Chp 11

Collections of nerve cell bodies outside the central nervous system are called ________. A) ganglia B) nuclei C) nerves D) tracts

A

Immediately after an action potential has peaked, which cellular gates open? A) potassium B) chloride C) calcium D) sodium

A

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________. A) negatively charged and contains less sodium B) negatively charged and contains more sodium C) positively charged and contains more sodium D) positively charged and contains less sodium

A

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. A) axon B) Schwann cell C) dendrite D) neurolemma

A

Which of the following is false or incorrect? A) A nerve impulse occurs if the excitatory and inhibitory effects are equal. B) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. C) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane.

A

Which of the following is not characteristic of neurons? A) They are mitotic. B) They have extreme longevity. C) They conduct impulses. D) They have an exceptionally high metabolic rate.

A

Which of the following is not true of graded potentials? A) They increase amplitude as they move away from the stimulus point. B) They can form on receptor endings. C) They are short-lived. D) They can be called postsynaptic potentials.

A

.Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? A) ligand-gated channel B) voltage-gated channel C) leakage channel D) mechanically gated channel

B

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. A) glial cell B) association neuron C) afferent neuron D) efferent neuron

B

A second nerve impulse cannot be generated until ________. A) proteins have been resynthesized B) the membrane potential has been reestablished C) all sodium gates are closed D) the Na ions have been pumped back into the cell

B

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________. A) the impulse would move to the axon terminal only B) the impulse would spread bidirectionally C) the impulse would move to the axon terminal only, and the muscle contraction would occur D) muscle contraction would occur

B

Nerve cell adhesion molecules (N-CAMs) ________. A) release nerve growth factor B) are crucial in the production of neurotransmitters C) are crucial for the development of neural connections D) are found on "pathfinder" neurons

B

Saltatory conduction is made possible by ________. A) erratic transmission of nerve impulses B) the myelin sheath C) diphasic impulses D) large nerve fibers

B

Schwann cells are functionally similar to ________. A) microglia B) oligodendrocytes C) ependymal cells D) astrocytes

B

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A) action potential B) excitatory potential C) generator potential D) postsynaptic potential

B

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? A) ligand-gated channel B) voltage-gated channel C) leakage channel D) mechanically gated channel

B

Which of the following describes the excitatory postsynaptic potential? A) moves membrane potential away from threshold B) short distance depolarization C) opens K+ or Cl- channels D) short distance hyperpolarization

B

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? A) gamma aminobutyric acid B) acetylcholine C) norepinephrine D) cholinesterase

B

Which of the following is not a function of astrocytes? A) guide the migration of young neurons, synapse formation, and helping to determine capillary permeability B) provide the defense for the CNS C) control the chemical environment around neurons D) support and brace neurons E) anchor neurons to blood vessels

B

Which of the following is not a function of astrocytes? A) guide the migration of young neurons, synapse formation, and helping to determine capillary permeability B) provide the defense for the CNS C) control the chemical environment around neurons support and brace neurons D) anchor neurons to blood vessels

B

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A) Specific sodium gates will open. B) A single type of channel will open, permitting simultaneous flow of sodium and potassium. C) Specific potassium gates will open. D) Sodium gates will open first, then close as potassium gates open.

B

An impulse from one nerve cell is communicated to another nerve cell via the ________. A) cell body B) receptor C) synapse D) effector

C

Bipolar neurons are commonly ________. A) found in ganglia B) motor neurons C) found in the retina of the eye D) called neuroglial cells

C

Select the correct statement regarding synapses. A) The release of neurotransmitter molecules gives cells the property of being electrically coupled. B) Neurotransmitter receptors are located on the axons terminals of cells. C) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another. D) Cells with gap junctions use chemical synapses.

C

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. A) resting period B) repolarization C) absolute refractory period D) depolarization

C

What is the role of acetylcholinesterase? A) stimulate the production of acetylcholine B) amplify or enhance the effect of ACh C) destroy ACh a brief period after its release by the axon endings D) act as a transmitting agent

C

Which of the choices below describes the ANS? A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) sensory and motor neurons that supply the digestive tract C) motor fibers that conduct nerve impulses from the CNS to skeletal muscles D) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS

C

Which of the following describes the nervous system integrative function? A) responds to stimuli by gland secretion or muscle contraction B) senses changes in the environment C) analyzes sensory information, stores information, makes decisions

C

Which of the following is not a chemical class of neurotransmitters? A) ATP and other purines B) acetycholine C) nucleic acid D) amino acid E) biogenic amine

C

Which of the following is not a function of the autonomic nervous system? A) innervation of cardiac muscle B) innervation of smooth muscle of the digestive tract C) innervation of skeletal muscle D) innervation of glands

C

Which of the following is true about the movement of ions across excitable living membranes? A) Ions always move passively across membranes. B) Ions always move actively across membranes through leakage channels. C) Sodium gates in the membrane can open in response to electrical potential changes. D) Ions always move from an area of higher concentration to an area of lower concentration

C

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? A) serotonin B) nitric oxide C) endorphin D) acetylcholine

C

An inhibitory postsynaptic potential (IPSP) is associated with ________. A) lowering the threshold for an action potential to occur B) a change in sodium ion permeability C) opening of voltage-regulated channels D) hyperpolarization

D

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. A) oligodendrocytes B) Schwann cells C) microglia D) astrocytes

D

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. A) cholinesterase B) ion C) biogenic amine D) neurotransmitter

D

The term central nervous system refers to the ________. A) peripheral and spinal nerves B) brain, spinal cord, and peripheral nerves C) spinal cord and spinal nerves D) brain and spinal cord

D

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? A) astrocytes B) oligodendrocytes C) Schwann cells D) ependymal cells

D

What does the central nervous system use to determine the strength of a stimulus? A) size of action potentials B) origin of the stimulus C) type of stimulus receptor D) frequency of action potentials

D

Which of the following correctly describes a graded potential? A) voltage regulated repolarization B) long distance signaling C) voltage stimulus to initiate D) amplitude of various sizes

D

Strong stimuli cause the amplitude of action potentials generated to increase. T/F

F

The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. T/F

F

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary. T/F

F

The nodes of Ranvier are found only on myelinated, peripheral neuron processes. T/F

F

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons. T/F

T

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane. T/F

T

Axon diameter and degree of myelination determine nerve impulse conduction velocity. T/F

T

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. T/F

T

During depolarization, the inside of the neuron's membrane becomes less negative. T/F

T

Efferent nerve fibers may be described as motor nerve fibers. T/F

T

Enkephalins and endorphins are peptides that act like morphine. T/F

T

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them. T/F

T

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. T/F

T

Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers. T/F

T

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. T/F

T

Neurons in the CNS are organized into functional groups. T/F

T

Reflexes are rapid, automatic responses to stimuli. T/F

T

Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor. T/F

T

The action potential is caused by permeability changes in the plasma membrane. T/F

T

The oligodendrocytes can myelinate several axons. T/F

T

The overlapping functions of the nervous system are sensory input, integration, and motor output. T/F

T

Unipolar neurons have axons structurally divided into peripheral and central processes. T/F

T