Chapter 11 HW A&P 1

The neural circuit pattern in which the signal goes from several neurons to one is called __________. a stabilizing circuit an amplifying circuit a diverging circuit a converging circuit

a converging circuit

A bundle of axons in the PNS is called __________. a spinal cord a nerve a tract a ganglion

a nerve

A network of neurons that perform a common function is called __________. a neuronal pool neuroglia a nerve a neurofibril

a neuronal pool

The prefix ______ means "star."

astro-

Involuntary control of smooth and cardiac muscles and glands is provided by the __________. autonomic nervous system somatic motor division visceral sensory division afferent division

autonomic nervous system

The conducting region of the neuron is the: axon terminals (synaptic knobs). cell body. axon. dendrites.

axon

The brain and spinal cord compose the __________. enteric nervous system peripheral nervous system autonomic nervous system central nervous system

central nervous system

Which nervous system division is responsible for the integration of sensory information? peripheral nervous system central nervous system visceral motor division somatic motor division

central nervous system

The two structural divisions of the nervous system are the: somatic sensory division and visceral sensory system. division and motor division. visceral motor division and somatic motor division. central nervous system and peripheral nervous system.

central nervous system and peripheral nervous system.

The majority of synapses in the nervous system are: electrical. voltage. mechanical chemical.

chemical.

Action potential propagation in unmyelinated axons happens via: saltatory conduction local potentials continuous conduction synaptic transmission

continuous conduction

Which of the following is one of the mechanisms for termination of synaptic transmission? degradation of neurotransmitter by enzyme release of neurotransmitter into the synaptic cleft storage of neurotransmitter in vesicles reuptake of neurotransmitter into the postsynaptic cell

degradation of neurotransmitter by enzyme

Multiple sclerosis is an autoimmune disease that destroys myelin in the CNS. Which of the following would be a symptom of multiple sclerosis? inability to synthesize neurotransmitters increased synaptic transmission delay in neural conduction abnormally high rate of cellular division of neuroglia

delay in neural conduction

The prefix ______ means "tree" or "branch."

dendr-

The short, branched cytoplasmic extensions that allow neurons to receive input signals are called __________. axons somata synapses dendrites

dendrites

The influx of positive charges makes the membrane potential more positive and is known as: hyperpolarization. depolarization. repolarization. polarization.

depolarization.

If a stimulus opens ligand-gated sodium ion channels, the neuron will __________. hyperpolarize repolarize depolarize remain at its resting membrane potential

depolarize

Depolarization to threshold during action potential propagation in axons is due to: diffusion of Na ions up to the previous segment the axon diffusion of Na ions down to the next segment of the axon diffusion of K ions down to the next segment the axon diffusion of K ions up to the previous segment the axon

diffusion of Na ions down to the next segment of the axon

The neurotransmitter involved in emotion, motivation, and addictive behavior is __________. glycine dopamine norepinephrine substance P

dopamine

Bidirectional, instantaneous synaptic transmission is typical of __________. chemical synapses electrochemical synapses electrical synapses all synapses

electrical synapses

Which of the following moves the membrane potential of the postsynaptic neuron closer to threshold? inhibitory postsynaptic potential (IPSP) opening of potassium ion channels hyperpolarization excitatory postsynaptic potential (EPSP)

excitatory postsynaptic potential (EPSP)

Which of the following is NOT a function of neurons? integration transmitting motor information forming the myelin sheath carrying sensory information

forming the myelin sheath

Loss of K ions from the cytosol will have the same effect as: gain of Cl ions loss of Cl ions gain of Na ions gain of K ions

gain of Cl ions

Which of the following is the most important excitatory neurotransmitter in the brain? dopamine glycine glutamate GABA

glutamate

The relative refractory period is caused by: hyperpolarization inactivation of voltage-gated Na ion channels inactivation of voltage-gated K ion channels depolarization to threshold

hyperpolarization

When voltage-gated sodium ion channels are inactivated, the neuron is _________________. below threshold in the relative refractory period depolarizing in the absolute refractory period

in the absolute refractory period

Batrachotoxin produced by certain species of frogs is a toxin that permanently opens voltage-gated Na ion channels. The results of exposure to batrachotoxin will be: no depolarization increased frequency of action potentials permanent hyperpolarization inability to generate action potentials

inability to generate action potentials

If a drug inhibits the enzyme Acetylcholinesterase, the effect will be: increased ACh reuptake into presynaptic cell decreased stimulation of ACh receptors increased ACh availability in synaptic cleft increased levels of ACh inside synaptic vesicles

increased ACh availability in synaptic cleft

Nicotine is addictive because it causes dopamine-releasing neurons to fire more action potentials. Nicotine will therefore cause: decreased levels of calcium in the axon terminal increased levels of dopamine inside synaptic vesicles increased levels of dopamine in the synaptic cleft decreased stimulation of dopamine receptors

increased levels of dopamine in the synaptic cleft

Neurons that relay information within the CNS and are the location of information processing are called __________. interneurons motor neurons efferent neurons sensory neurons

interneurons

Conduction speed will be fastest in a __________. large unmyelinated axon small unmyelinated axon small myelinated axon large myelinated axon

large myelinated axon

Postsynaptic potentials are: chemical potentials resting potentials action potentials local potentials

local potentials

The prefix _______ means "small."

micro-

The small phagocytic cells that engulf debris and pathogens in the CNS are the __________. satellite cells microglia oligodendrocytes ependymal cells

microglia

The prefix ______ means "nerve."

neur-

If a neuron simultaneously receives a stimulus that results in local depolarization of 10 mV and a stimulus that results in a local hyperpolarization of 10 mV, the net effect would be: no net change in membrane potential net hyperpolarization net depolarization neurons can only receive one incoming stimulus at a time

no net change in membrane potential

Compared to chemical synapses, electrical synapses: offer faster cell-cell communication allow for unidirectional communication use different neurotransmitters involve synaptic vesicles

offer faster cell-cell communication

The prefix ______ means "few."

oligo-

Myelin for an axon is analogous to: rubber insulation for an electrical cable the battery that powers a flashlight a Band-Aid for a wound the skeleton for a body

rubber insulation for an electrical cable

The type of action potential propagation in which action potentials are only generated at nodes of Ranvier is called __________. unmyelinated conduction synaptic transmission continuous conduction saltatory conduction

saltatory conduction

Simultaneous stimulation from multiple presynaptic neurons will result in __________. spatial multiplication spatial summation temporal multiplication temporal summation

spatial summation

If a drug inhibits neurotransmitter receptors on the postsynaptic cells: there will be less neurotransmitter released the neurotransmitter will have no effect in the postsynaptic cell there will be more calcium ions in the axon terminal there will be no exocytosis of synaptic vesicles

the neurotransmitter will have no effect in the postsynaptic cell

A neurotransmitter may have an excitatory or an inhibitory effect on the postsynaptic cell, depending on __________. the quantity of neurotransmitter released the receptor to which it binds which class of neurotransmitters it belongs to the frequency of neurotransmitter release

the receptor to which it binds

During an action potential, the rapid decrease in sodium ion permeability and the simultaneous and rapid increase in potassium ion permeability is responsible for __________. the repolarization phase the hyperpolarization phase returning to the resting membrane potential after the action potential the depolarization phase

the repolarization phase

The channels that open when the axolemma reaches threshold depolarization are the: chemically gated K ion channels voltage-gated K ion channels chemically gated Na ion channels voltage-gated Na ion channels

voltage-gated Na ion channels

Place the events involved in the propagation of an action potential in the correct order of occurrence from left to right. Local current flows to axon segment AP regenerated inadjacent axon segment Axon segment depolarized to threshold Influx of Na+ Voltage-gated Na+ channels open

1. Local current flows to axon segment 2. Axon segment depolarized to threshold 3. Voltage-gated Na+ channels open 4. Influx of Na+ 5. AP regenerated inadjacent axon segment

Which of these ions triggers exocytosis of synaptic vesicles Ca2+ Cl - K+ Na+

Ca2+

_______ are branched extensions off of a neuron.

Dendrites

Sodium ions are moving in, and the membrane potential is becoming less negative than the resting membrane potential.

Depolarization

Which of the following neurotransmitters is always inhibitory? glutamate dopamine GABA acetylcholine

GABA

During an action potential, hyperpolarization is caused by: K+ efflux Na+ influx Na+ efflux K+ influx

K+ efflux

Which of the following causes the hyperpolarization phase of an action potential? Na+ influx via voltage-gated sodium ion channels K+ outflow via voltage-gated potassium ion channels Na+ outflow via voltage-gated sodium ion channels K+ influx via voltage-gated potassium ion channels

K+ outflow via voltage-gated potassium ion channels

______ are small, phagocytic cells in the central nervous system.

Microglia

Why is the resting membrane potential negatively charged? More potassium ions leak out of the neuron than move in. More potassium ions move into the neuron than leak out. Both sodium and potassium ions constantly move into the cell. More sodium ions leak out of the neuron than move in.

More potassium ions leak out of the neuron than move in.

Which of the following events will cause an EPSP? Na ions enter postsynaptic cell Cl ions enter postsynaptic cell K ions exit postsynaptic cell Ca ions exit postsynaptic cell

Na ions enter postsynaptic cell

Depolarizing local potentials are caused by an influx of: K ions via leak channels K ions via gated ion channels Na ions via leak channels Na ions via gated ion channels

Na ions via gated ion channels

The Na+/K+ pump moves __________. Na+ and K+ out of the cell Na+ out of and K+ into the cell Na+ into and K+ out of the cell ATP into the cell

Na+ out of and K+ into the cell

_______ are the supporting cells of the nervous system.

Neuroglia

_______ have fewer branches than astrocytes.

Oligodendrocytes

Potassium ions are moving out, and the membrane potential is becoming more negative as it moves back toward the resting membrane potential.

Repolarization

The cells that form the regeneration tube during neural regeneration are called __________. oligodendrocytes satellite cells Wallerian cells Schwann cells

Schwann cells

_______ are star-shaped cells.

Astrocytes

Where are synaptic vesicles located in a neuron? Axon terminals of the presynaptic neuron Axon of the presynaptic neuron Dendrites of the presynaptic neuron Dendrites of the postsynaptic neuron

Axon terminals of the presynaptic neuron

Potassium ions are moving out, and the membrane potential is becoming more negative than the resting membrane potential.

Hyperpolarization

Which of the following scenarios can increase the likelihood that a certain neuron will reach threshold and have an action potential? There are equal and consistent amounts of EPSP's as there are IPSP's in a given amount of time on a postsynaptic neuron. There is a temporal summation that causes a continuous influx of chloride anions which causes the cell to depolarize. Spatial summation of opening ligand-gated K+ ion channels and causing efflux of K+ ions until it reaches the threshold. There are equal amounts of EPSP's via spatial summation as there is temporal summation.

There are equal amounts of EPSP's via spatial summation as there is temporal summation.

Which of the following is NOT one of the mechanisms for synaptic transmission termination? Uptake of neurotransmitter into postsynaptic neuron Reuptake of neurotransmitter into presynaptic neuron Diffusion of neurotransmitter away Degradation of neurotransmitter by enzyme

Uptake of neurotransmitter into postsynaptic neuron