Chapter 11 Practice Problems - Final

e. helps to establish the resting potential of a neuron, counters the process of diffusion, and allows transport of atoms across the plasma membrane of the neuron against the concentration gradient.

Active transport a. helps establish the resting potential of a neuron. b. counters the process of diffusion. c. allows transport of atoms across the plasma membrane of the neuron against the concentration gradient. d. both helps to establish the resting potential of a neuron and counters the process of diffusion. e. helps to establish the resting potential of a neuron, counters the process of diffusion, and allows transport of atoms across the plasma membrane of the neuron against the concentration gradient.

D spinal cord.

Amyotrophic lateral sclerosis (ALS is a disease that results from nerve damage in the: A diaphragm. B intercostal muscles. C sensory nerves. D spinal cord. E brain.

d. a local change in membrane permeability caused by a greater-than-threshold stimulus.

An action potential is brought about by a. a sudden membrane impermeability. b. the movement of negatively charged proteins through the neuronal membrane. c. the movement of lipoproteins to the outer membrane. d. a local change in membrane permeability caused by a greater-than-threshold stimulus. e. all of these

c. potassium; sodium

At rest, a nerve cell has a high concentration of __________ inside and a high concentration of __________ outside. a. acetylcholine; chlorine b. sodium; potassium c. potassium; sodium d. calcium; phosphorous e. phosphorus; calcium

e. all of these

During the passage of a nerve impulse a. sodium ions pass through gated channels. b. positive feedback causes more sodium ions to enter the cell. c. the interior of the cell becomes positive. d. changing voltage increases the number of open gates. e. all of these

c. the sodium gates are shut and the potassium gates are opened.

During the recovery period between action potentials, a. the threshold value is increased. b. the threshold value is reduced. c. the sodium gates are shut and the potassium gates are opened. d. both the sodium and the potassium gates are shut. e. the nerve is said to be at the resting potential.

E repolarization

During which of the following phases of an action potential do the sodium channels close and potassium channels open, releasing potassium from the neuron? A saltatory propagation B both depolarization and repolarization C reestablishment of resting potential D depolarization E repolarization

a. a stimulus above the threshold must open sodium gates in an accelerating manner

For sodium to accumulate rapidly in a neuron, a. a stimulus above the threshold must open sodium gates in an accelerating manner b. the wave of repolarization must occur to reestablish a resting potential. c. there must be a dramatic increase in the negative charge of the cytoplasm. d. a voltage surge must cause the sodium gates to close. e. the potassium gates must open first

c. a series of changes in membrane potentials.

Functionally speaking, a nerve impulse is a. a flow of electrons along the outside of the plasma membrane of a neuron. b. the movement of cytoplasmic elements through the core of the neuron. c. a series of changes in membrane potentials. d. a lengthening and shortening of the membrane extensions of an individual neuron. e. a change in the metabolic rate within a neuron.

C motor neuron.

If a nerve impulse is traveling from the central nervous system to the organs of the body, the impulse would be traveling on a: A interneuron. B sensory neuron. C motor neuron. D ganglion. E all of the above

D. Alzheimer's disease.

Insufficient production of acetylcholine in the synapses of the brain, abnormal tangled neurons, and large deposits of beta amyloid are problems associated with: A. meningitis. B. rabies. C. epilepsy. D. Alzheimer's disease. E. Parkinson's disease.

e. all of these

Neuroglial cells a. metabolically support other neurons. b. form sheaths around neurons and control the rate of impulse transmission. c. form more than half of the volume of the brain. d. provide physical support. e. all of these

D are a type of neuroglial cell.

Oligodendrocytes are similar to Schwann cells in that they: A help neurons regenerate after injury. B conduct nerve impulses. C are located in the peripheral nervous system. D are a type of neuroglial cell. E are located in the central nervous system.

e. the opening of sodium gates and the accompanying flow of sodium ions is an example of positive feedback.

Once a threshold is reached, a. the number of sodium gates that open depends upon the strength of a stimulus. b. a graded local potential will be unable to spread to a trigger zone of the nerve membrane. c. the resting potential of a neuron is restored. d. the potassium channels in the input zone open. e. the opening of sodium gates and the accompanying flow of sodium ions is an example of positive feedback.

True

T/F: A student noticed that every time he smelled a certain perfume in the hallway, it reminded him of his mother. This is due largely to the activity of the limbic system.

True

T/F: The absolute refractory period characteristic of neurons is important in ensuring that action potentials travel in only one direction. (KNOW FOR FINAL EXAM. )

False

T/F: The nucleus and most of the organelles of a neuron are located in the dendrites.

True

T/F: The two subdivisions of the nervous system are the central nervous system and the peripheral nervous system.

a. the neuron

The basic unit of the nervous system is a. the neuron. b. neuroglia. c. the brain. d. a nerve. e. a nerve impulse.

b. sodium-potassium

The membrane-bound enzyme system that restores and maintains the resting membrane potential is which of the following pumps? a. sodium-phosphorus b. sodium-potassium c. sodium-chlorine d. phosphorus-calcium e. phosphorus-chlorine

a. switch to turn a lamp on and off.

The occurrence of an action potential can best be compared to a a. switch to turn a lamp on and off. b. volume control on a stereo. c. door to the classroom. d. room light dimmer switch.

b. nothing can stop the action potential once the threshold is reached.

The phrase "all or nothing," used in conjunction with discussion about an action potential, means that a. a resting membrane potential has been received by the cell. b. nothing can stop the action potential once the threshold is reached. c. the membrane either achieves total equilibrium or remains as far from equilibrium as possible. d. propagation along the neuron is saltatory. e. none of these

a. facilitate communication among the body systems.

The principal job of the human nervous system is to a. facilitate communication among the body systems. b. store information. c. replace or repair damaged tissues. d. provide for defense against pathogens. e. rid the body of metabolic wastes.

d. refractory period.

The recovery time from the passage of a nerve impulse is called the a. polarized response. b. wave of depolarization. c. action potential propagation. d. refractory period. e. saltatory period.

b. 70 millivolts.

The resting potential of a neuron is approximately minus a. 70 microvolts. b. 70 millivolts. c. 70 volts. d. 70 electrovolts. e. 70 megavolts.

a. axon.

The single long process that extends from a typical motor nerve cell is the a. axon. b. neuron. c. synapse. d. dendrite.

e. are expelled from the presynaptic cells and interact with membrane receptors of the postsynaptic cells

Transmitter substances a. are expelled from the presynaptic cells. b. tend to destroy acetylcholine. c. enter the presynaptic cell to continue the passage of the impulse. d. interact with membrane receptors of the postsynaptic cells. e. are expelled from the presynaptic cells and interact with membrane receptors of the postsynaptic cells

e. all of these

When a neuron is at rest a. there is a voltage difference across the membrane of about -70 millivolts. b. the interior is negatively charged. c. it is not responding to a stimulus. d. the fluid outside the membrane has more sodium and less potassium than the cytoplasm. e. all of these

d. passes from axon to dendrite.

When an impulse passes from one neuron to the next, it a. is passed directly from dendrite to axon. b. passes from axon to cell body to dendrite. c. can bypass the cell bodies of both. d. passes from axon to dendrite. e. undergoes repolarization.

b. chemical synapse

Which is a junction between two neurons? a. Schwann cell b. chemical synapse c. node d. sodium gate e. all of these

d. Energy moves ions against the concentration gradient.

Which of the following concerning transport proteins in the neuron membrane is true? a. Only sodium is transported. b. Only potassium is transported. c. Movement is in response to concentration gradients. d. Energy moves ions against the concentration gradient.

D chemically gated channels for sodium open

Which of the following events associated with the transmission of an impulse across a synapse occurs last? A neurotransmitter is released into synaptic cleft B neurotransmitter binds to receptors on postsynaptic membrane C calcium diffuses into an axon bulb D chemically gated channels for sodium open E action potential arrives at an axon bulb

b. They lie in the pathway between the interneurons and motor neurons.

Which of the following is NOT true concerning sensory neurons? a. They have receptor regions for detection of stimuli. b. They lie in the pathway between the interneurons and motor neurons. c. They relay information to the spinal cord. d. They are part of a reflex arc. e. They are one of three types of neurons.

E The synaptic cleft is a fluid-filled gap located between the presynaptic neuron and the postsynaptic neuron.

Which of the following is a true statement regarding the synapse? A Binding of the neurotransmitter to the postsynaptic neuron results in the release of magnesium into the synaptic cleft. B Neurotransmitters are stored in the dendrites of the postsynaptic neuron. C Release of a neurotransmitter results in an action potential on the presynaptic neuron. D Once released from the postsynaptic neuron, the neurotransmitter will diffuse across the synaptic cleft and bind to the presynaptic neuron. E The synaptic cleft is a fluid-filled gap located between the presynaptic neuron and the postsynaptic neuron.

D Due to actions of the sodium-potassium pump, the charge of the cytoplasm of a neuron is slightly more positive than the charge of the interstitial fluid surrounding it.

Which of the following is not true regarding the sodium-potassium pump? A The sodium-potassium pump is very important in establishing the electrical charge across the cell membrane of a neuron. B In each exchange of ions, the sodium-potassium pump removes three sodium ions from a neuron and takes in 2 potassium ions. C In a resting neuron, activities of the sodium-potassium pump result in a resting membrane potential of -70 millivolts. D Due to actions of the sodium-potassium pump, the charge of the cytoplasm of a neuron is slightly more positive than the charge of the interstitial fluid surrounding it. E Due to actions of the sodium-potassium pump, the concentration of sodium is higher outside a neuron than inside a neuron when the neuron is at rest.

a. Sodium ions enter the cell.

Which of the following is the first response a neuron makes to a stimulus? a. Sodium ions enter the cell. b. Sodium ions leave the cell. c. Potassium ions enter the cell. d. Potassium ions leave the cell.

C The neuron cannot generate an action potential.

Which of the following occurs during the absolute refractory period? A Sodium channels open, releasing sodium ions into the neuron; potassium channels close. B Potassium channels open, releasing potassium ions from the neuron; sodium channels close. C The neuron cannot generate an action potential. D Sodium and potassium channels open. E A nerve impulse is propagated.

c. An action potential continues indefinitely until a quenching signal is released.

Which statement is false? a. A nerve will not fire unless a stimulus exceeds the threshold. b. An action potential is an all-or-nothing event. c. An action potential continues indefinitely until a quenching signal is released. d. An action potential is self-propagating. e. An action potential transmission depends on activities at the membrane.

c. dendrite >>> cell body >>> axon.

Within a single neuron, the direction an impulse follows is a. dendrite >>> axon >>> cell body. b. axon >>> dendrite >>>cell body. c. dendrite >>> cell body >>> axon. d. cell body >>> dendrite >>> axon. e. cell body >>> axon >>> dendrite.