Deck 12: Nervous Tissue

Question 1

In a myelinated fiber only the initial segment in the trigger zone have voltage-regulated channels.

Answer 1

False

Question 2

are examples of effectors of the nervous system.

A)Receptors
B)Stimuli
C)Reflexes
D)Glands
E)Sense organs

Answer 2

D

Question 3

Nitric oxide (NO) acts as a neuromodulator by altering synaptic function.

Answer 3

True

Question 4

Unipolar neurons have only a single process leading away from the soma.

Question 5

Acetylcholine triggers the synthesis of the second messenger cAMP only in neurons of the PNS.

Question 6

Norepinephrine is a monoamine.

Question 7

Neurons move material away from the soma by retrograde transport.

Question 8

Ependymal cells line the inner cavities of the CNS.

Question 9

An action potential never occurs in dendrites.

Question 10

When a neuron is stimulated, Na+ gates open and allow Na+ to exit the cell.

Question 11

Most neurons have multiple dendrites.

Question 12

The nervous system employs exclusively electrical means to send messages, whereas the endocrine system communicates by means of chemical messengers.

Question 13

Oligodendrocytes serve the same purpose in the CNS that satellite cells do in the PNS.

Question 14

Any two EPSPs will override one IPSP.

Question 15

The autonomic nervous system is also called the

A)visceral sensory division.
B)somatic sensory division.
C)visceral motor division.
D)somatic motor division.
E)central nervous system.

Question 16

division carries signals to the smooth muscle in the large intestine.

A)Visceral sensory
B)Somatic sensory
C)Visceral motor
D)Somatic motor
E)Afferent

Question 17

Nerves are of the nervous system.

A)organs
B)tissues
C)organ systems
D)organelles
E)cells

Question 18

The division tends to prepare the body for action.

A)sensory afferent
B)motor afferent
C)somatic motor
D)parasympathetic
E)sympathetic

Question 19

Memories are formed by neural pathways of modified synapses.

Question 20

In the brain, neurons are more abundant than neuroglia.

Question 21

Conduction speed of a nerve fiber would be the fastest in a

A)large myelinated fiber.
B)small myelinated fiber.
C)large unmyelinated fiber.
D)small unmyelinated fiber.
E)small fiber with multiple Schwann cells.

Question 22

About 90% of the neurons in the nervous system are neurons.

A)sensory
B)motor
C)afferent
D)efferent
E)association

Question 23

Most local potentials happen at the

A)dendrites.
B)somas.
C)axon hillock.
D)trigger zone.
E)Schwann cells.

Question 24

Opening of sodium gates typically leads to

A)repolarization of the plasma membrane.
B)hyperpolarization of the plasma membrane.
C)depolarization of the plasma membrane.
D)drifting of plasma membrane voltage toward a more negative value.
E)plasma membrane voltage returning to the resting membrane potential.

Question 25

neurons are the most common type of neurons.

A)Multipolar
B)Bipolar
C)Unipolar
D)Anaxonic
E)Dendritic

Question 26

Nerve fiber refers to

A)a nerve cell.
B)an organelle in nerve cells.
C)an organ.
D)an axon.
E)a bundle of macromolecules in nerve cells.

Question 27

In order for a peripheral nerve fiber to regenerate it must have

A)all dendrites intact.
B)at least half the length of the fiber intact.
C)at least the entire axon and neurilemma intact.
D)the soma and at least some neurilemma intact.
E)at least part of the soma intact.

Question 28

This image shows a representative neuron.What does "1" represent?

A)synaptic knobs
B)axons
C)dendrites
D)interneurons
E)axon collaterals

Question 29

An inhibitory local potential

A)depolarizes the plasma membrane.
B)hyperpolarizes the plasma membrane.
C)repolarizes the plasma membrane.
D)neutralizes the plasma membrane.
E)drifts the membrane potential towards the resting membrane potential.

Question 30

has the greatest influence on the resting membrane potential.

A)Sodium
B)Chloride
C)Calcium
D)Phosphate
E)Potassium

Question 31

form myelin in the spinal cord.

A)Schwann cells
B)Astrocytes
C)Satellite cells
D)Oligodendrocytes
E)Microglia

Question 32

While the membrane is depolarizing its

A)chloride gates are partially open.
B)chloride gates are fully open.
C)potassium gates are fully open.
D)sodium gates are partially open.
E)sodium gates are fully open.

Question 33

Some neurons are specialized to detect stimuli, whereas neurons send signals to the effectors of the nervous system.

A)efferent; afferent
B)afferent; efferent
C)motor; sensory
D)efferent; association
E)afferent; association

Question 34

The myelin sheath is formed by

A)fibers.
B)cells.
C)macromolecules.
D)polymers.
E)organelles.

Question 35

Local potentials are , meaning they vary in magnitude according to the strength of the stimulus.

A)graded
B)reversible
C)decremental
D)excitatory
E)inhibitory

Question 36

Which of the following will cause the plasma membrane to hyperpolarize when at its RMP?

A)inflow of sodium
B)inflow of potassium
C)inflow of calcium
D)inflow of chloride
E)outflow of chloride

Question 37

This image shows a representative neuron.What does "5" represent?

A)synaptic knobs
B)Schwann cells
C)trigger zone
D)node of Ranvier
E)axon collateral

Question 38

Most metabolic and regulatory functions in a neuron happen at the

A)axon.
B)soma.
C)dendrites.
D)axon hillock.
E)Schwann cell.

Question 39

Most of the myelin sheath is composed of

A)lipids.
B)carbohydrates.
C)glycoproteins.
D)proteins.
E)polysaccharides.

Question 40

are the primary site for receiving signals from other neurons.

A)Synaptic knobs
B)Axons
C)Axon collaterals
D)Somas
E)Dendrites

Question 41

excites skeletal muscle and inhibits cardiac muscle.

A)Norepinephrine
B)Dopamine
C)Histamine
D)Acetylcholine
E)β-endorphin

Question 42

binds to ligand-regulated gates, and is the most common inhibitory neurotransmitter in the brain.

A)γ-aminobutyric acid (GABA)
B)Noradrenaline
C)Epinephrine
D)Acetylcholine
E)Norepinephrine

Question 43

A cholinergic synapse employs as its neurotransmitter.

A)monoamine
B)acetylcholine
C)epinephrine
D)norepinephrine
E)catecholamine

Question 44

All of the following are typical characteristics of neurotransmitters except

A)they are synthesized by a presynaptic neuron.
B)they are released in response to stimulation.
C)they are released into the bloodstream before reaching the postsynaptic cell.
D)they bind to specific receptors on the postsynaptic cell.
E)they alter the physiology of the postsynaptic cell.

Question 45

Which of these happens first in an adrenergic synaptic transmission?

A)ATP is converted to cyclic AMP
B)adenylate cyclase is activated
C)G protein dissociates from the NE receptor
D)G protein binds to adenylate cyclase
E)cyclic AMP induces several effects in the cell

Question 46

When the voltage of a plasma membrane shifts from +35mV towards 0 mV, we say the cell is

A)depolarizing.
B)repolarizing.
C)hyperpolarizing.
D)reaching the threshold.
E)exiting the threshold.

Question 47

Some antidepressant drugs act by inhibiting monoamine oxidase (MAO), which is an enzyme

A)that binds to chloride gates.
B)that breaks down monoamines.
C)that blocks sodium channels.
D)that converts ATP to cyclic AMP.
E)that degrades acetylcholine.

Question 48

During hyperpolarization (or afterpotential)

A)sodium ions are entering the cells.
B)sodium ions are leaving the cell.
C)potassium ions are entering the cell.
D)potassium ions are leaving the cell.
E)both sodium and potassium ions are leaving the cell.

Question 49

During the absolute refractory period

A)if a neuron reaches threshold, the action potential goes to completion.
B)the neuron fires at its maximum voltage if a stimulus depolarizes the neuron to threshold.
C)the signal grows weaker with distance.
D)it is possible to trigger a new action potential, but only with an unusually strong stimulus.
E)no stimulus of any strength will trigger a new action potential.

Question 50

What would be the best explanation for why myelinated fibers conduct signals faster than unmyelinated fibers?

A)There are no internodes in unmyelinated fibers.
B)There are more internodes in unmyelinated fibers.
C)Facilitated diffusion of sodium and potassium is faster in myelinated fibers.
D)Active transport of sodium and potassium is faster in myelinated fibers.
E)Diffusion of ions along the axoplasm is faster.

Question 51

Which of these is an example of an EPSP in a typical neuron?

A)a voltage change from 0 mV to +0.35 mV
B)a voltage change from -70 mV to -69.5 mV
C)a voltage change from -69.5 mV to -70 mV
D)a voltage change from +35 mV to 0 mV
E)a voltage change from -70 mV to -70.5 mV

Question 52

Inhibitory postsynaptic potentials (IPSPs) are associated with

A)depolarization of the cell membrane.
B)repolarization of the cell membrane.
C)hyperpolarization of the cell membrane.
D)no change of the cell membrane potential.
E)no change of the threshold.

Question 53

All of these contribute to the cessation of the signal in a synaptic transmission except

A)synaptic vesicles secrete neurotransmitter by exocytosis.
B)neurotransmitter escapes from the synapse into the nearby extracellular fluid.
C)neurotransmitters stop being released.
D)the synaptic knob reabsorbs some neurotransmitters by endocytosis.
E)enzymes in the postsynaptic cell break down some neurotransmitters.

Question 54

This image shows an action potential.What does "6" represent?

A)a critical voltage called threshold
B)hyperpolarization of the membrane
C)depolarization of the membrane
D)repolarization of the membrane
E)resting membrane potential

Question 55

This image shows an action potential.What does "1" represent?

A)a rising local potential
B)a critical voltage called threshold
C)hyperpolarization of the membrane
D)repolarization of the membrane
E)resting membrane potential

Question 56

A neuron can receive thousands of EPSPs from different neurons, and responds by triggering or not triggering an action potential.This addition and response to the net effect of postsynaptic potentials is called

A)temporal summation.
B)neural summation.
C)spatial summation.
D)neuronal coding.
E)recruitment.

Question 57

Local potentials are , whereas action potentials are .

A)irreversible; reversible
B)self-propagating; local
C)graded; all or none
D)nondecremental; decremental
E)produced by voltage-regulated channels; produced by gated channels

Question 58

A traveling wave of excitation is what we know as

A)a local potential.
B)a graded potential.
C)an action potential.
D)a nerve signal.
E)a depolarizing signal.

Question 59

Opening of gates produces an .

A)chloride; IPSP
B)sodium; IPSP
C)calcium; IPSP
D)potassium; EPSP
E)calcium and sodium; IPSP

Question 60

Which of these happens first in an cholinergic synaptic transmission?

A)acetylcholine diffuses across the synaptic cleft
B)postsynaptic potential is produced
C)sodium enters the postsynaptic cell
D)synaptic vesicles release acetylcholine
E)acetylcholine binds to ligand-regulated gates

Question 61

Presynaptic inhibition is the opposite of

A)coding.
B)integration.
C)recruitment.
D)summation.
E)facilitation.

Question 62

The best type of neural pool for producing a prolonged output is

A)a converging circuit.
B)a diverging circuit.
C)a reverberating circuit.
D)a presynaptic pool.
E)an autonomic pool.

Question 63

Accumulation of Ca₂+ in the synaptic knob is called , and probably plays an important role in .

A)synaptic facilitation; short-term memory
B)neural coding; immediate memory
C)postsynaptic potential; long-term memory
D)neural coding; short-term memory
E)long-term potentiation; long-term memory

Question 64

Parkinson disease is a progressive loss of motor function due to the degeneration of specific neurons. These neurons secrete an inhibitory neurotransmitter that prevents excessive activity in motor centers of the brain.This neurotransmitter is

A)serotonin.
B)dopamine.
C)acetylcholine.
D)GABA (γ-aminobutyric acid).
E)glutamate (glutamic acid).

Question 65

Even though all action potentials are the same, the brain can differentiate a variety of stimuli by source and intensity.The mechanism by which the nervous system converts these action potentials into meaningful information is called neural

A)recruitment.
B)pooling.
C)integration.
D)facilitation.
E)coding.