A&P Nervous Tissue Flashcards

1
Q

The subdivisions of the PNS are the ___, ___ and ___.

A

Autonomic, somatic, enteric.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The two divisions of the autonomic nervous system are the ___ and the ___ division.

A

Sympathetic and parasympathetic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T/F: At a chemical synapse between two neurons, the neuron receiving the signal is called the presynaptic neuron, and the neuron sending the signal is called the postsynaptic neuron.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T/F: Neurons in the PNS are always capable of repair while those in the CNS are not

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following statements are true?

(1) The sensory function of the nervous system involves sensory receptors sensing certain changes in the internal and external environments.
(2) Sensory neurons receive electrical signals from sensory receptors.
(3) The integrative function of the nervous system involves analyzing sensory information, storing some of it, and making decisions regarding appropriate responses.
(4) Interneurons are located primarily in the PNS.
(5) Motor function involves the activation of effectors (muscles and glands).

A

1, 2, 3 and 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A neuron’s resting membrane potential is established and maintained by

(1) a high concentration of K+ in the extracellular fluid and a high concentration of Na+ in the cytosol,
(2) the plasma membrane’s higher permeability to Na+ because of the presence of numerous Na+ leakage channels,
(3) differences in both ion concentrations and electrical gradients,
(4) the fact that there are numerous large, nondiffusible anions in the cytosol,
(5) sodium–potassium pumps that help to maintain the proper distribution of sodium and potassium.

A

3, 4, and 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Place the following events in a chemical synapse in the correct order:

(1) release of neurotransmitters into the synaptic cleft,
(2) arrival of nerve impulse at the presynaptic neuron’s synaptic end bulb (or varicosity),
(3) either depolarization or hyperpolarization of postsynaptic membrane,
(4) inward flow of Ca2+ through activated voltage-gated Ca2+ channels in the synaptic end bulb membrane,
(5) exocytosis of synaptic vesicles,
(6) opening of ligand-gated channels on the postsynaptic plasma membrane,
(7) binding of neurotransmitters to receptors in the postsynaptic neuron’s plasma membrane

A

2, 4, 5, 1, 7, 6, 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Several neurons in the brain sending impulses to a single motor neuron that terminates at a neuromuscular junction is an example of a circuit.

A

Converging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which of the following statements are true?

(1) If the excitatory effect is greater than the inhibitory effect but less than the threshold of stimulation, the result is a subthreshold EPSP.
(2) If the excitatory effect is greater than the inhibitory effect and reaches or surpasses the threshold level of stimulation, the result is a threshold or suprathreshold EPSP and one or more nerve impulses.
(3) If the inhibitory effect is greater than the excitatory effect, the membrane hyperpolarizes, resulting in inhibition of the postsynaptic neuron and the inability of the neuron to generate a nerve impulse.
(4) The greater the summation of hyperpolarizations, the more likely a nerve impulse will be initiated.

A

1, 2 and 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following statements are true?

(1) The basic types of ion channels are gated, leakage, and electrical.
(2) Ion channels allow for the development of graded potentials and action potentials.
(3) Voltage-gated channels open in response to changes in membrane potential.
(4) Ligand-gated channels open due to the presence of specific chemicals.
(5) A graded potential is useful for communication over long distances.

A

2, 3 and 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which of the following statements are true?

(1) The frequency of impulses and number of activated sensory neurons encode differences in stimuli intensity.
(2) Larger-diameter axons conduct nerve impulses faster than smaller-diameter ones.
(3) Continuous conduction is faster than saltatory conduction.
(4) The presence or absence of a myelin sheath is an important factor that determines the speed of nerve impulse propagation.
(5) Action potentials are localized, but graded potentials are propagated.

A

1, 2 and 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Neurotransmitters are removed from the synaptic cleft by

(1) axonal transport,
(2) diffusion away from the cleft,
(3) neurosecretory cells,
(4) enzymatic breakdown,
(5) cellular uptake.

A

1, 4 and 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Neurons with just one process extending from the cell body; are always sensory neurons.

A

Unipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Small phagocytic neuroglia

A

Microglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Help maintain an appropriate chemical environment for generation of action potentials by neurons; part of the blood-brain barrier

A

Astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Provide myelin sheath for CNS

A

Oligodendrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Contains neuronal cell bodies, dendrites, axon terminals, unmyelinated axons, and neuroglia

A

Gray matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A cluster of cell bodies within the CNS

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Form CSF and assist in its circulation; form blood-cerebrospinal barrier

A

Ependymal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Neurons having several dendrites and one axon; most common neuronal type

A

Multipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

neurons with one main dendrite and one axon; found in the retina of the eye

A

Bipolar neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

provide myelin sheath for PNS axons

A

Schwann cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

support neurons in PNS ganglia

A

Satellite cells

24
Q

a cluster of neuronal cell bodies located outside the brain and spinal cord

A

Ganglion

25
Q

composed primarily of myelinated axons

A

White matter

26
Q

bundles of axons and associated connective tissue and blood vessels in the PNS

A

Nerves

27
Q

extensive neuronal networks that help regulate the digestive system

A

enteric plexuses

28
Q

a sequence of rapidly occurring events that decreases and eventually reverses the membrane
potential and then restores it to the resting state; a nerve impulse

A

action potential

29
Q

a small deviation from the resting membrane potential that makes the membrane either more
or less polarized

A

graded potential

30
Q

period of time when a second action potential can be initiated with a very strong stimulus

A

relative refractory period

31
Q

the minimum level of depolarization required for a nerve impulse to be generated

A

threshold

32
Q

the recovery of the resting membrane potential

A

repolarization

33
Q

a neurotransmitter-caused depolarization of the postsynaptic membrane

A

excitatory postsynaptic potential

34
Q

a neurotransmitter-caused hyperpolarization of the postsynaptic membrane

A

inhibitory postsynaptic potential

35
Q

time during which a neuron cannot produce an action potential even with a very strong stimulus

A

absolute refractory period

36
Q

polarization that is less negative than the resting level

A

depolarizing graded potential

37
Q

results from the buildup of neurotransmitter released simultaneously by several presynaptic
end bulbs

A

spatial summation

38
Q

the hyperpolarization that occurs after the repolarizing phase of an action potential

A

after-hyperpolarizing phase

39
Q

polarization that is more negative than the resting level

A

hyperpolarizing graded potential

40
Q

results from the buildup of neurotransmitter from the rapid, successive release by a single
presynaptic end bulb

A

temporal summation

41
Q

the part of the neuron that contains the nucleus and organelles

A

cell body

42
Q

rough endoplasmic reticulum in neurons; site of protein synthesis

A

nissl bodies

43
Q

store neurotransmitter

A

synaptic vesicles

44
Q

the process that propagates nerve impulses toward another neuron, muscle fiber, or gland cell

A

axon

45
Q

the highly branched receiving or input portions of a neuron

A

dendrites

46
Q

a multilayered lipid and protein covering for axons produced by neuroglia

A

myelin sheath

47
Q

the outer nucleated cytoplasmic layer of the Schwann cell

A

neurolemma

48
Q

first portion of the axon, closest to the axon hillock

A

initial segment

49
Q

site of communication between two neurons or between a neuron and an effector cell

A

synapse

50
Q

form the cytoskeleton of a neuron

A

neurofibrils

51
Q

gaps in the myelin sheath of an axon

A

nodes of Ranvier

52
Q

general term for any neuronal process

A

nerve fiber

53
Q

area where the axon joins the cell body

A

axon hillock

54
Q

area where nerve impulses arise

A

trigger zone

55
Q

the numerous fine processes at the ends of an axon and its collaterals

A

axon terminals

56
Q

interstitial fluid-filled space separating two neurons

A

synaptic cleft