exam 4 (chapter 11)

Immediately after an action potential has peaked, which cellular gates open? a. calcium b. sodium c. chloride d. potassium

d

Which of the following are gaps found along a myelin sheath? a. terminal boutons b. axolemma c. an outer collar of perinuclear cytoplasm d. nodes of Ranvier

d

Which of the following is NOT a functional classification of neurons? a. interneurons b. sensory c. efferent d. multipolar

d

Which of the following is not characteristic of neurons? a. They have an exceptionally high metabolic rate. b. They have extreme longevity. c. They conduct impulses. d. They are mitotic.

d

Which of the following is true of axons? a. Smaller (thinner) axons are more likely to bear myelin sheaths than larger (thicker) axons. b. Axons use chemically gated ion channels to generate graded potentials. c. Neurons can have multiple axons but only one dendrite. d. A neuron can have only one axon, but the axon may have occasional branches along its length.

d

Which of the following types of neurons carry impulses away from the central nervous system (CNS)? a. sensory b. association c. afferent d. motor

d

Which part of the neuron is responsible for generating a nerve impulse? a. chromatophilic substance b. soma c. dendrite d. axon

d

An impulse from one nerve cell is communicated to another nerve cell via the ________. a. effector b. synapse c. receptor d. cell body

b

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons. a. true b. false

a

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. a. true b. false

a

Axon diameter and degree of myelination determine nerve impulse conduction velocity. a. true b. false

a

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. a. true b. false

a

Collections of nerve cell bodies outside the central nervous system are called ________. a. ganglia b. nerves c. nuclei d. tracts

a

During depolarization, the inside of the neuron's membrane becomes less negative. a. true b. false

a

Efferent nerve-fibers may be described as motor nerve fibers. a. true b. false

a

Enkephalins and endorphins are peptides that act like morphine. a. true b. false

a

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. a. true b. false

a

Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers. a. true b. false

a

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. a. true b. false

a

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. a. astrocytes b. oligodendrocytes c. Schwann cells d. microglia

a

Neurons are also called nerve cells. a. true b. false

a

Neurons in the CNS are organized into functional groups. a. true b. false

a

Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP). a. true b. false

a

Reflexes are rapid, automatic responses to stimuli. a. true b. false

a

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

a

Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor. a. true b. false

a

The __________ is due to the difference in K+ and Na+ concentrations on either side of the plasma membrane, and the difference in permeability of the membrane to these ions. a. resting membrane potential b. intermittent membrane potential c. dendrite potential d. active potential

a

The action potential is caused by permeability changes in the plasma membrane. a. true b. false

a

The oligodendrocytes can myelinate several axons. a. true b. false

a

The overlapping functions of the nervous system are sensory input, integration, and motor output. a. true b. false

a

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. a. absolute refractory period b. repolarization c. resting period d. depolarization

a

Unipolar neurons have axons structurally divided into peripheral and central processes. a. true b. false

a

What is the role of acetylcholinesterase? a. destroy ACh a brief period after its release by the axon endings b. amplify or enhance the effect of ACh c. act as a transmitting agent d. stimulate the production of acetylcholine

a

What part of the nervous system performs information processing and integration? a. central nervous system b. parasympathetic nervous system c. somatic nervous system d. sympathetic nervous system

a

What type of stimulus is required for an action potential to be generated? a. a threshold level depolarization b. multiple stimuli c. hyperpolarization d. a suprathreshold stimulus

a

Which neurotransmitter(s) is/are the body's natural pain killer? a. endorphins b. acetylcholine c. substance P d. norepinephrine

a

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? a. acetylcholine b. norepinephrine c. cholinesterase d. gamma-aminobutyric acid

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 d. greater than the excitatory, causing hyperpolarization of the membrane.

a

Which of the following is not a chemical class of neurotransmitters? a. nucleic acid b. biogenic amine c. ATP and other purines d. amino acid e. acetylcholine

a

Which of the following is not a function of the autonomic nervous system? a. innervation of skeletal muscle b. innervation of the smooth muscle of the digestive tract c. innervation of cardiac muscle d. innervation of glands

a

Which of the following is the conducting region of the neuron? a. axon b. dendrites c. terminal boutons d. soma

a

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? a. Schwann cells b. satellite cells c. astrocytes d. oligodendrocytes

a

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

a

Which pattern of neural processing works in a predictable, all-or-nothing manner, where reflexes are rapid and automatic responses to stimuli in which a particular stimulus always causes the same response? a. serial processing b. reflexive processing c. oscillative processing d. parallel processing

a

f bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them. a. true b. false

a

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

b

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 more sodium b. negatively charged and contains less sodium c. positively charged and contains more sodium d. positively charged and contains less sodium

b

Nerve cell adhesion molecules (N-CAMs) ________. a. are found on "pathfinder" neurons b. are crucial for the development of neural connections c. are crucial in the production of neurotransmitters d. release nerve growth factor

b

Strong stimuli cause the amplitude of action potentials generated to increase. a. true b. false

b

The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. a. true b. false

b

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary. a. true b. false

b

The nodes of Ranvier are found only on myelinated, peripheral neuron processes. a. true b. false

b

The sodium-potassium pump ejects two Na+ from the cell and then transports three K+ back into the cell in order to maintain the concentration gradients for sodium and potassium. a. true b. false

b

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. a. cholinesterase b. neurotransmitter c. ion d. biogenic amine

b

Unmyelinated fibers conduct impulses faster than myelinated fibers. a. true b. false

b

What component of the reflex arc determines the response to a stimulus? a. receptor b. integration center c. effector d. sensory neuron

b

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? a. mechanically gated channel b. voltage-gated channel c. leakage channel d. ligand-gated channel

b

Which neuroglia are the most abundant and versatile of the glial cells? a. ependymal cells b. astrocytes c. Schwann cells d. oligodendrocytes

b

Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing? a. diverging circuit b. reverberating circuit c. converging circuit d. parallel after-discharge circuit

b

Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)? a. diverging circuits b. reverberating circuits c. parallel after-discharge circuits d. converging circuits

b

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

b

Which of the following is NOT a type of circuit? a. diverging circuits b. pre-discharge circuits c. reverberating circuits d. converging circuits

b

Which of the following is NOT one of the chemical classes into which neurotransmitters fall? a. peptides b. chlorides c. amino acids d. gases and lipids

b

Which of the following is NOT true of an electrical synapse? a. They are less common than chemical synapses. b. They are specialized for release and reception of chemical neurotransmitters. c. Communication through these synapses may be unidirectional or bidirectional. d. Transmission across these synapses is very rapid.

b

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon? a. whether the axon is located in the central nervous system or in the peripheral nervous system. b. degree of myelination of the axon c. the number of axon collaterals extending from a truncated axon d. length of the axon

b

Which of the following is not a function of astrocytes? a. control the chemical environment around neurons b. provide the defense for the CNS c. anchor neurons to blood vessels d. support and brace neuronsguide the migration of young neurons, synapse formation, and helping to determine capillary permeability

b

Which of the following is not true of graded potentials? a. They are short-lived. b. They increase amplitude as they move away from the stimulus point. c. They can be called postsynaptic potentials. d. They can form on receptor endings.

b

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

b

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? a. acetylcholine b. endorphin c. serotonin d. nitric oxide

b

Bipolar neurons are commonly ________.called a. neuroglial cells b. found in ganglia c. found in the retina of the eye d. motor neurons

c

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. muscle contraction would occur c. the impulse would spread bidirectionally d. the impulse would move to the axon terminal only, and the muscle e. contraction would occur

c

Saltatory conduction is made possible by ________. a. erratic transmission of nerve impulses b. diphasic impulses c. the myelin sheath d. large nerve fibers

c

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. a. Schwann cell b. neurolemma c. axon d. dendrite

c

The term central nervous system refers to the ________. a. peripheral and spinal nerves b. brain, spinal cord, and peripheral nerves c. brain and spinal cord d. spinal cord and spinal nerves

c

What does the central nervous system use to determine the strength of a stimulus? a. type of stimulus receptor b. origin of the stimulus c. frequency of action potentials d. size of action potentials

c

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. a. excitatory potential b. postsynaptic potential c. generator potential d. action potential

c

Which of the choices below describes the ANS? a. 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. b. sensory and motor neurons that supply the digestive tract. 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.

c

Which of the following allows us to consciously control our skeletal muscles? a. the parasympathetic division of the autonomic nervous system b. the sympathetic division of the autonomic nervous system c. the somatic nervous system d. the afferent division of the nervous system

c

Which of the following are bundles of neurofilaments that are important in maintaining the shape and integrity of neurons? a. perikaryon b. chromatophilic substance c. neurofibrils d. axolemma

c

Which of the following correctly describes a graded potential? a. voltage regulated repolarization b. long-distance signaling c. the amplitude of various sizes d. voltage stimulus to initiate

c

Which of the following describes the excitatory postsynaptic potential? a. moves membrane potential away from threshold b. short distance hyperpolarization c. short distance depolarization d. opens K+ or Cl- channels

c

Which of the following is NOT a difference between graded potentials and action potentials? a. Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels. b. Greater stimulus intensity results in larger graded potentials, but not larger action potentials. c. Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential. d. Graded potentials occur along dendrites, whereas action potentials occur along axons.

c

Which of the following is NOT one of the basic functions of the nervous system? a. control the activity of muscles and glands b. monitor changes occurring both inside and outside the body c. regulation of neurogenesis d. integration of sensory input

c

Which of the following is NOT true of association neurons? a. Association neurons account for over 99% of the neurons in the body. b. Most association neurons are multipolar. c. Most association neurons are confined within the peripheral nervous system (PNS). d. Association neurons are also known as interneurons

c

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons? a. ependymal cells b. astrocytes c. microglia d. oligodendrocytes

c

Which of the following types of glial cells produces the myelin sheaths that insulate axons, or nerve fibers, in the central nervous system (CNS)? a. microglia b. ependymal cells c. oligodendrocytes d. astrocytes

c

A second nerve impulse cannot be generated until ________. a. all sodium gates are closed b. the Na ions have been pumped back into the cell c. proteins have been resynthesized d. the membrane potential has been reestablished

d

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

d

In multiple sclerosis, the cells that are the target of an autoimmune attack are the _________. a. neurons b. muscle cells c. Schwann cells d. oligodendrocytes

d

Schwann cells are functionally similar to ________. a. ependymal cells b. microglia c. astrocytes d. oligodendrocytes

d

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? a. oligodendrocytes b. Schwann cells c. astrocytes d. ependymal cells

d

Which criterion is used to functionally classify neurons? a. the number of processes extending from the cell body neuron b. whether the nerve fibers are myelinated or unmyelinated c. whether the neurons are found within the CNS or the PNS d. the direction in which the nerve impulse travels relative to the central nervous system

d

Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron? a. inhibitory action potential b. action potential c. inhibitory postsynaptic potential d. excitatory postsynaptic potential

d