Chapter 10 Exam

Sodium and potassium ions cross the neuron's membrane to cause which of the following processes? a. action potential b. passive transport c. transmission d. refractory period

a. action potential

A threshold stimulation is the a. depolarization necessary to cause an action potential b. peak of an action potential c. electrical current that crosses the synaptic cleft d. hyperpolarization of an axon e. resting potential

a. depolarization necessary to cause an action potential

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

a. innervation of skeletal muscle

During repolarization of a neuron a. potassium ions move out of the cell b. both sodium and potassium ions move into the cell c. sodium ions move into the cell d. potassium ions move into the cell e. sodium ions move out of the cell

a. potassium ions move out of the cell

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

a. the membrane potential has been reestablished

Most CNS neurons lack centrioles. This observation explains a. why CHS neurons cannot regenerate b. why CHS neurons grow such long axons c. the ability of neurons to communicate with each other. d. the ability of neurons to produce a resting potential e. the ability of neurons to generate an action potential

a. why CHS neurons cannot regenerate

Some drugs modulate the activity of ion channels. For example, Novacain somewhat inhibits the opening of sodium channels. What happens to the threshold of a sensory neuron if this drug is used? a. The nerve will not function and will die off b. It will take more stimulation to reach threshold c. Threshold will not change d. It will take less stimulation to reach threshold

b. It will take more stimulation to reach threshold

Which of the following statements about the action potential is false?? a. During the depolarization phase, membrane potential becomes positive b. The rapid depolarization phase is caused by the entry of potassium ions c. Repolarization occurs as potassium ions leave the axon d. in the after-hyperpolarization phase, membrane potential approaches the potassium equilibrium potential e. During the repolarization phase, sodium channels close and potassium channels open

b. The rapid depolarization phase is caused by the entry of potassium ions

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

b. astrocytes

Functions of astrocytes include all of the following, except a. responding to neural tissue damage b. conducting action potentials c. maintaining the blood-brain barrier d. guiding neuron development e. forming a three-dimensional framework for the CNS

b. conducting action potentials

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

b. ependymal cells

Damage to ependymal cells would most likely affect the a. formation of myelin sheaths b. formation of cerebrospinal fluid c. repair of axons d. transport of neurotransmitters within axons e. formation of ganglia

b. formation of cerebrospinal fluid

If the permeability of a resting axon to sodium ion increases, a. inward movement of sodium ion will increase b. inward movement of sodium will increase and the membrane will depolarize c. outward movement of sodium ion will decrease d. the membrane potential will repolarize e. the membrane potential will hyperpolarize

b. inward movement of sodium will increase and the membrane will depolarize

Which of the following is not involved in creating the resting potential of a neuron? a. diffusion of potassium ions out of the cell b. membrane permeability for sodium ions greater than potassium ions c. The interior of the plasma membrane has an excess of negative charges d. membrane permeability for potassium ions greater than sodium ions e. diffusion of sodium ions into the cell

b. membrane permeability for sodium ions greater than potassium ions

Which of the choices below describes the ANS? a. sensory and motor neurons that supply the digestive tract b. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands c. motor fibers that conduct nerve impulse 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

b. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

Rapid impulse conduction from "node" to "node" is called a. divergent propagation b. saltatory propagation c. continuous propagation d. synaptic transmission e. spatial propagation

b. saltatory propagation

Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because a. Schwann cells form a capsule around neurons b. the astrocytes isolate the CNS by forming a blood-brain barrier c. oligodendrocytes form a continuous myelin sheath around the axons d. ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons e. the neurilemma is impermeable to most molecules

b. the astrocytes isolate the CNS by forming a blood-brain barrier

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

b. the myelin sheath

The glial cells in the central nervous system that form scar tissue after Central Nervous System injuries are the a. microglia b. oligodendrocytes c. astrocytes d. ependymal cells e. satellite cells

c. astrocytes

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

c. axon

The smallest neuroglia of the CNS that act as phagocytes are the a. astrocytes b. ependymal cells c. microglia d. oligodendrocytes e. none of the above

c. microglia

Neurons that have several dendrites and a single axon are called a. bipolar b. anaxonic c. multipolar d. unipolar e. tripolar

c. multipolar

The myelin sheath that covers many CNS axons is formed by a. satellite cells b. astrocytes c. oligodendrocytes d. microglia e. ependymal cells

c. oligodendrocytes

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

c. potassium

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

c. synapse

Where are neurotransmitters stored in a neuron? a. axon b. cell body c. synaptic knob d. dendrites

c. synaptic knob

In a(n) __________ neuron, the dendrites and axon are continuous or fused a. multipolar b. anaxonic c. unipolar d. bipolar e. none of the above

c. unipolar

_____________ neurons are short, with a cell body between dendrites and axon, and occur in special sense organs. a. Multipolar b. Anaxonic c. Unipolar d. Bipolar e. none of the above

d. Bipolar

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons? a. Action potentials would lack a repolarization phase b. The absolute refractory period would be shorter than normal c. Neurons would depolarize more rapidly d. The axon would be unable to generate action potentials e. Nonee, because the chemically-gated sodium channels would still function

d. The axon would be unable to generate action potentials

Extensive damage to oligodendryoctes in the CNS could result in a. decreased production of cerebrospinal fluid b. inability to produce scar tissue at the site of an injury c. loss of the structural framework of the brain d. loss of sensation and motor control e. a breakdown of the blood-brain barrier

d. loss of sensation and motor control

Which of the following is not a function of the neuroglia? a. secretion of cerebrospinal fluid b. maintenance of blood-brain barrier c. support d. memory e. phagocytosis

d. memory

Small, wondering cells that engulf cell debris and pathogens in the CHS are called? a. oligodendrocyytes b. astrocytes c. ependymal cells d. microglia e. satellite cells

d. microglia

The sodium-potassium ion exchange pump a. depends on the hydrogen gradient for energy b. must reestablish ion concentration after each action potential c. transports potassium ions out of the cell during repolarization d. moves sodium and potassium opposite to the direction of their electrochemical gradients

d. moves sodium and potassium opposite to the direction of their electrochemical gradients

The combined effects of inhibitory and excitatory effects on a postsynaptic cell will decide whether that cell generates an action potential. This principle is called _______. a. internalization b. potentiation c. threshold d. summation

d. summation

_________ line the brain ventricles and spinal canal a. Satellite cells b. Microglia c. oligodendrocytes d. Astrocytes e. Ependymal cells

e. Ependymal cells

The neurilemma of axons in the peripheral nervous system is formed by a. astrocytes b. satellite cells c. microglia d. oligodendrocytes e. Schwann Cells

e. Schwann Cells

The function of the astrocytes in the CNS includes which of the following? a. adjusting the composition of the interstitial fluid b. providing structural support within neural tissue c. maintaining the blood-brain barrier d. repairing damaged neural tissue e. all of the above

e. all of the above

Which of the following are types of neuroglia? a. ependymal cells b. microglia c. astrocytes d. oligodendrcytes e. all of the above

e. all of the above

Which of the following is not a function of the nervous system? a. control peripheral effectors b. integrate sensory information c. sense the internal and external environments d. coordinate voluntary and involuntary activities e. direct long-term functions, such as growth

e. direct long-term functions, such as growth

If the chemically-gated sodium channels in the postsynaptic membrane were completely blocked, a. the presynaptic neuron would release a different neurotransmitter b. the presynaptic membrane would be unable to reach threshold c. smaller action potentials would result d. release of neurotransmitter would stop e. synaptic transmission would fail

e. synaptic transmission would fail