Chapter 12: Nervous System: Nervous Tissue

Which statement accurately compares the transmission speed of the different types of synapses? A) Transmission at chemical synapses involves a brief synaptic delay, but electrical synapses are faster. B) Transmission at both chemical and electrical synapses involves a synaptic delay of approximately 1 millisecond. C) Transmission at electrical synapses involves a brief synaptic delay, but chemical synapses are faster. D) Electrical synapses have a constant delay of 1 millisecond, but chemical synaptic delays vary between 0.1 and 0.3 millisecond.

A) Transmission at chemical synapses involves a brief synaptic delay, but electrical synapses are faster.

Conductive activity in a neuron generally causes it to secrete... A) a specific neurotransmitter that either excites or inhibits its target. B) a specific neurotransmitter that always excites its target. C) several types of neurotransmitters simultaneously, all of which excite the cell's target. D) several types of neurotransmitters simultaneously, that are broadcast to excite and inhibit multiple targets. E) several types of neurotransmitters simultaneously, that all work to prevent another immediate impulse.

A) a specific neurotransmitter that either excites or inhibits its target

The glial cell that helps to form the blood-brain barrier is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

A) astrocyte

The glial cell that provides structural support and organization to the CNS is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

A) astrocyte

What is the most abundant glial cell in the CNS? A) Astrocyte B) Ependymal cell C) Neurolemmocyte D) Microglial cell E) Oligodendrocyte

A) astrocyte

Where are synaptic knobs located? A) At the distal ends of an axons B) At the ends of dendrites C) Within the cell body D) Along axon collaterals E) At the axon hillock

A) at the distal ends of an axons

A neuron conducting an impulse from the CNS to the detrusor muscle of the urinary bladder would be classified as a(n) — neuron. A) autonomic motor B) somatic sensory C) somatic motor D) visceral sensory

A) autonomic motor

The conductive segment of a neuron is its ________, a region that contains many ________ gated channels. A) axon, voltage- B) axon, chemically C) dendrite, voltage- D) dendrite, chemically

A) axon, voltage-

The type of transport protein that moves a substance down its concentration gradient is a A) channel. B) pump.

A) channel

The main way acetylcholine is cleared from a synapse is by A) degradation by an enzyme. B) uptake by the postsynaptic cell. C) reuptake by the presynaptic cell. D) being engulfed by a supporting glial cell.

A) degradation by an enzyme

Hyperpolarization of a neuron results from A) either the entry of an anion or the exit of a cation. B) the entry of any ion. C) either the entry of a cation or the exit of an anion. D) the entrance of either sodium or potassium.

A) either the entry of an anion or the exit of a cation.

Which is not characteristic of neurons? A) high mitotic rate B) high metabolic rate C) require continuous supplies of glucose and oxygen D) extreme longevity E) none of the above

A) high mitotic rate

Which of the following is false regarding acetylcholine? A) It is rarely used in the body. B) It is the neurotransmitter used at the neuromuscular junction. C) It is stored and released by the presynaptic cell. D) It is synthesized from acetic acid and choline.

A) it is rarely used in the body

A scientist observes a particular nerve fiber that is among the fastest at conducting action potentials in the body. Which of the following best describes its likely structure? A) Large diameter and myelinated B) Large diameter and unmyelinated C) Small diameter and myelinated D) Small diameter and unmyelinated

A) large diameter and myelinated

If there were no sodium leak channels, the resting membrane potential of a neuron would be A) more negative. B) more positive. C) the same. D) 0 mV.

A) more negative

Based on structure, the most common type of neuron is the — neuron. A) multipolar B) bipolar C) unipolar D) pseudounipolar

A) multipolar

Arrival of an action potential at the synaptic knob results in A) opening of voltage-gated calcium channels and diffusion of calcium into the synaptic knob. B) opening of voltage-gated calcium channels and diffusion of calcium out of the synaptic knob to the interstitial fluid. C) closure of voltage-gated calcium channels in the synaptic knob membrane. D) opening of chemically gated calcium channels and diffusion of calcium into the synaptic knob. E) opening of chemically gated calcium channels and diffusion of calcium out of the synaptic knob to the interstitial fluid.

A) opening of voltage-gated calcium channels and diffusion of calcium into the synaptic knob.

When voltage-gated K+ channels open on the conductive segment of a neuron, A) potassium exits, repolarizing the cell to a negative value. B) potassium exits, depolarizing the cell to an even more negative value. C) potassium enters, depolarizing the cell to a positive value. D) potassium enters, repolarizing the cell to a negative value. E) potassium enters, repolarizing the cell to a positive value.

A) potassium exits, repolarizing the cell to a negative value.

The most crucial factor determining the resting potential of a neuron is the diffusion of A) potassium out of the cell through leak channels. B) potassium into the cell through gated channels. C) sodium out of the cell through leak channels. D) sodium into the cell through gated channels.

A) potassium out of the cell through leak channels.

The glial cell that protects neuron cell bodies located within ganglia is the A) satellite cell. B) ependymal cell. C) neurolemmocyte. D) astrocyte. E) oligodendrocyte.

A) satellite cell

In a mixed nerve, A) some axons transmit sensory information and others transmit motor information. B) individual axons transmit both sensory and motor information. C) chemical synapses occur along with electrical synapses. D) astrocytes are interspersed with ependymal cells.

A) some axons transmit sensory information and others transmit motor information

The glossy-white appearance of most axons is due to A) the high lipid content of the myelin sheath. B) their proximity to light-reflecting cartilage. C) their proximity to white bone. D) the white color of the perivascular feet. E) the covering of ependymal cells.

A) the high lipid content of the myelin sheath.

When transmission occurs at a synapse, neurotransmitter is released by A) the presynaptic neuron's synaptic knob into the synaptic cleft. B) the postsynaptic neuron's dendrites into the synaptic cleft. C) the presynaptic neuron's dendrites into the synaptic cleft. D) the presynaptic neuron's soma into synaptic vesicles. E) the postsynaptic neuron's telodendria into the axon hillock.

A) the presynaptic neuron's synaptic knob into the synaptic cleft.

Which is not a general function of the nervous system? A) Transporting materials throughout the body B) collecting information C) processing and evaluating information D) responding to information E) none of the above

A) transporting materials throughout the body

Action potentials are generated by the opening of ________ gated channels and they occur on the ________. A) voltage-, axon B) voltage-, dendrite C) chemically, axon D) chemically, dendrite

A) voltage-, axon

Select all the features you would expect in a nerve fiber that conducted signals slowly, such as those that control gastric secretions and other functions that are not urgent. A) Small diameter B) Unmyelinated C) Large diameter D) Myelinated

A, B

The glial cell with feet that wrap around capillaries in the CNS is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

An astrocyte

Which division of the nervous system shows a greater capacity for regeneration? A) CNS B) PNS

B) PNS

Glial cells differ from neurons in that they A) are larger and capable of meiosis. B) are smaller and capable of mitosis. C) are found only in the CNS. D) are found only in the PNS. E) transmit nerve impulses much more slowly.

B) are smaller and capable of mitosis.

In order to trigger the release of neurotransmitter from a neuron terminal, calcium ions A) exit the synaptic knob through diffusion. B) bind to proteins on the surface of synaptic vesicles. C) penetrate the synaptic vesicles and bind to molecules of neurotransmitter. D) bind to ion channels on the neuron membrane and cause them to open for the transmitter.

B) bind to proteins on the surface of synaptic vesicles.

With damage to nerve fibers, larger distances between the site of damage and the target structure innervated result in ________ chances of successful regeneration. A) increased B) decreased

B) decreased

The nervous system controls the activity of muscles and glands. Muscles and glands can generate changes and are therefore called... A) afferents B) effectors C) stimuli D) visceral

B) effectors

The glial cell that helps to circulate cerebrospinal fluid is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

B) ependymal cell

Potassium has a higher concentration A) inside the cell versus outside the cell, and sodium is also more concentrated inside versus outside the cell. B) inside the cell versus outside the cell, whereas sodium has a higher concentration outside versus inside the cell. C) outside the cell versus inside the cell, and sodium is also more concentrated outside versus inside the cell. D) outside the cell versus inside the cell, whereas sodium has a higher concentration inside versus outside the cell.

B) inside the cell versus outside the cell, whereas sodium has a higher concentration outside versus inside the cell.

A depolarization is when the inside of a neuron becomes ________ the resting membrane potential. A) more negative than B) less negative than C) closer to

B) less negative than

In a myelinated axon, the greatest concentration of voltage-gated ion channels is in the A) myelinated regions. B) neurofibril nodes.

B) neurofibril nodes.

To measure the resting potential of a neuron, a physiologist would place A) two electrodes inside the neuron. B) one microelectrode inside the neuron and another in the interstitial fluid. C) one electrode inside the cell and another inside another cell. D) one electrode inside the cell and another outside the body.

B) one microelectrode inside the neuron and another in the interstitial fluid.

The cytoplasm within a cell body of a neuron is called the A) soma. B) perikaryon. C) neurokaryon. D) chromatophilic substance. E) chromatophobic substance.

B) perikaryon

Nerves and ganglia are structures found in the... A) central nervous system B) peripheral nervous system C) central and peripheral nervous systems

B) peripheral nervous system

Most commonly, a synapse is made between a A) presynaptic neuron's dendrite and a postsynaptic membrane's cell body. B) presynaptic neuron's axon and a postsynaptic neuron's dendrite. C) presynaptic neuron's axon hillock and a postsynaptic neuron's cell body. D) presynaptic neuron's soma and a postsynaptic neuron's synaptic knob.

B) presynaptic neuron's axon and a postsynaptic neuron's dendrite

Chemically gated ion channels are mainly found in the ________ segment of a neuron. A) initial B) receptive C) conductive D) transmissive

B) receptive

A mixed nerve is one that contains both A) cranial and spinal nerve fibers. B) sensory and motor neurons. C) unipolar and bipolar neurons. D) an endoneurium and an epineurium. E) presynaptic and postsynaptic neurons.

B) sensory and motor neurons

Maintenance of appropriate ion concentrations (especially after nerve impulses that involved ion diffusion) is primarily the job of A) voltage-gated channels. B) sodium-potassium pumps. C) chemically gated channels. D) mechanically gated channels.

B) sodium-potassium pumps.

The portion of the nervous system that conducts impulses from the skin, joints, skeletal muscles, and special senses is the — division. A) autonomic motor B) somatic sensory C) somatic motor D) visceral sensory

B) somatic sensory

As a neuron's refractory period ends, its sodium channels are changing from A) their resting state to their inactivated state. B) their inactivated state to their resting state. C) their resting state to their activated state. D) their activated state to their resting state.

B) their inactivated state to their resting state.

The separation of oppositely charged ionic particles across a resting neuron's membrane results in a potential that is measured as a A) current. B) voltage. C) conductance. D) resistance.

B). Voltage

Which choice correctly orders the connective tissue wrappings of a nerve, beginning at the outermost layer? A) Perineurium → epineurium → endoneurium B) Perineurium → endoneurium → epineurium C) Epineurium → perineurium → endoneurium D) Epineurium → endoneurium → perineurium E) Endoneurium → perineurium → epineurium

C) Epineurium → perineurium → endoneurium

What do all glial cells have in common? A) They help to transmit the nerve signals. B) They transfer blood to the various neurons. C) They assist neurons in their respective functions. D) They all attack pathogens. E) They absorb extra blood and cerebrospinal fluid.

C) They assist neurons in their respective functions.

Receptors are parts of the nervous system that allow it to... A) initiate responses to information B) process information C) collect information D) conduct impulses to muscles

C) collect information

The epineurium is composed of A) dense regular connective tissue. B) simple squamous epithelium. C) dense irregular connective tissue. D) areolar connective tissue. E) pseudostratified nonkeratinized epithelium.

C) dense irregular connective tissue

Which functional class of neurons lies entirely within the central nervous system? A) Bipolar neurons B) Sensory neurons C) Interneurons D) Unipolar neurons E) Motor neurons

C) interneurons

A nerve impulse travels fastest along ________ axons of ________ diameter. A) myelinated, small B) unmyelinated, small C) myelinated, large D) unmyelinated, large

C) myelinated, large

The glial cell that myelinates and insulates axons in the peripheral nervous system is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

C) neurolemmocyte

A bipolar neuron has A) two axons extending from the cell body. B) two dendrites extending from the cell body. C) one axon and one dendrite extending from the cell body. D) a single short process that extends from the cell body and then splits into a peripheral and a central branch.

C) one axon and one dendrite extending from the cell body

The hyperpolarization that occurs at the end of an action potential is due to the prolonged A) open state of voltage-gated sodium channels. B) closure of chemically gated sodium channels. C) open state of voltage-gated potassium channels. D) closure of voltage-gated potassium channels. E) open state of chemically gated sodium channels.

C) open state of voltage-gated potassium channels.

The connective tissue wrapping that surrounds bundles (fascicles) of axons is the A) epineurium. B) endoneurium. C) perineurium. D) endosteum. E) periosteum.

C) perineurium

The function of myelin is to A) block the transmission of a nerve impulse. B) provide points of attachment for nerve threads. C) produce faster nerve impulse propagation. D) produce slow but continuous impulse conduction.

C) produce faster nerve impulse propagation.

Which part of the neuron contains the nucleus? A) Dendrite B) Axon C) Soma D) Axon hillock E) Synaptic knob

C) soma

The portion of the nervous system that has voluntary control over skeletal muscles is the — division. A) autonomic motor B) somatic sensory C) somatic motor D) visceral sensory

C) somatic motor

Which is not a function of the motor division of the nervous system? A) conducts impulses from the CNS B) transmits impulses to muscles and glands C) transmits impulses from the viscera D) voluntary control of skeletal muscle E) involuntary control of the heart

C) transmits impulses from the viscera

Continuous conduction of a nerve impulse occurs only along A) myelinated axons. B) dendrites. C) unmyelinated axons. D) axons in the PNS. E) axons in the CNS.

C) unmyelinated axons

A graded potential is one that A) is all or none (always the same intensity). B) travels the length of the nerve fiber (is long-distance). C) varies in size depending on the magnitude of the stimulus (larger voltage change for stronger stimulus). D) lasts for several seconds after ion channels have opened, closed, and reset.

C) varies in size depending on the magnitude of the stimulus (larger voltage change for stronger stimulus).

Spinal nerves extend from the spinal cord, whereas — nerves extend from the brain.

Cranial

Typically, the resting membrane potential of a neuron is A) 7 V. B) 700 mV. C) −7 V. D) −70 mV. E) 0 mV.

D) -70 mV

Choose the answer that correctly lists, in chronological order, the events involved in synaptic transmission. a: A nerve impulse reaches the synaptic knob. b: Neurotransmitter molecules diffuse across the synaptic cleft. c: A nerve impulse begins in the postsynaptic cell. d: Neurotransmitter molecules bind to receptors in the postsynaptic cell. e: A voltage change occurs in the postsynaptic cell. A) a, c, b, d, e B) a, b, e, d, c C) c, b, d, e, a D) a, b, d, e, c E) c, a, b, d, e

D) a, b, d, e, c

The endoneurium is composed of A) dense regular connective tissue. B) simple squamous epithelium. C) dense irregular connective tissue. D) areolar connective tissue. E) pseudostratified nonkeratinized epithelium.

D) areolar connective tissue.

There are two types of synapses, based on mode of communication. What are they? A) Mechanical and chemical B) Magnetic and physical C) Physical and chemical D) Chemical and electrical E) Mechanical and electrical

D) chemical and electrical

The glial cell that defends the body against pathogens is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

D) microglial cell

As an axon approaches the cell onto which it will terminate, it generally branches repeatedly into several A) teloaxons. B) dendrites. C) collateral axons. D) telodendria. E) neurolemmocytes.

D) telodendria

A neuron conducting an impulse from the stomach wall to the CNS would be classified as a(n) — neuron. A) autonomic motor B) somatic sensory C) somatic motor D) visceral sensory

D) visceral sensory

Electrical signals are conducted toward the cell body of a neuron by its —

Dendrites

Of the two types of synapses, based on mode of communication, which is less common but allows faster signal transmission? A) Chemical synapse B) Mechanical synapse C) Physical synapse D) Magnetic synapse E) Electrical synapse

E) electrical synapse

Based on function, the vast majority of neurons are A) sensory neurons. B) motor neurons. C) unipolar neurons. D) bipolar neurons. E) interneurons.

E) interneurons

The neurons that are responsible for integrating information by retrieving, processing, storing, and "deciding" how the body responds to stimuli are A) sensory neurons. B) motor neurons. C) accessory neurons. D) correlation neurons. E) interneurons.

E) interneurons

A nerve A) contains a single axon. B) is found only in the CNS. C) carries only sensory information. D) carries information only toward the PNS. E) is a cablelike bundle of parallel axons.

E) is a cablelike bundle of parallel axons.

The glial cell that myelinates and insulates axons within the CNS is the A) astrocyte. B) ependymal cell. C) neurolemmocyte. D) microglial cell. E) oligodendrocyte.

E) oligodendrocyte

The afferent division of the nervous system is also known as the — division A) motor B) cranial C) ganglial D) efferent E) sensory

E) sensory

The motor nervous system is also known as the — nervous system.

Efferent

True or false: A sensory neuron detecting an intense stimulus will generate action potentials of greater strength as compared to a sensory neuron detecting a weak stimulus.

False

True or false: As the distance between a damaged axon and its receptor organ increases, the possibility of repair increases.

False

True or false: Graded potentials generally occur only on the axon of a neuron.

False

True or false: In the CNS all axons are myelinated, but in the PNS some are myelinated and some are unmyelinated.

False

True or false: The nervous system contains more neurons than glial cells.

False

True or false: Transmission of nerve impulses along myelinated axons requires more energy than transmission along unmyelinated axons.

False

True or false: Voltage-gated potassium channels in a neuron's axon are triggered to open when membrane potential becomes more negative.

False

The axon hillock makes up the — segment of a neuron.

Initial

Along an axon, the gaps between neurolemmocytes are called neurofibril —

Nodes

True or false: A neuron's membrane contains more potassium leak channels than sodium leak channels.

True

True or false: Acetylcholine is a neurotransmitter frequently used in the autonomic nervous system.

True

True or false: An action potential involves a temporary reversal of polarity across the plasma membrane (that is, the inside of the axon becomes relatively positive compared to the interstitial fluid).

True

True or false: Glial cells help maintain the structure of synapses and they can modify neural transmission.

True

True or false: Negatively charged protein molecules are more prevalent within a neuron's cytosol than in the interstitial fluid.

True

True or false: Neurotransmitter is released from the synaptic knob by exocytosis, and it then diffuses across the synaptic cleft.

True

True or false: Typically, a multipolar neuron has many dendrites and one axon extending from the cell body.

True

True or false: Voltage-gated sodium channels at a neuron's initial segment are triggered to open when the membrane becomes more positive.

True

True or false: chemical synapses are more common than electrical synapses

True

True or false: the spinal cord is part of the central nervous system.

True