A&P Chapter 11

There are ___ pairs of cranial nerves and ___ pairs of spinal nerves

12; 31

Arrange the events of synaptic transmission in correct sequence

5, 3, 2, 4, 1

The nervous system

All choices are correct

The speed of an action potential depends upon

All of the choices are correct

. Which of the following statements regarding voltage-gated K+ channels is true?

All of these statements are true.

Each voltage-gated Na+ ion channel has two voltage sensitive gates: an activation gate and an inactivation gate. Which of the following would occur during depolarization?

Both activation and inactivation gates are open

Check all that apply: Identify the mechanisms by which neuromodulators alter synaptic transmission.

Changing neurotransmitter receptor numbers; Affecting breakdown of neurotransmitters; Affecting the removal of neurotransmitters

Match the neuroglial cell with its function: Schwann cell

E. form myelin sheath around part of the axon in the PNS

Match the following concerning concentration differences across the plasma membrane: potassium ions

E. plasma membrane is more permeable to this ion because of leak ion channels

Match the term with the correct definition: repolarization

E. return to the resting membrane potential

Gray matter consists of bundles of myelinated axons

FALSE

. A person who has seizures might have a deficit of which of the following?

GABA

Identify the statement that best differentiates gray matter and white matter.

Gray matter consists of cell bodies and dendrites whereas white matter consists mostly of myelinated axons

Match the neuronal pathways and circuits with the correct definition: Oscillating (reverberating) circuit

Important in functions that are periodically active such as the sleep/wake cycle and respiration.

In hyperpolarization

K+ ions tend to diffuse out of the cell

Which of the following statements regarding neuroglia is false?

Neuroglia produce action potentials for skeletal muscles

Identify structure "E" on the neuron

Node of Ranvier (farthest to the right)

Match the neuronal pathways and circuits with the correct definition: Convergent pathway

Pathways that allow different parts of the nervous system to affect the activity of a neuron

Match the neuronal pathways and circuits with the correct definition: Divergent pathway

Pathways that allow one part of the nervous system to affect more than one part of the nervous system.

Identify the correct sequence of information in a chemical synapse.

Presynaptic terminal; synaptic cleft; postsynaptic membrane

Why isn't an action potential transmitted from a postsynaptic membrane to a presynaptic terminal?

Presynaptic terminals have no acetylcholine receptors

Identify structure "D" on the neuron

Schwann cell (2nd from the right)

Schwann cells differ from oligodendrocytes in which of the following ways?

Schwann cells form a myelin sheath around a portion of only one axon, while oligodendrocytes can surround portions of several axons

Gray matter has little myelination, whereas white matter has abundant myelination

TRUE

True or False: The nervous system and the endocrine system are the major control systems of the body.

TRUE

If five action potentials arrive at the same synapse in very close succession, which of the following would occur?

Temporal summation occurs.

Action potentials at a chemical synapse

travel from presynaptic terminal to presynaptic membrane

Axons contain

trigger zone

Neurons that have a single axon and a single dendrite are

bipolar

A local anesthetic such as Novocaine decreases membrane permeability to Na+ ions. The use of this anesthetic will

block sensory input into the CNS

The strength of a stimulus is communicated through

both the frequency and the length of time action potentials are produced.

The function of acetylcholinesterase is to

breakdown acetylcholine in the synapse

White matter is composed of

bundles of myelinated axons

What ion is necessary for the release of neurotransmitter from synaptic vesicles?

calcium

Voltage-gated sodium channels are sensitive to changes in the extracellular concentration of

calcium ions.

Neurotransmitters

cause the production of action potentials in the postsynaptic membrane.

Which of the following is NOT true of reactive astrocytosis

causes the spread of inflammation

Protein synthesis in neurons occurs in

cell bodies or soma

The absolute refractory period assures

completion of repolarization before another action potential

autonomic nervous system

has two sets of neurons in a series

Check all that apply: Identify the functions of the nervous system.

controlling muscles and glands; integrating information; receiving sensory input

When two or more presynaptic neurons synapse with a single postsynaptic neuron in the CNS, a(n) _______ pathway is formed.

convergent

Axons

have a distal portion that branches to form the presynaptic terminals.

____________ are processes that conduct electric signals toward the cell body.

dendrites

Identify structure "A" on the neuron

dendrites (farthest to the left)

The figure illustrates the Action Potential. What does "B" represent?

depolarization

Check all that apply: Identify the phases of an action potential.

depolarization; hyperpolarization; repolarization

Receptor molecules

determine whether a neurotransmitter will be excitatory or inhibitory

The enteric nervous system consists of plexuses within the walls of the

digestive tract

Sensory neurons carrying action potentials from pain receptors synapse within the spinal cord with interneurons. These interneurons synapse with motor neurons leading back to an effector and ascending neurons that carry action potentials toward the brain. This is an example of a(n) _____ pathway.

divergent

An inhibitory postsynaptic potential (IPSP) can result from the

either influx of chloride or outflow of potassium ions.

Gap junctions are functional __________ synapses

electrical

Synapses in which gap junctions allow ions to diffuse quickly from cell to cell are called ______ synapses.

electrical

Monamine oxidase inhibitors (MAO inhibitors)

enhance the binding of norepinephrine to its receptors

Cerebrospinal fluid is produced by ____________ cells

ependymal

Hydrocephaly is a condition whereby cerebrospinal fluid accumulates around the brain. What supportive cells continue CSF production despite it backing up in the subarachnoid space?

ependymal cells

When a neuron releases a neuromodulator that _____ the release of neurotransmitters from another neuron, this is called presynaptic facilitation.

facilitation

A neuron is receiving a stimulus which gets stronger and stronger. The result is

frequency of occurrence of action potentials increases

Action potentials are conducted more rapidly when transmission is

from node to node on a myelinated axon

Cell bodies of the peripheral nervous system are located in

ganglia

Groups of related nerve cell bodies located outside of the central nervous system are called _____.

ganglia

____________ are collections of neuron cell bodies located outside of the central nervous system.

ganglia

What inhibitory neurotransmitter is blocked in strychnine poisoning?

glycine

Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability of potassium. You would expect his cells to

hyperpolarize

An IPSP is inhibitory because it

hyperpolarizes the postsynaptic membrane.

The absolute refractory period ends when

inactivation gates of voltage-gated Na+ ion channels reopen.

When a neuron releases a neuromodulator that _____ the release of neurotransmitters from another neuron, this is called presynaptic facilitation.

increases

A local potential

increases or decreases in direct proportion to the stimulus strength.

Local hyperpolarization in a synapse is called a(an)

inhibitory postsynaptic potential

Damage to a postsynaptic membrane would

interfere with the ability to respond to neurotransmitter.

A neuron within the central nervous system that carries action potentials from one neuron from to another is called a/an

interneuron

A neuromodulator

is a substance released from neurons that influences the sensitivity of neurons to neurotransmitters

The opening of more and more Na+ ion channels during depolarization

is an example of a positive feedback cycle.

. During the absolute refractory period, the cell

is insensitive to further stimulation

The central nervous system

is the site for processing information

For the resting membrane potential, increasing the sodium ion concentration in the ECF results in

little change in the membrane potential

. A change in resting membrane potential confined to a small area is called a(n)

local potential

The figure illustrates the Action Potential. What does "A" represent

local potential

Worksheet Questions:

The division of the nervous system that transmits electrical impulses towards cardiac muscle, smooth muscle and glands is the autonomic nervous system; while the division of the nervous system that transmits electrical impulses towards skeletal muscle is the somatic nervous system.

Worksheet Questions

The division of the peripheral nervous system that transmits electrical impulses from sensory receptors to the CNS is the afferent division, while the afferent division of the peripheral nervous system transmits electrical impulses from the CNS toward muscles and glands.

. Rapid removal or destruction of neurotransmitter in the synaptic cleft

may affect the ability of the postsynaptic membrane to generate action potentials

____________ are neuroglia cells that are macrophages

microglia

The same neurotransmitter binds to a postsynaptic cell but produces a variety of different effects. What does this mean?

The postsynaptic cell is expressing different types of receptors for the same neurotransmitter.

Which of the following is true?

The resting membrane potential is proportional to the tendency for K+ to diffuse out of the cell

If you cut bundles of axons and their myelin sheaths in the PNS, you cut

nerves

Compounds classified as ______ alter synaptic transmission by changing neurotransmitter receptor numbers or affecting the breakdown and/or removal of neurotransmitter.

neuromodulators

Identify structure "B" on the neuron

neuron cell body (soma)(2nd from the left)

Viagra is used to treat erectile dysfunction by prolonging the effects of _____ on blood vessels.

nitric oxide (NO)

Gaps or interruptions in the myelin sheath are called

nodes of Ranvier

Clusters of gray matter deep within the brain are called

nuclei

Neurons arranged in a circular pathway form

reverberating circuits

Action potentials are conducted rapidly from one node of Ranvier to the next in a process called ____________ conduction

saltatory

The nervous system has two subdivisions - the central nervous system and the ____________ nervous system.

peripheral

The figure is a process figure of the chemical synapse. What does "E" represent?

postsynaptic membrane

Low levels of ___ can have dire consequences on the functioning of neurons because of its role in membrane repolarization

potassium ions

Neurotransmitters are released from the

presynaptic terminal

The figure is a process figure of the chemical synapse. What does "C" represent?

presynaptic terminal

Synaptic vesicles contain neurotransmitters and are present in the

presynaptic terminals

The blood-brain barrier

protects neurons from toxic substances in the blood.

Neurons in the skin that are responsible for detecting pain are

pseudo-unipolar

A decrease in the number of voltage-gated Ca2+ ion channels in the presynaptic terminal would

reduce or inhibit transmission across the synapse

Check all that apply: Identify the characteristics of action potentials.

The strength of the stimulus determines the frequency of the action potentials; They are all-or-none; They are propagated in a non-decremental fashion.

The figure illustrates the Action Potential. What does "C" represent?

repolarization

What type of neuroglial cells provide support and nutrition to sensory ganglia in the PNS?

satellite cells

Which of the following is NOT a neuroglia of the CNS

satellite cells

Most unipolar neurons are ____________ neurons

sensory

Saltatory conduction of an action potential means that

an action potential is conducted from one node of Ranvier to the next node.

A stimulus either causes an action potential or it doesn't. This is called

an all-or-none response

. When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to sodium ions,

an excitatory postsynaptic potential (EPSP) will result

Which of the following will lead to depolarization

an increase in K+ ions in the extracellular fluid

Dendrites

are the input part of the neuron

Nissl bodies are

areas of rough endoplasmic reticulum.

LouAnn is being treated for a neurological condition with a specific drug that target neurons deep within the brain. Which glial cell must be bypassed by this drug in order for it to be effective?

astrocyte

Identify structure "C" on the neuron.

axon (middle)

Nerve fibers are also called ____________.

axons

A change in the resting membrane potential has the following characteristics (non-propagated, graded, can summate). This type of change can

be a local potential and a consequence of an increase in the permeability of Na+

Which of the following is mismatched?

somatic nervous system - sensory division of PNS

The junction of a neuron with another cell is a/an

synapse

The figure is a process figure of the chemical synapse. What does "D" represent?

synaptic cleft

The figure is a process figure of the chemical synapse. What does "B" represent?

synaptic vesicle

The figure is a process figure of the chemical synapse. What does "A" represent?

voltage-gated calcium channel

In some cells, an afterpotential occurs because

there is prolonged, elevated permeability to potassium during repolarization

Which of the following is NOT true about astrocytes

they can aid in the regeneration of injured neurons

In order for local potentials to trigger an action potential, the membrane must reach a level called the ______.

threshold

The figure illustrates the Action Potential. What does "D" represent?

threshold

The motor (efferent) division of the peripheral nervous system

transmits impulses from the CNS to skeletal muscle

Receptor molecules in synapses

. have a high degree of specificity

In an EPSP (excitatory postsynaptic potential), there is a

. local depolarization

Which of the following statements accurately describes events that occur as a result of a local potential reaching threshold

A positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open

Match the term with the correct definition: Local Potential

A. a small change in the resting membrane potential confined to a small area

Match the following concerning concentration differences across the plasma membrane: higher inside cell

A. concentration of potassium

Match the neuroglial cell with its function: astrocytes

A. influence function of blood-brain barrier

Which of the following is mismatched

A. microglia - provide support for the neuron cell body

. Neurotransmitter is being released at a synapse. Which of the following occurs last?

An action potential is produced in the postsynaptic membrane.

Which of the following events is NOT a characteristic of an action potential

As sodium ions enter, the inside of the plasma membrane becomes more negative.

Match the term with the correct definition: Resting Membrane Potential

B. a charge difference across the plasma membrane when the cell is in an unstimulated state

Match the following concerning concentration differences across the plasma membrane: higher outside cell

B. concentration of sodium and chloride

Match the neuroglial cell with its function: microglia

B. macrophages in CNS

Match the term with the correct definition: Action Potential

C. a larger change in resting membrane potential that spreads over entire surface of a cell

Match the following concerning concentration differences across the plasma membrane: large molecules trapped inside cell

C. negatively charged proteins

Match the neuroglial cell with its function: ependymal cells

C. produce cerebrospinal fluid

Match the neuroglial cell with its function: oligodendrocyte

D. form myelin sheath around axons in CNS

Match the term with the correct definition: depolarization

D. membrane becomes more positive when sodium ions diffuse into cell

Match the following concerning concentration differences across the plasma membrane: requires ATP

D. sodium/potassium pump

Which of the following situations occurs in electrically excitable cells?

Depolarization causes voltage-gated sodium ion channels to open.

Which of the following is true?

Unmyelinated axons rest in invaginations of Schwann cells or oligodendrocytes

If the ECF around a nerve cell is replaced with an isotonic saline solution that contains potassium ions and other solutes at concentrations very close to the ECF concentrations of a normal cell, the result is

a resting membrane potential close to its normal value.

What is the only neurotransmitter released at the neuromuscular junction?

acetylcholine

The figure illustrates the Action Potential. What does "E" represent?

afterpotential

Which of the following is responsible for problem-solving skills?

central nervous system

Identify the type of synapse that includes a presynaptic cell, synaptic cleft, and postsynaptic cell.

chemical

The respiratory center of the brain (taking into account input from chemoreceptors, pulmonary stretch receptors and higher centers of the brain to determine respiratory output) is an example of a ______ circuit.

converging

The sensory (afferent) division of the peripheral nervous system

conveys action potentials to the CNS

The gray matter of the cerebrum is composed of neuron cell bodies and makes up both the ______ and the ______.

cortex ; deep cerebral nuclei

The peripheral nervous system includes

cranial nerves

Enkephalins produce presynaptic inhibition in neurons transmitting pain signals. Increased levels of enkephalins will

decrease awareness of pain

Fran has a microbial infection attacking his brain. Which cell type would you expect to proliferate and be most active during this time?

microglial cells

Check All That Apply: Identify the two functional sub-divisions of the peripheral nervous system

motor division; sensory division

A neuron with several dendrites and a single axon would be called a ____________ neuron.

multipolar

The motor neurons responsible for making a fist are

multipolar

An action potential

occurs when the local potential reaches threshold level

Multiple sclerosis is a neurological disorder in which myelin sheaths in the CNS are destroyed. Which of the following neuroglial cells is being damaged in multiple sclerosis?

oligodendrocyte

Continuous conduction of an action potential means that

one action potential stimulates the production of a new action potential at the adjacent site

When repolarization of a neuron is complete, the

original polarity of the neuron is restored

Which type of circuit is associated with complex neuronal processes, such as solving mathematical equations?

parallel after-discharge

Digestion of food is regulated by the

parasympathetic division of the ANS

A neuron that conducts pain sensations to the central nervous system would be classified as a/an

sensory or afferent neuron

Depolarization of the nerve cell membrane occurs when there is a rapid influx (inflow) of

sodium ions

. During depolarization of the plasma membrane

sodium ions move rapidly into the cell.

When two action potentials arrive simultaneously at two different presynaptic terminals that synapse with the same postsynaptic neuron

spatial summation occurs.

The central nervous system includes the

spinal chord

The junction between two neurons is a

synapse

Gray matter on the surface of the brain is called

the cortex

If the charge difference across the plasma membrane is decreased

the membrane potential is more positive

A series of local potentials causes the membrane potential to move to -80 mV. Predict the result.

the neuron is hyperpolarized

Suppose both excitatory and inhibitory neurons synapse with a single postsynaptic neuron. What determines if an action potential is initiated in the postsynaptic neuron

the number of EPSPs in relation to the number of IPSPs

Chemical synapses are characterized by

the release of neurotransmitter by the presynaptic terminal.

The plasma membrane of a neuron is more permeable to potassium ions because

there are more leak ion channels for K+ than NA+

Nervous tissue of the CNS that is composed primarily of myelinated axons is often referred to as ______ matter.

white