Chapter 11

The sodium/potassium pump moves ______ sodium out for every _______ potassium in.

3, 2

How would an increased extracellular K+ concentration affect K+ diffusion at leakage (nongated) channels and the membrane potential?

A decrease in the electrochemical gradient would reduce K+ leak so cells would be less negative (more depolarized).

Indicate, by letter, where one would find short-distance signals called graded potentials that travel toward the cell body. A. dendrites B. soma C. axon D. axon terminals

A. dendrites

Which letter matches the process(es) of the neuron that provide(s) an enormous surface area for receiving signals from other neurons? A. dendrites B. cell body C. axon D. axon terminals

A. dendrites

Which statement best describes the all-or-none principle?

An action potential happens completely, or it doesn't happen at all.

Which fiber type consists of small diameter, unmyelinated axons, that propagate nerve impulses slowly?

Group C fibers

Which of the following describes a change of membrane potential from -70mV to -75mV?

Hyperpolarization

Which of the following types of glial cells are the most abundant and versatile and aid in making exchanges between capillaries and neurons? a) Ependymal cells b) Schwann cells c) Microglial cells d) Astrocytes e) Oligodendrocytes

d) Astrocytes

Somatic motor fibers carry information from the _______. a) skin, skeletal muscles, and joints to the CNS b) organs in the ventral body cavity to the CNS c) CNS to smooth muscles, cardiac muscles, and glands d) CNS to skeletal muscles

d) CNS to skeletal muscles

Which of the following does not describe the function of the structure labeled (B)? a) Receptive region of the neuron b) Major biosynthetic center of the neuron c) Major metabolic center of the neuron d) Conductive region of the neuron

d) Conductive region of the neuron

__________ are the most common structural type of neuron in humans. a) Pseudounipolar b) Unipolar c) Bipolar d) Multipolar

d) Multipolar

Pictured is a cross section of a myelinated axon in the peripheral nervous system (PNS). Which glial cell type produces the myelin sheath, indicated by the arrow, in the PNS? a) Astrocyte b) Oligodendrocyte c) Satellite cell d) Schwann cell

d) Schwann cell

Cilia (Select all that apply) o are not allowed in the central nervous system. o are found on ependymal cells. o move substances across membrane surfaces. o are used for absorption.

o are found on ependymal cells. o move substances across membrane surfaces.

Astrocytes (Select all that apply) o are the most common of the glial cells. o absorb excess K+ to help maintain membrane potential. o guide migration of the neurons. o help process information in the brain.

o are the most common of the glial cells. o absorb excess K+ to help maintain membrane potential. o guide migration of the neurons. o help process information in the brain.

The sodium-potassium ion pump will __________.

pump three sodium ions out of the cell for every two ions of potassium it brings into the cell

The point marked 3, on the figure, can be described as __________.

representing the portion of the action potential, where Na+ entry depolarizes the neuron, opening up additional voltage-dependent Na+ channels that allow in even more Na+

A stimulus that fails to generate an action potential is called a ________.

subthreshold stimulus

If we consider neurons to be carrying on conversations, which portion(s) of the neuron "listen(s)?" (A) dendrites only (A) dendrites and (B) cell body (B) cell body only (D) axon terminals

(A) dendrites and (B) cell body

Which type of ion channel opens when a neurotransmitter binds to it?

Chemically gated (ligand-gated) channels

In the figure above, which letter(s) correspond(s) to the peripheral nervous system? A. Sensory input B. Integration C. Motor output D. Both A and C represent portions of the peripheral nervous system (PNS). E. All of the labels represent portions of the peripheral nervous system (PNS).

D. Both A and C represent portions of the peripheral nervous system (PNS).

If we consider neurons to be carrying on conversations, which portion of the neuron "speaks" by releasing neurotransmitters? A. dendrite B. cell body C. axon D. axon terminal

D. axon terminal

Which structure is the secretory region of the neuron? A. dendrites B. cell body C. axon D. axon terminal

D. axon terminal

Na+ channels open during which of the following events?

Depolarization phase of an action potential

Which statement best describes the role of leakage (nongated) channels?

Leakage channels help maintain the resting membrane potential.

Which of the following could cause a graded depolarization?

Na+ entering the cell through chemically gated channels

I know I said the K+ is rushing in-it's not it's rushing OUT! The Na+/K+ pump already put it in!

OK-got it!

Which of the following results if the neuron is stimulated at the time point indicated by the arrow?

The neuron cannot respond to another stimulus, no matter how strong, because this time point is within the absolute refractory period.

Which of the following best describes the event that triggers an action potential in a neuron?

Threshold stimulus

Which of the following membrane ion channels open and close in response to changes in the membrane potential?

Voltage-gated channels

Identify the correctly classified neurons. a) Almost all interneurons are multipolar and most are confined within the CNS. b) Motor neurons are multipolar and carry impulses into the CNS. c) Virtually all sensory neurons are unipolar and transmit impulses away from the CNS. d) Association neurons are bipolar and most are part of the special senses.

a) Almost all interneurons are multipolar and most are confined within the CNS.

Which of the following neuroglia is most responsible for helping determine capillary permeability in nervous tissue? a) Astrocytes b) Ependymal cells c) Oligodendrocytes d) Schwann cells e) Microglial cells

a) Astrocytes

Which of the following types of glial cells line the central cavities of the brain and spinal cord, where they help to circulate the cerebrospinal fluid? a) Ependymal cells b) Oligodendrocytes c) Astrocytes d) Schwann cells e) Microglial cells

a) Ependymal cells

Which way does afferent go? a) In b) Out c) Across

a) In

Which of the following is not true of motor (efferent) neurons? a) Motor (efferent) neurons are bipolar. b) The cell bodies of most motor (efferent) neurons are located in the CNS. c) Impulses from motor (efferent) neurons cause activity in skeletal muscles and glands. d) Motor (efferent) neurons carry impulses away from the CNS to the effector organs.

a) Motor (efferent) neurons are bipolar.

Interneurons and motor neurons are which of the following? a) Multipolar neurons b) Pseudounipolar neurons c) Unipolar neurons d) Bipolar neuron

a) Multipolar neurons

Based on your understanding of this cell's function, diseases such as multiple sclerosis, that damage the myelin sheath of neurons, likely affect which of the cells in the figure? a) Oligodendrocyte, which is depicted by (d) b) Ependymal cell, which is depicted by (c) c) Astrocyte, which is depicted by (c) d) Astrocyte, which is depicted by (a) e) Microglial cell, which is depicted by (b) f) Oligodendrocyte, which is depicted by (a)

a) Oligodendrocyte, which is depicted by (d)

Complete the following analogy: Electrical wire is to electrical insulating tape as peripheral neurons are to __________. a) Schwann cells b) oligodendrocytes c) astrocytes d) ependymal cells

a) Schwann cells

Which statement is true of the glial cell pictured above? a) This glial cell has processes that touch nearby neurons, monitoring their health, and when this glial cell senses that certain neurons are injured or in other trouble, this microglial cell migrates toward them. b) This glial cell has numerous radiating processes that cling to neurons and their synaptic endings, and cover nearby capillaries. c) This glial cell forms a fairly permeable barrier between the cerebrospinal fluid that fills cavities of the brain and the tissue fluid bathing the cells of the CNS. d) This glial cell lines up along the thicker nerve fibers in the CNS and wraps its processes tightly around the fibers, producing an insulating covering called a myelin sheath.

a) This glial cell has processes that touch nearby neurons, monitoring their health, and when this glial cell senses that certain neurons are injured or in other trouble, this microglial cell migrates toward them.

Microglial are the "immune system" of the central nervous system. a) True b) False

a) True

In considering the types of neurons and their predominant functions, efferent is to multipolar as __________. a) afferent is to unipolar b) afferent is to interneuron c) efferent is to sensory neuron d) afferent is to motor neuron

a) afferent is to unipolar

An appropriate label for B in the figure shown here could also be the ________. a) central nervous system b) spinal nerves c) peripheral nervous system d) cranial nerves

a) central nervous system

Match the system with its correct description: The central nervous system __________. a) consists of the brain and spinal cord b) consists of cranial and spinal nerves carrying impulses to and from the brain and spinal cord c) conducts impulses from the brain and spinal cord to skeletal muscles d) conducts impulses from the brain and spinal cord to internal organ muscles

a) consists of the brain and spinal cord

As a general rule of thumb, the greater the potential difference in charge between two points, the __________ the voltage. a) higher b) lower c) less difference in d) more even

a) higher

What part of the neuron is a process that can generate and conduct action potentials?

axon

Which of the pictured cell types influences neuronal function by "mopping up" leaked potassium ions and by recapturing and recycling released neurotransmitters? These cells also participate in information processing in the brain. a) Oligodendrocyte, which is depicted by (d) b) Astrocyte, which is depicted by (a) c) Oligodendrocyte, which is depicted by (a) d) Ependymal cell, which is depicted by (c) e) Microglial cell, which is depicted by (b)

b) Astrocyte, which is depicted by (a)

From where can collaterals emerge on a myelinated nerve? a) From the neuron hillock b) At the myelin sheath gaps (nodes of Ranvier) c) At the terminal of the axon d) From the dendrite

b) At the myelin sheath gaps (nodes of Ranvier)

You are driving and see a red light ahead. Your nervous system indicates "stop", and your foot hits the brake. Which portion of the nervous system, as indicated in the figure, is responsible for the decision to stop? a) C. Motor output b) B. Integration c) D. Muscle systems d) A. Sensory input

b) B. Integration

Which of the following belongs to the central nervous system? (Select all that apply) a) Spinal Nerves b) Brain c) Cranial nerves d) Spinal Cord

b) Brain d) Spinal Cord

What is the difference between nerves and tracts? a) Tracts are bundles of neuron processes and nerves are the conducting regions of neurons. b) Bundles of axons are called tracts in the CNS and nerves in the PNS. c) Tracts are composed of many nerves wrapped into long, rope-like extensions. d) Bundles of axons are called nerves in the CNS and tracts in the PNS.

b) Bundles of axons are called tracts in the CNS and nerves in the PNS.

Somatic motor fibers carry information from the _______. a) organs in the ventral body cavity to the CNS b) CNS to skeletal muscles c) skin, skeletal muscles, and joints to the CNS d) CNS to smooth muscles, cardiac muscles, and glands

b) CNS to skeletal muscles

Based on your understanding of this cell's function, you might expect this cell to be active in neurodegenerative disorders like Alzheimers where this cell removes damaged neurons. Additionally, this cell is active in preventing encephalitis and meningitis due to its ability to phagocytize microorganisms. a) Astrocyte, which is depicted by (b) b) Microglial cell, which is depicted by (b) c) Oligodendrocyte, which is depicted by (d) d) Microglial cell, which is depicted by (c) e) Astrocyte, which is depicted by (a)

b) Microglial cell, which is depicted by (b)

OK silly joke! Which is worse being on my last nerve or my last neuron? a) Nerve b) Neuron

b) Neuron

Which of the following is not a characteristic of neurons? a) Neurons require continuous and abundant supplies of oxygen, and cannot survive for more than a few minutes without it. b) Neurons are relatively small, simple-structured cells. c) Neurons can function optimally for over 100 years. d) In general, neurons cannot be replaced if destroyed.

b) Neurons are relatively small, simple-structured cells.

Cell body clusters in the CNS are a) Ganglia b) Nuclei c) Impossible

b) Nuclei

Which of the following terms is correctly matched with its definition? a) Ganglion: a collection of neuron cell bodies in the brain b) Nucleus: a collection of neuron cell bodies in the CNS c) Tract: a bundle of axons in the PNS d) Nerve: a bundle of axons in the spinal cord

b) Nucleus: a collection of neuron cell bodies in the CNS

Which type of axonal transport allows certain viruses to circumvent the barrier created by astrocytes to enter into the CNS? a) Anterograde transport b) Retrograde transport c) All axonal transport d) Synaptic transport

b) Retrograde transport

Which of the following characteristics is not associated with a myelinated nerve fiber in the peripheral nervous system? a) Rapid conduction of nerve impulses b) Slow conduction of nerve impulses c) Formed by Schwann cells d) The presence of myelin sheath gaps (nodes of Ranvier)

b) Slow conduction of nerve impulses

The information the is picked up by the sensors goes to the brain through the ___________ pathway. a) efferent b) afferent c) interpretation d) interconnected

b) afferent

The door slams shut loudly and you flinch. After a few seconds, you realize that your heart is beating very rapidly and forcefully. This response is the result of your __________ nervous system. a) afferent b) autonomic c) central d) somatic

b) autonomic

Irritability means the neuron a) can contract. b) can respond to stimuli. c) gets annoyed. d) is sensitive.

b) can respond to stimuli.

The basis for differentiation between gray matter and white matter in the CNS is the presence of __________ in white matter. a) unmyelinated fibers b) myelinated fibers c) Schwann cells d) ependymal cells

b) myelinated fibers

Bodily functions that follow "a law unto itself" are controlled by the involuntary nervous system. This system is also termed __________ and functions to __________. a) the afferent nervous system (ANS); convey impulses to the CNS from sensory receptors located throughout the body b) the autonomic nervous system (ANS); conduct impulses from the CNS to cardiac muscle, smooth muscle, and glands c) the motor efferent division; conduct impulses from the CNS to effectors (muscles and glands) d) visceral sensory fibers; transmit impulses from the visceral organs (organs within the ventral body cavity) e) the somatic nervous system; conduct impulses from the CNS to skeletal muscles

b) the autonomic nervous system (ANS); conduct impulses from the CNS to cardiac muscle, smooth muscle, and glands

During the relative refractory period:

both b and c apply.

In axonal transport, anterograde movement is transport away from the cell body. Which of the following move in this direction? a) Worn out organelles b) Vesicles containing signal molecules that activate genes c) Mitochondria and enzymes needed to synthesize certain neurotransmitters d) Messages from the synapse on the condition of axon terminals

c) Mitochondria and enzymes needed to synthesize certain neurotransmitters

The nervous system has three overlapping functions. Which of the following represents a logical sequence (what order they should be in) of these three functions? a) Sensory input, motor output, integration b) Motor output, integration, sensory input c) Sensory input, integration, motor output d) Integration, sensory input, motor output

c) Sensory input, integration, motor output

Which of the following divisions of the nervous system is also known as the involuntary nervous system? a) The somatic nervous system b) The central nervous system c) The autonomic nervous system d) The peripheral nervous system e) The spinal division of the nervous system

c) The autonomic nervous system

In the figure above, C most specifically represents which subdivision of the nervous system? a) The parasympathetic nervous system b) The sensory (afferent) division c) The somatic nervous system d) The sympathetic nervous system e) The autonomic nervous system

c) The somatic nervous system

When considering the relationship between a structural classification and a functional classification of neurons, it can be said that __________. a) all multipolar neurons are interneurons b) all motor neurons are unipolar neurons c) all bipolar neurons are sensory neurons d) unipolar neurons only function as motor neurons

c) all bipolar neurons are sensory neurons

The portion of an axon that communicates with its target cell is the __________. a) dendrite b) axon hillock c) axon terminal d) cell body

c) axon terminal

Match the system with its correct description: The peripheral nervous system __________. a) only conducts impulses from the CNS to internal organ muscles b) consists of the brain and spinal cord c) consists of cranial and spinal nerves carrying impulses to and from the brain and spinal cord d) only conducts impulses from the CNS to skeletal muscles

c) consists of cranial and spinal nerves carrying impulses to and from the brain and spinal cord

Nerve cell a) microglia b) astrocyte c) neuron ) all of these

c) neuron

What cells form the myelin sheath in the central nervous system? a) astrocytes b) microglia c) oligodendrocytes d) ependymal cells

c) oligodendrocytes

Visceral sensory (afferent) fibers carry information from the _______. a) CNS to skeletal muscles b) skin, skeletal muscles, and joints to the CNS c) organs in the ventral body cavity to the CNS d) CNS to smooth muscles, cardiac muscles, and glands

c) organs in the ventral body cavity to the CNS

The somatic sensory (afferent) fibers of the peripheral nervous system transmit information from the __________ to the CNS. a) kidney b) heart c) skin d) stomach e) sweat glands

c) skin

In the figure shown, A represents a neuron carrying information from the eye to the brain. Which of the following correctly describes A? a) Motor nerve fiber within a cranial nerve b) Motor nerve fiber within a spinal nerve c) Sensory nerve fiber within a spinal nerve d) Sensory nerve fiber within a cranial nerve

d) Sensory nerve fiber within a cranial nerve

What is the primary difference between the somatic nervous system and the autonomic nervous system? a) The autonomic nervous system enables us to control our involuntary muscles, while the somatic nervous system controls our glands. b) The somatic nervous system enables us to control our involuntary muscles, while the autonomic nervous system controls our glands. c) The autonomic nervous system allows us to consciously control our skeletal muscles, and the somatic nervous system controls activities that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract. d) The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activities that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

d) The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activities that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

In axonal transport, retrograde movement is transport toward the cell body. Which of the following move in this direction? a) Mitochondria b) Membrane components used to renew the axon plasma membrane c) Cytoskeletal elements d) Worn out organelles e) Enzymes needed to synthesize certain neurotransmitters

d) Worn out organelles

A neuron with a distal peripheral process and a central process that extends to the CNS is most likely _________________. a) an association neuron b) a motor neuron c) an interneuron d) a sensory neuron

d) a sensory neuron

Match the system with its correct description: The somatic nervous system __________. a) consists of cranial and spinal nerves carrying impulses to and from the brain and spinal cord b) conducts impulses from the CNS to visceral organ muscles c) consists of the brain and spinal cord d) conducts impulses from the CNS to the skeletal muscles

d) conducts impulses from the CNS to the skeletal muscles

Each neuron in our bodies has a life span of __________. a) 120 days b) 10 years c) 10 months d) our life span

d) our life span

Organelles for degradation or recycling are moved through the axon by __________. a) saltatory movement b) anterograde movement c) nodal movement d) retrograde movement

d) retrograde movement

Somatic sensory (afferent) fibers carry information from the _______. a) CNS to skeletal muscles b) organs in the ventral body cavity to the CNS c) CNS to smooth muscles, cardiac muscles, and glands d) skin, skeletal muscles, and joints to the CNS

d) skin, skeletal muscles, and joints to the CNS

While studying for an exam, you reach for a beverage. To extend your arm, your __________ nervous system is activated. a) afferent b) autonomic c) sympathetic d) somatic

d) somatic

Bodily functions that follow "a law unto itself" are controlled by the involuntary nervous system. This system is also termed __________ and functions to __________. a) the afferent nervous system (ANS); convey impulses to the CNS from sensory receptors located throughout the body b) the somatic nervous system; conduct impulses from the CNS to skeletal muscles c) the motor efferent division; conduct impulses from the CNS to effectors (muscles and glands) d) the autonomic nervous system (ANS); conduct impulses from the CNS to cardiac muscle, smooth muscle, and glands e) visceral sensory fibers; transmit impulses from the visceral organs (organs within the ventral body cavity)

d) the autonomic nervous system (ANS); conduct impulses from the CNS to cardiac muscle, smooth muscle, and glands

The influx of positive charges makes the membrane potential more positive and is known as:

depolarization

The point marked 2, on the figure, can be described as ________.

depolarizing graded potential as ions move through nonvoltage-gated channels

Movement of ions or other substances from a higher concentration to a lower concentration is called

diffusion.

Which of the following neuroglia is most responsible for helping determine capillary permeability in nervous tissue? a) Microglial cells b) Ependymal cells c) Schwann cells d) Oligodendrocytes e) Astrocytes

e) Astrocytes

Which of the following neuroglia line the central cavities of the brain and spinal cord and provide a fairly permeable barrier between the CSF and nervous tissue? a) Schwann cells b) Oligodendrocytes c) Microglial cells d) Astrocytes e) Ependymal cells

e) Ependymal cells

Neurons can be classified structurally by the number of processes extending from their cell bodies. Which of the following is the most common neuron type in humans? a) Pseudounipolar b) Unipolar c) Bipolar d) Multipolar and bipolar neurons are present in equal proportions e) Multipolar

e) Multipolar

The chromatophilic substance, or Nissl bodies, seen in the neuron cell body represents which cellular organelle(s)? a) Microtubules b) Nucleus c) Mitochondria d) Centrioles e) Rough endoplasmic reticulum

e) Rough endoplasmic reticulum

The voluntary nervous system is to the involuntary nervous system as ________. a) the motor system is to the sensory system b) the peripheral nervous system is to the central nervous system c) the efferent system is to the afferent system d) cranial nerves are to spinal nerves e) the somatic nervous system is to the autonomic nervous system

e) the somatic nervous system is to the autonomic nervous system

A series of measurements with a voltmeter show a neuron's membrane potential becoming more negative, from -70 mV to -85 mV. This neuron is experiencing a:

hyperpolarization phase.

Sodium ion concentration in the cytoplasm of a neuron __________ when its voltage-gated sodium channels open.

increases

Graded potentials:

may cause either depolarization or hyperpolarization.

Stronger stimuli are interpreted when the CNS receives __________ action potentials.

more frequent

The point marked 5, on the figure, can be described as ________.

the period of increased K+ permeability that typically lasts longer than needed to restore the resting state

The point at which the all-or-none principle of action potential generation is reached is termed the __________.

threshold

Resting membrane potential is restored by the sodium-potassium ion pump, or Na+/K+ ATPase, which moves

two potassium ions into the cell and three sodium ions out of the cell.