Chapter 11 Fundamentals of the Nervous System and Nervous Tissue (TB)

Direct-acting neurotransmitters ________. 

A) require cyclic AMP 
B) open ion channels to provoke rapid responses 
C) mediate very slow responses 
D) act through second messengers

Which of the following is correct relative to Ohm's law? 

A) The more intense the stimulus, the more voltage changes.
B) Current is directly proportional to the voltage. 
C) R = V + I 
D) I = R / V 

Ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid are called ________. 

A) Schwann cells 
B) astrocytes
C) oligodendrocytes 
D) ependymal cells 

The sheath of Schwann is also called the ________. 

A) myelin sheath 
B) neurilemma 
C) white matter
D) axolemma 

Bipolar neurons are commonly ________. 

A) called neuroglial cells 
B) found in ganglia 
C) motor neurons 
D) found in the retina of the eye

An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is ________. 

A) cholinesterase 
B) acetylcholine 
C) gamma aminobutyric acid
D) norepinephrine 

A neural circuit in which a single impulse is transmitted over and over is a ________. 

A) repetitive circuit
B) reverberating circuit 
C) diverging circuit 
D) converging circuit 

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. 

A) depolarization 
B) resting period 
C) repolarization 
D) absolute refractory period

A neuronal circuit that concentrates or directs a large number of incoming impulses to a rather small number of neurons is called a(n) ________. 

A) parallel circuit
B) converging circuit 
C) diverging circuit 
D) oscillating circuit 

Which of the following is not a structural feature of a neuron? 

A) axon
B) synaptic cleft 
C) dendrites 
D) Nissl bodies 

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. 

A) axon 
B) dendrite 
C) Schwann cell
D) neurolemma 

The chemically gated channel, NMDA, allows ________ ions entry into the nerve cell. 

A) K+ 
B) Ca2+ 
C) Cl-
D) Na+ 

The point at which an impulse from one nerve cell is communicated to another nerve cell is the ________. 

A) synapse 
B) effector
C) receptor 
D) cell body 

The role of acetylcholinesterase is to ________. 

A) act as a transmitting agent 
B) destroy ACh a brief period after its release by the axonal endings
C) amplify or enhance the effect of ACh 
D) stimulate the production of serotonin

Which of the following is not a function of the autonomic nervous system? 

A) innervation of cardiac muscle 
B) innervation of skeletal muscle
C) innervation of glands 
D) innervation of smooth muscle of the digestive tract 

Collections of nerve cell bodies outside the central nervous system are called ________. 

A) nerves 
B) nuclei 
C) ganglia 
D) tracts

The term central nervous system refers to the ________. 

A) brain, spinal cord, and peripheral nerves 
B) autonomic nervous system 
C) spinal cord and spinal nerves
D) brain and spinal cord 

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. 

A) neurotransmitter 
B) ion 
C) biogenic amine
D) cholinesterase 

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 

Saltatory conduction is made possible by ________. 

A) erratic transmission of nerve impulses
B) diphasic impulses 
C) the myelin sheath 
D) large nerve fibers 

Which of these ions is actively transported through the cell membrane to establish a resting potential? 

A) Cl 
B) Na 
C) Mg 
D) Ca

The part of the neuron that normally receives stimuli is called ________. 

A) a neurolemma 
B) a dendrite 
C) a Schwann cell
D) an axon 

Choose the statement that is most correct about membrane potential. 

A) Voltage would be measured by placing one electrode inside the membrane and another outside the membrane. 
B) Voltage would be measured by placing two electrodes on the exterior of the axon. 
C) Voltage would be measured by placing one electrode on the axon and grounding the other electrode.
D) Voltage would be measured by placing one electrode on one end of the axon and another electrode on the other end. 

The sodium-potassium pump ________. 

A) pumps two sodium ions inside the cell and three potassium ions outside
B) pumps three sodium ions inside the cell and two potassium ions outside 
C) pumps two sodium ions outside the cell and three potassium ions inside 
D) pumps three sodium ions outside the cell and two potassium ions inside

An action potential ________. 

A) involves the influx of negative ions to depolarize the membrane 
B) is essential for impulse propagation 
C) is initiated by potassium ion movement 
D) involves impulse propagation dependent on chemically gated ion channels

Select the correct statement about synapses. 

A) Neurotransmitter receptors are located on the axons of cells. 
B) The release of neurotransmitter molecules gives cells the property of being electrically coupled. 
C) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
D) Cells with interconnected cytoplasm are chemically coupled. 

Which of the following is a good example of a neuromodulator? 

A) acetylcholine 
B) any carbohydrate 
C) nitric oxide
D) any protein 

Which group of fibers spreads impulses at up to 1 meter per second? 

A) group B fibers 
B) group C fibers 
C) group A fibers 
D) group D fibers

The sympathetic and parasympathetic are subdivisions of the ________. 

A) somatic nervous system
B) voluntary nervous system 
C) central nervous system 
D) autonomic nervous system 

Ependymal cells ________. 

A) are a type of neuron 
B) are the most numerous of the neuroglia 
C) help to circulate the cerebrospinal fluid
D) are a type of macrophage 

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. 

A) astrocytes 
B) microglia 
C) Schwann cells
D) oligodendrocytes 

Schwann cells are functionally similar to ________. 

A) ependymal cells 
B) oligodendrocytes 
C) microglia 
D) astrocytes

Immediately after an action potential has peaked, which cellular gates open? 

A) chloride 
B) sodium 
C) potassium
D) calcium 

Nerve cell adhesion molecules (N-CAMs) ________. 

A) are crucial for the development of neural connections
B) are crucial in the production of neurotransmitters 
C) are found on "pathfinder" neurons 
D) release nerve growth factor 

An inhibitory postsynaptic potential (IPSP) is associated with ________. 

A) lowering the threshold for an action potential to occur
B) hyperpolarization 
C) opening of voltage-regulated channels 
D) a change in sodium ion permeability 

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. 

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) postsynaptic potential 
D) generator potential

All of the following are true of graded potentials except that they ________. 

A) can be called postsynaptic potentials
B) increase amplitude as they move away from the stimulus point 
C) are short-lived 
D) can form on receptor endings 

Which of the following is true about the movement of ions across excitable living membranes? 

A) Sodium gates in the membrane can open in response to electrical potential changes. 
B) Ions always move actively across membranes through leakage channels. 
C) The bulk of the solutions inside a cell are negatively charged.
D) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps. 

________ is an indolamine. 

A) Serotonin 
B) Dopamine 
C) Epinephrine 
D) Tyrosine

A second nerve impulse cannot be generated until ________. 

A) proteins have been resynthesized 
B) all sodium gates are closed
C) the Na ions have been pumped back into the cell 
D) the membrane potential has been reestablished 

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) positively charged and contains less sodium 
B) negatively charged and contains less sodium 
C) negatively charged and contains more sodium 
D) positively charged and contains more sodium

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 

Neurons may be classified according to several characteristics. Which of the following is correct? 

A) A small cross-sectional area allows shorter conduction times.
B) Group A fibers are mostly somatic sensory and motor and are the smallest in diameter. 
C) Group B fibers are highly myelinated and have the highest conduction velocities.
D) Group C fibers are not capable of saltatory conduction. 

Select the correct statement about serial processing. 

A) Memories are triggered by serial processing.
B) Input travels along several different pathways. 
C) Spinal reflexes are an example of serial processing. 
D) Smells are processed by serial pathways. 

Which of the following is not a special characteristic of neurons?

A) They are mitotic.
B) They have extreme longevity.
C) They conduct impulses.
D) They have an exceptionally high metabolic rate.

Which of the following is not a function of astrocytes? 

A) control the chemical environment around neurons
B) support and brace neurons
C) guide the migration of young neurons, synapse formation, and helping to determine capillary permeability 
D) anchor neurons to blood vessels
E) provide the defense for the CNS

Which of the following is not a chemical class of neurotransmitters?

A) ATP and other purines
B) nucleic acid
C) acetycholine
D) amino acid
E) biogenic amine

Which of the following is false or incorrect?

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

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?

A) cholinesterase
B) norepinephrine
C) gamma aminobutyric acid
D) acetylcholine

Which of the following describes the nervous system integrative function?

A) responds to stimuli by gland secretion or muscle contraction
B) analyzes sensory information, stores information, makes decisions
C) senses changes in the environment

Which of the choices below describes the ANS?

A) sensory and motor neurons that supply the digestive tract
B) 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) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
D) motor fibers that conduct nerve impulses from the CNS to skeletal muscles

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

A) leakage channel
B) ligand-gated channel
C) voltage-gated channel
D) mechanically gated channel

What is the role of acetylcholinesterase?

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

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?

A) oligodendrocytes
B) ependymal cells
C) Schwann cells
D) astrocytes

Select the correct statement regarding synapses.

A) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.
B) Cells with interconnected cytoplasm are chemically coupled.
C) Neurotransmitter receptors are located on the axons of cells.
D) The release of neurotransmitter molecules gives cells the property of being electrically coupled.

That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.

________ are found in the CNS and bind axons and blood vessels to each other.

A gap between Schwann cells in the peripheral system is called a(n) ________.

________ law is the relationship between voltage, current, and resistance.

The synapse more common in embryonic nervous tissue than in adults is the ________.

When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing.

________ potentials are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized.

________ is a disease that gradually destroys the myelin sheaths of neurons in the CNS, particularly in young adults.

When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called ________ summation.

________ is a neurotransmitter of the CNS that is used by Purkinje cells of the CNS.

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

Reflexes are rapid, automatic responses to stimuli. True or False
True False

Efferent nerve fibers may be described as motor nerve fibers. True or False
True False

Saltatory conduction occurs because of the presence of salt (NaCl) around the neuron. True or False
True False

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. True or False
True False

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. True or False
True False

During depolarization, the inside of the neuron's membrane becomes less negative. True or False
True False

Neurons in the CNS are organized into functional groups. True or False
True False

Strong stimuli cause the amplitude of action potentials generated to increase. True or False
True False

The oligodendrocytes can myelinate several axons. True or False
True False

Enkephalins and endorphins are peptides that act like morphine. True or False
True False

A synapse formed between the axon ending of one neuron and the cell body of another neuron is called an axosomatic synapse. True or False
True False

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. True or False
True False

Action potentials can be generated by virtually all cells of the body because all cells possess cell membranes. True or False
True False

Voltage is always measured between two points and may be called the potential between these two points. True or False
True False

Neurons that are far away from the center of the neuron pool and that are not easily excited by an incoming stimulus are in the discharge zone. True or False
True False

Acetylcholine is not a biogenic amine. True or False
True False

The two major classes of graded potentials are transmitter potentials and receptor potentials. True or False
True False

A graded potential that is the result of a neurotransmitter released into the synapse between two neurons is called a postsynaptic potential. True or False
True False

Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers. True or False
True False

The nodes of Ranvier are found only on myelinated, peripheral neural processes. True or False
True False

Unipolar neurons have axons structurally divided into peripheral and central processes. True or False
True False

A stimulus traveling toward a synapse appears to open calcium channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane. True or False
True False

A positive feedback cycle is the main force in the generation of graded potentials at receptor ends. True or False
True False

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them. True or False
True False