_\_\_\_\_\_\_\_ nervous system controls the skeletal muscles. A) sympathetic B) parasympathetic C) afferent D) somatic E) autonomic
D
The part of the peripheral nervous system that carries sensory information to the CNS is designated A) motor. B) afferent. C) efferent. D) autonomic. E) somatic.
B
The efferent division of the peripheral nervous system innervates: A) skeletal muscle cells B) smooth muscle cells C) heart muscle cells D) glandular cells E) All of the answers are correct.
E
Which of the following is not a recognized structural classification for neurons? A) anaxonic B) bipolar C) multipolar D) pseudopolar E) unipolar
D
The most abundant class of neuron in the central nervous system is A) anaxonic. B) bipolar. C) multipolar. D) pseudopolar. E) unipolar.
C
The axon is connected to the soma at the A) telodendria. B) synaptic terminal. C) collaterals. D) axon hillock. E) synapse.
D
Branches that may occur along an axon are called A) telodendria. B) synaptic terminals. C) collaterals. D) hillocks. E) synapses.
C
Axons terminate in a series of fine extensions known as A) telodendria. B) terminals. C) collaterals. D) dendrites. E) synapses.
A
The site of intercellular communication between a neuron and another cell is the A) telodendria. B) synaptic terminals. C) collateral. D) hillock. E) synapse.
E
Neurons that are rare, small, and lack features that distinguish dendrites from axons are called A) anaxonic. B) unipolar. C) bipolar. D) tripolar. E) multipolar.
A
Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called A) anaxonic. B) unipolar. C) bipolar. D) tripolar. E) multipolar.
B
Neurons that have one axon and one dendrite, with the soma in between, are called A) anaxonic. B) unipolar. C) bipolar. D) tripolar. E) multipolar.
C
Neurons that have several dendrites and a single axon are called A) anaxonic. B) unipolar. C) bipolar. D) tripolar. E) multipolar.
E
Sensory neurons of the PNS are A) unipolar. B) bipolar. C) anaxonic. D) multipolar. E) tripolar.
A
Which of the following activities or sensations is not monitored by interoceptors? A) sight B) taste C) activities of the digestive system D) cardiovascular activities E) urinary activities
A
\_\_\_\_\_\_\_\_ neurons are small and have no anatomical features that distinguish dendrites from axons. A) Multipolar B) Anaxonic C) Unipolar D) Bipolar E) Sensory
B
\_\_\_\_\_\_\_\_ neurons are short, with a cell body between dendrite and axon, and occur in special sense organs. A) Multipolar B) Anaxonic C) Unipolar D) Bipolar E) Motor
D
In a(n) \_\_\_\_\_\_\_\_ neuron, the dendrites and axon are continuous or fused. A) multipolar B) anaxonic C) unipolar D) bipolar E) interneuron
C
\_\_\_\_\_\_\_\_ neurons are the most common class in the CNS. A) Multipolar B) Anaxonic C) Unipolar D) Bipolar E) Sensory
A
\_\_\_\_\_\_\_ neurons form the afferent division of the PNS. A) Visceral sensory B) Sensory C) Neural sensory D) Somatic sensory E) Motor
B
\_\_\_\_\_\_\_\_ are the most numerous type of neuron in the CNS. A) Sensory neurons B) Motor neurons C) Unipolar neurons D) Bipolar neurons E) Interneurons
E
Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called \_\_\_\_\_\_\_\_ degeneration. A) neural B) central C) peripheral D) Wallerian E) conduction
D
Which of the following is not a function of the neuroglia? A) support B) memory C) secretion of cerebrospinal fluid D) maintenance of blood-brain barrier E) phagocytosis
B
Which of the following is a type of glial cell found in the peripheral nervous system? A) astrocytes B) satellite cells C) godgodendrocytes D) microglia E) ependymal cells
B
The largest and most numerous of the glial cells in the central nervous system are the A) astrocytes. B) satellite cells. C) oligodendrocytes. D) microglia. E) ependymal cells.
A
Functions of astrocytes include all of the following, except
A) maintaining the blood-brain barrier.
B) conducting action potentials.
C) guiding neuron development.
D) responding to neural tissue damage.
E) forming a three-dimensional framework for the CNS.
B
\_\_\_\_\_\_\_\_ account for roughly half of the volume of the nervous system. A) Axons B) Dendrites C) Neuroglia D) Synapses E) Efferent fibers
C
The function of the astrocytes in the CNS includes which of the following?
A) adjusting the composition of the interstitial fluid
B) guiding neuron development
C) maintaining the blood-brain barrier
D) repairing damaged neural tissue
E) All of the answers are correct.
E
The neuroglial cells that participate in maintaining the blood-brain barrier are the A) astrocytes. B) ependymal cells. C) microglia. D) oligodendrocytes. E) Schwann cells.
A
The myelin sheath that covers many CNS axons is formed by A) astrocytes. B) satellite cells. C) oligodendrocytes. D) microglia. E) ependymal cells.
C
\_\_\_\_\_\_\_ line the brain ventricles and spinal canal. A) Astrocytes B) Satellite cells C) Oligodendrocytes D) Microglia E) Ependymal cells
E
Small, wandering cells that engulf cell debris and pathogens in the CNS are called A) astrocytes. B) satellite cells. C) oligodendrocytes. D) microglia. E) ependymal cells.
D
The neurilemma of axons in the peripheral nervous system is formed by A) astrocytes. B) satellite cells. C) oligodendrocytes. D) microglia. E) Schwann cells
E
Glial cells that surround the neurons in ganglia are A) astrocytes. B) satellite cells. C) oligodendrocytes. D) microglia. E) ependymal cells.
B
Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because
A) oligodendrocytes form a continuous myelin sheath around the axons.
B) the endothelium of CNS capillaries forms a blood-brain barrier.
C) the neurolemma is impermeable to most molecules.
D) ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons.
E) astrocytes form a capsule around neurons.
B
Extensive damage to oligodendrocytes in the CNS could result in
A) loss of the structural framework of the brain.
B) a breakdown of the blood-brain barrier.
C) inability to produce scar tissue at the site of an injury.
D) decreased production of cerebrospinal fluid.
E) loss of sensation and motor control
E
Damage to ependymal cells would most likely affect the
A) formation of myelin sheaths.
B) formation of cerebrospinal fluid.
C) formation of ganglia.
D) repair of axons.
E) transport of neurotransmitters within axons.
B
When pressure is applied to neural tissue, all these effects are possible, except
A) a decrease in blood flow.
B) a decrease in available oxygen.
C) action potentials are generated spontaneously.
D) glial cells degenerate.
E) neurons are triggered to divide.
E
In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by
A) producing new axons.
B) regenerating cell bodies for the neurons.
C) forming a cellular cord that directs axonal regrowth.
D) clearing away cellular debris.
E) producing more satellite cells that fuse to form new axons
C
After a stroke, what type of glial cell accumulates within the affected brain region? A) Schwann cells B) satellite cells C) oligodendrocytes D) microglia E) ependymal cells
D
Which of the following interactions between electrical and chemical gradients does not lead to the establishment of a neuron’s resting potential?
A) Chemical and electrical forces both favor sodium ions entering the cell.
B) Electrical forces push sodium ions out of the cell.
C) Chemical forces tend to drive potassium ions out of the cell.
D) Potassium ions are attracted to the negative charges inside the cell.
E) Potassium ions are repulsed by positive charges outside the cell.
B
At the normal resting potential of a typical neuron, its sodium-potassium exchange pump transports
A) 1 intracellular sodium ion for 2 extracellular potassium ions.
B) 2 intracellular sodium ions for 1 extracellular potassium ion.
C) 3 intracellular sodium ions for 1 extracellular potassium ion.
D) 3 intracellular sodium ions for 2 extracellular potassium ions.
E) 3 extracellular sodium ions for 2 intracellular potassium ions.
D
Ion channels that are always open are called \_\_\_\_\_\_\_\_ channels. A) active B) gated C) leak D) regulated E) local
C
Opening of sodium channels in the axon membrane causes
A) depolarization.
B) repolarization.
C) hyperpolarization.
D) increased negative charge inside the membrane.
E) inhibition.
A
Voltage-gated channels are present A) at the motor end plate. B) on the surface of dendrites. C) in the membrane that covers axons. D) on the soma of neurons. E) along the perikaryon of neurons.
C
The sodium-potassium ion exchange pump
A) must reestablish ion concentrations after each action potential.
B) transports sodium ions into the cell during depolarization.
C) transports potassium ions out of the cell during repolarization.
D) moves sodium and potassium opposite to the direction of their electrochemical gradients.
E) depends on a hydrogen gradient for energy.
D
The equilibrium potential for potassium ion occurs at approximately A) -90 mV. B) -70 mV. C) +66 mV. D) 0 mV. E) +30 mV.
A
Any stimulus that opens \_\_\_\_\_\_\_\_ ion channel will produce a graded potential. A) a voltage-gated B) a chemically-gated C) a sodium D) a mechanically-gated E) All of the answers are correct.
E
If the permeability of a resting axon to sodium ion increases,
A) the membrane potential will repolarize.
B) the membrane potential will hyperpolarize.
C) inward movement of sodium ion will increase.
D) outward movement of sodium ion will decrease.
E) inward movement of sodium will increase and the membrane will depolarize.
E
Which of the following is not involved in creating the resting potential of a neuron?
A) diffusion of potassium ions out of the cell
B) diffusion of sodium ions into the cell
C) membrane permeability for sodium ions greater than potassium ions
D) membrane permeability for potassium ions greater than sodium ions
E) The interior of the plasma membrane has an excess of negative charges.
C
If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur, except
A) the intracellular concentration of potassium ions will increase.
B) the neuron will slowly depolarize.
C) the membrane will slowly lose its capacity to generate action potentials.
D) the inside of the membrane will have a resting potential that is more positive than normal.
E) the intracellular concentration of sodium ions will increase
A
Graded potentials
A) produce an effect that increases with distance from the point of stimulation.
B) produce an effect that spreads actively across the membrane surface.
C) may be either a depolarization or a hyperpolarization.
D) are often all-or-none.
E) cause repolarization.
C
If the potassium permeability of a resting neuron increases above the resting permeability, what effect will this have on the transmembrane potential?
A) The inside of the membrane will become more positive.
B) The inside of the membrane will become more negative.
C) There will be almost no effect on transmembrane potential.
D) The membrane will become depolarized.
E) The membrane will depolarize to threshold.
B
Ions can move across the plasma membrane in which of the following ways?
A) through voltage-gated channels as in the action potential
B) through passive or leak channels
C) by ATP-dependent ion pumps like the sodium-potassium exchange pump
D) through chemically-gated channels as in neuromuscular transmission
E) All of the answers are correct.
E
Raising the potassium ion concentration in the extracellular fluid surrounding a nerve cell will have which effect?
A) depolarize it
B) hyperpolarize it
C) increase the magnitude of the potassium equilibrium potential
D) decrease the magnitude of the potassium equilibrium potential
E) both hyperpolarize it and decrease the magnitude of the potassium equilibrium potential
E
If the axolemma becomes more permeable to potassium ion:
A) the membrane will depolarize to threshold
B) a stronger stimulus will be required to cause an action potential
C) the membrane will depolarize to +30 mV
D) sodium ions will enter the cell to replace the lost potassium ions
E) the inside of the membrane will have a positive charge
B
The following are the main steps in the generation of an action potential.
- Sodium channels are inactivated.
- Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization.
- Sodium channels regain their normal properties.
- A graded depolarization brings an area of an excitable membrane to threshold.
- A temporary hyperpolarization occurs.
- Sodium channel activation occurs.
- Sodium ions enter the cell and depolarization occurs.
The proper sequence of these events is A) 4, 6, 7, 3, 2, 5, 1. B) 4, 6, 7, 1, 2, 3, 5. C) 6, 7, 4, 1, 2, 3, 5. D) 2, 4, 6, 7, 1, 3, 5. E) 4, 2, 5, 6, 7, 3, 1.
B
The same \_\_\_\_\_\_\_\_ can have different effects depending on the properties of the \_\_\_\_\_\_\_\_. A) neurotransmitter; receptor B) receptor; neurotransmitter C) substrate; receptor D) hormone; neurotransmitter E) propagation; neurotransmitter
A
Which of the following statements about the action potential is false?
A) The rapid depolarization phase is caused by the entry of potassium ions.
B) During the repolarization phase, sodium channels close and potassium channels open.
C) During the depolarization phase, membrane potential becomes positive.
D) In the after-hyperpolarization phase, membrane potential approaches the potassium equilibrium potential.
E) Repolarization occurs as potassium ions leave the axon.
A
During repolarization of a neuron A) sodium ions move out of the cell. B) potassium ions move out of the cell. C) potassium ions move into the cell. D) both sodium and potassium ions move into the cell. E) sodium ions move into the cell.
B
How would a chemical that prevents the opening of voltage-regulated Na+ channels affect the function of a neuron?
A) neuron will only be able to hyperpolarize
B) neuron will depolarize more rapidly
C) action potentials will lack a repolarization phase
D) neuron will automatically and repeatedly produce graded potentials
E) neuron will only be capable of producing graded potentials
E
A threshold stimulus is the
A) depolarization necessary to cause an action potential.
B) peak of an action potential.
C) hyperpolarization of an axon.
D) resting potential.
E) electrical current that crosses the synaptic cleft.
A
Which of the following is true about threshold for an action potential?
A) It is more positive than the resting potential.
B) Voltage-gated potassium channels begin to close.
C) Voltage-gated potassium channels begin to open.
D) The membrane begins to hyperpolarize.
E) Threshold for a typical neuron is approximately -30 mV.
A
Which of the following does not influence the time necessary for a nerve impulse to be transmitted?
A) length of the axon
B) presence or absence of a myelin sheath
C) diameter of the axon
D) presence or absence of nodes
E) whether or not the impulse begins in the CNS
E
Which of the following types of nerve fiber possesses the fastest speed of impulse propagation? A) type A B) type B C) type C D) type D E) type E
A
Type \_\_\_\_\_\_\_\_ fibers have the largest diameter axons. A) S B) F C) A D) B E) C
C
Sensory information from skeletal muscles travels over \_\_\_\_\_\_\_\_ fibers. A) type A B) type B C) type C D) type D E) type E
A
A neuron that receives neurotransmitter from another neuron is called A) the presynaptic neuron. B) the motor neuron. C) an oligodendrocyte. D) an interneuron. E) the postsynaptic neuron.
E
Which type of synapse is most common in the nervous system? A) chemical B) electrical C) mechanical D) processing E) radiative
A
The ion that triggers the release of acetylcholine into the synaptic cleft is A) sodium. B) potassium. C) calcium. D) chloride. E) magnesium.
C
Cholinergic synapses release the neurotransmitter A) norepinephrine. B) adrenalin. C) serotonin. D) acetylcholine. E) GABA.
D
- Chemically-gated sodium channels on the postsynaptic membrane are activated.
- Calcium ions enter the synaptic terminal.
- Acetylcholinesterase hydrolyzes acetylcholine.
- An action potential depolarizes the synaptic terminal at the presynaptic membrane.
- The synaptic terminal reabsorbs choline.
- Acetylcholine is released from storage vesicles by exocytosis.
- Acetylcholine binds to receptors on the postsynaptic membrane.
- Calcium ions are removed from the cytoplasm of the synaptic terminal.
The correct sequence for these events is A) 4, 2, 6, 7, 8, 5, 3, 1. B) 4, 2, 6, 7, 1, 8, 3, 5. C) 2, 4, 6, 7, 1, 8, 3, 5. D) 2, 5, 4, 6, 7, 1, 8, 3. E) 6, 4, 2, 7, 1, 8, 3, 5.
B
If the chemically-gated sodium channels in the postsynaptic membrane were completely blocked,
A) synaptic transmission would fail.
B) release of neurotransmitter would stop.
C) smaller action potentials would result.
D) the presynaptic membrane would be unable to reach threshold.
E) the presynaptic neuron would release a different neurotransmitter.
A
The effect that a neurotransmitter has on the postsynaptic membrane depends on
A) the frequency of neurotransmitter release.
B) the nature of the neurotransmitter.
C) the characteristics of the receptors.
D) the quantity of neurotransmitters released.
E) All of the answers are correct.
E
When cholinergic receptors are stimulated,
A) sodium ions enter the postsynaptic neuron.
B) sodium ions leave the postsynaptic neuron.
C) chloride ions enter the postsynaptic neuron.
D) chloride ions leave the postsynaptic neuron.
E) norepinephrine deactivates acetylcholine
A
If the axon terminal of a motor neuron suddenly became permeable to calcium ion,
A) the neuron will fire an action potential.
B) the motor end plate will be depolarized.
C) the motor end plate will be hyperpolarized.
D) neurotransmitter release will be blocked.
E) the neuron will become unable to stimulate the muscle cell.
B
What triggers the release of acetylcholine from a synaptic terminal?
A) release of calcium ions from the synaptic vesicles
B) graded potentials in the synaptic terminal
C) synaptic vesicles fuse to dendrites
D) diffusion of sodium ions out of the synaptic terminal
E) diffusion of calcium ions into the synaptic terminal
E
Which of the following is not a possible drug effect on synaptic function?
A) interfere with neurotransmitter synthesis
B) interfere with neurotransmitter reuptake
C) prevent neurotransmitter inactivation
D) block neurotransmitter binding to receptors
E) change the type of receptor found in the postsynaptic membrane
E
After acetylcholinesterase acts, the synaptic terminal A) reabsorbs the acetylcholine. B) reabsorbs the acetate. C) reabsorbs the choline. D) reabsorbs axoplasm. E) pinches off and a new terminal grows
C
The site in the neuron where EPSPs and IPSPs are integrated is the A) chemical synapse. B) electrical synapse. C) axon hillock. D) dendritic membrane. E) synaptic terminal.
C
Presynaptic facilitation by serotonin is caused by
A) increased extracellular concentration of sodium ion.
B) increased extracellular concentration of potassium ion.
C) blockage of calcium channels in the presynaptic membrane.
D) calcium channels in the presynaptic membrane remaining open longer.
E) temporal summation
D
When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?
A) spatial summation
B) temporal summation
C) inhibition of the impulse
D) hyperpolarization
E) decrease in speed of impulse transmission
B
Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated A) spatial summation. B) temporal summation. C) inhibition of the impulse. D) hyperpolarization. E) impulse transmission.
A
The ________ division carries motor commands to muscles and glands.
efferent
Regions of the CNS where neuron cell bodies dominate constitute the ________ matter.
gray
The buildup of depolarization when EPSPs arrive in rapid succession is called ________ summation.
temporal
The buildup of depolarization when EPSPs arrive at several places on the neuron is called ________ summation.
spatial
