A&P Ch. 12/13 Review

Bipolar neurons are commonly ________.

found in the retina of the eye

A neuron that conducts impulses away from the point of stimulus and toward the CNS is called a(n)

sensory neuron

A neuron that conducts impulses toward the CNS is called a(n)

sensory neuron

Visceral reflexes result in the contraction of ___________ muscles, while somatic reflexes involve _____________ muscle contraction.

smooth/cardiac, skeletal

If the caudal portion of the neural tube failed to develop properly the ________.

spinal cord may be affected

Cell bodies of the sensory neurons of the spinal nerves are located in ________.

the dorsal root ganglia of the spinal cord

The release of neurotransmitters at the synapse requires

the influx of calcium

A second nerve impulse cannot be generated until ________.

the membrane potential has been reestablished

Saltatory conduction is made possible by

the myelin shealth

The integrative functions of the nervous system are performed mainly by

interneurons

The neural cells responsible for the analysis of sensory inputs and coordination of motor outputs are

interneurons

Somatic reflexes share what characteristics?

They're quick They're monosynaptic They're stereotyped They require stimulation

Which of the following is not true of neurons? a. They respond to physical and chemical stimuli. b. They are the most abundant cells of nervous tissue. c. They conduct nerve impulses. d. They release chemical regulators called neurotransmitters. e. All of the above are true.

c. They conduct nerve impulses

Phagocytic cells of the CNS

microglia

The glial cells that fight infection in the CNS are

microglia

Stepping on a tack may initiate a

crossed extensor reflex

An example of an ipsilateral reflex would be

flexor, knee-jerk, stretch, withdrawal

The spinal cord extends from the ____________ to the ______________ region of the vertebral column.

foramen magnum, lumbar region

Hyperpolarization of the neuron plasma membrane will shift the membrane potential toward

-90mV

Depolarization of the neuron plasma membrane will shift the membrane potential toward

0mV

The adult spinal cord extends only to the

1st or 2nd lumbar vertebrae

Inhibition of acetylcholinesterase by poisoning will block neurotransmission at the neuromuscular junction because

ACh is blocked from attacing to the postsynaptic ACh receptors

The gray matter in the brain resembles the letter

H

Surround neuron cell bodies in ganglia of PNS

Schwann cells

Which of the following is incorrect concerning a nerve impulse? a. It travels in only one direction. b. It is an all-or-none response. c. It is a series of depolarizations followed by repolarizations. d. It is initiated at the axonal hillock. e. All of the above are correct.

a. It travels in only one direction

Which of the following is incorrect concerning a nerve impulse? a. It travels in only one direction. b. It is an all-or-none response. c. It is a series of repolarizations followed by depolarizations. d. It is initiated at the axonal hillock. e. All of the above are correct.

a. It travels in only one direction.

Which of the choices below describes the autonomic nervous system (ANS)? a. motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands b. motor fibers that conduct nerve impulses from the CNS to skeletal muscles c. 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 d. sensory and motor neurons that supply the digestive tract e. all of these

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

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________.

absolute refractory period

Time when the neuron cannot respond to a second stimulus, no matter how strong

absolute refractory period

Also called a nerve impulse transmitted by axons

action potential

Sensory neurons are also referred to as ______ neurons while motor neurons are called ________ neurons.

afferent, efferent

The structure of the spinal cord can be described as 1. composed of 31 segments 2. having a cervical enlargement, lumbar enlargement, and tapering toward the sacral region 3. a central core of white matter surrounded by gray matter 4. having gray matter composed of neuron cell bodies and unmyelinated nerve fibers

all of these

A neuron that has as its primary function the job of connecting other neurons is called a(n) ____.

association neuron

Form tight seal called the blood brain barrier

astrocytes

Most abundant and versatile glial cells of CNS

astrocytes

What cells line the ventricles of the brain?

astrocytes

The part of a neuron that conducts impulses away from its cell body is called a(n) ________.

axon

Once initiated at the axon hillock, the action potential moves in the order:

axon -> synapse -> dendrite

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

b. Ions always move passively across membranes.

Which of the following describes the nervous system integrative function? a. senses changes in the environment b. analyzes sensory information, stores information, makes decisions c. responds to stimuli by gland secretion or muscle contraction d. takes place in the body's periphery e. none of these

b. analyzes sensory information, stores information, makes decisions

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

b. anchor neurons to blood vessels

For an action potential to begin, an area of excitable membrane must

be depolarized to threshold level

Striking the "funny bone" (ulnar nerve) may cause injury to a nerve of this plexus.

brachial plexus

Trauma to a nerve of this plexus may cause wrist drop.

brachial plexus

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

c. acetylcholine

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

c. they are mitotic

Ascending tracts of the spinal cord

carry sensory information to the brain

Below L2, the vertebral canal is occupied by a bundle of spinal nerve roots called

cauda equina

The soma of a mature neuron lacks

centrioles

The subarachnoid space contains

cerebrospinal fluid

The phrenic nerve branches from this plexus.

cervical plexus

The sciatic nerve is a combination of which two nerves?

common fibular and tibial

Spinal nerves are called mixed nerves because they

contain sensory and motor fibers

Chemical synapses are characterized by all of the following except: a. the release of neurotransmitter by the presynaptic axonal membranes b. the postsynaptic neuronal membranes bear receptors that bind neurotransmitter c. fluid fills the gap separating the neurons d. ions flow through protein channels from the presynaptic to the postsynaptic neuron e. all of these are characteristic of chemical synapses

d. ions flow through protein channels from the presynaptic to the postsynaptic neuron

Which of the following is not a way that sensory receptors are classified? a. type of stimulus detected b. location in the body c. structural complexity d. sensitivity to a stimulus e. all of these

d. sensitivity to a stimulus

The cytoplasmic extensions that, with the cell body, provide the main receptive surfaces for neurons are

dendrites

When the inside of the cell membrane of a neuron becomes less negative (moves toward zero) as a result of stimulation, the condition is called

depolarization

___ happens when the interior of the cell becomes less negative due to an influx of sodium ions

depolarization

What is the role of acetylcholinesterase?

destroy ACh a brief period after its release by the axon endings

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

e. All of the above are correct

Which of the following is not a chemical class of neurotransmitters? a. acetycholine b. amino acid c. biogenic amines d. ATP and other purines e. all of these are correct

e. all of these are correct

Which of the following is not an example of a neurotransmitter? a. dopamine b. acetylcholine c. carbon monoxide d. serotonin e. all of these are neurotransmitters

e. all of these are neurotransmitters

The brachial plexus gives rise to all of the following nerves except a. the axillary nerve b. the median nerve c. the radial nerve d. the ulnar e. all of these come from the brachial plexus

e. all of these come from the brachial plexus

. The following are the steps involved in a reflex arc 1. activation of a sensory neuron 2. activation of a motor neuron 3. response by an effector 4. arrival of a stimulus and activation of a receptor 5. information processing The proper sequence of these steps is a. 1, 3, 4, 5, 2 b. 4, 5, 3, 1, 2 c. 4, 2, 5, 1, 3 d. 4, 3, 1, 5, 2 e. none of these

e. none of these

What is the correct sequence of the following events in the generation of a nerve impulse? 1. The membrane becomes repolarized. 2. Sodium channels open and sodium ions diffuse inward. 3. The membrane becomes depolarized 4. Potassium channels open and potassium ions diffuse outward. a. 3,2,4,1 b. 2,1,4,3 c. 1,2,4,3 d. 4,1,3,2 e. none of these

e. none of these

Line the internal cavities of brain and spinal cord

ependymal cells

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?

ependymal cells

To perform their roles, neurons must have the properties of

excitability, secretion, and conductivity

In a crossed-extensor reflex, if the right arm was grabbed it would flex and the left arm would ________.

extend

In which portion of the spinal cord do interneurons lie?

gray matter

An inhibitory postsynaptic potential (IPSP) is associated with ____.

hyperpolarization

Depolarization of an axon during generation of an action potential is produced by

inward diffusion of Na+

Reflex arcs in which the sensory stimulus and the motor response occur on the same side of the body are

ipsilateral

The knee-jerk reflex is a

ipsilateral, monosynaptic, stretch reflex

Saltatory conduction

is faster than conduction on an unmyelinated fiber

A fall or improper administration of an injection to the buttocks may injure a nerve of this plexus.

lumbar plexus

Action potentials travel fastest in axons that are ____ and ____.

myelinated, large in diameter

In what way does the interior surface of a cell membrane of a resting (non-conducting) neuron differ from the external environment? The interior is ________.

negatively charged and contains less sodium

Functional/structural unit of nervous system

neuron

Myelinates nerve fibers in the CNS

oligodendrocytes

Schwann cells are functionally similar to ___.

oligodendrocytes

The obturator and femoral nerves branch from this plexus.

sacral plexus

Repolarization of an axon during the generation of an action potential is produced by

outward diffusion of K+

An individual accidentally transected the spinal cord between T1 and L1. This would result in ________.

paraplegia

A withdrawal reflex, or flexor reflex, consists of

polysynaptic reflex arc

Myelinates nerve fibers in the PNS

schwann cells

Immediately after an action potential has peaked, which cellular gates open?

potassium

An exceptionally strong stimulus can trigger a response

relative refractory period

The specific period during which potassium ions diffuse out of the neuron due to a change in membrane permeability

repolarization

Starting at the spinal cord, the subdivisions of the brachial plexus are (in order):

roots, trunks, divisions, and cords

Spinal nerves exiting the cord from the level of L4 to S4 form the ________.

sacral plexus

The patellar ʺknee jerkʺ reflex is an example of a(n) ________.

stretch reflex

An impulse from one nerve cell is communicated to another nerve cell via the ________.

synapse

Neurotransmitters are released from synaptic vesicles located within

synapses

Striking the "funny bone" is actually stimulation of (or injury to) the ________.

ulnar nerve

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

voltage-gated channel