Chapter 12: Nervous System and Nervous Tissue (Quiz)

Question 1

Identify the functions of the nervous system (3).

Answer 1

Sensation - Taking information in from external stimulus, and sending electrical impulses down nervous system.

Response - When nervous system causes a target tissue (muscle or gland) to produce appropriate response, as a consequence of the external stimulus.

Integration - Combining information from external stimulus with higher cognitive functions (ex memory) and determines appropriate response.

Question 2

What is the function of the afferent neurons?

Answer 2

They conduct impulses from the sensory cells to the central nervous system.

Question 3

Name two subdivisions of the autonomic nervous system

Answer 3

1. Sympathetic Nervous System
2. Parasympathetic Nervous System.

Question 4

What are the 4 different types of glial cells in the CNS? (AOME)

Answer 4

1. Astrocyte
2. Oligodendrocyte
3. Microglia
4. Ependymal Cells

Question 5

What are the 2 types of glial cells in the PNS?

Answer 5

1. Schwann Cells
2. Satellite Cells

Question 6

What are some ways that astrocytes support neurons in the CNS?

Answer 6

1. Maintain concentration of chemicals in extracellular space.
2. Remove excess signalling molecules.
3. Reacting to tissue damage.
4. Contributing to blood-brain barrier.

Question 7

What do oligodendrocytes do?

Answer 7

They provides the myelin insulations for axons in tracts.
One oligodendrocyte provides myelin for multiple axon segments.

Question 8

What do microglia do?

Answer 8

They ingest and digest any cells or pathogens that cause diseases.

Question 9

What do ependymal cells do?

Answer 9

They create cerebrospinal fluid (CSF). They have cilia on their apical surfaces to help move CSF throughout the nervous system.

Question 10

What do Satellite Cells do?

Answer 10

They surround the cell bodies of neurons.
- Provide support, performing similar functions in the periphery as astrocytes in the CNS

Question 11

What do Schwann Cells do?

Answer 11

Insulates axons with myelin in the periphery.

Question 12

What is a myelin sheath

Answer 12

It is a lipid rich layer that surrounds an axon in layers, which helps facilitate the speed of electrical signals.

Question 13

Define dentrites

Answer 13

Processes at the end of a neuron, which provide locations foer other neurons to communicate with the cell body.

Question 14

Define Grey Matter.

Answer 14

Regions of the nervous system containing cell bodies of neurons with few or zero myelinated axons.

Question 15

Define White Matter.

Answer 15

Regions of the nervous system containing mostly myelinated axons, making the tissue appear whiter because of the high lipid content of myelin.

Question 16

What is a nucleus?

Answer 16

A localized collection of neuron cell bodies in the CNS.

Question 17

What are ganglion?

Answer 17

A cluster of neuron cell bodies in the PNS.

Question 18

What is the meaning of the term resting potential membrane?

Answer 18

The difference in charge when ions are scattered across the membrane at concentrations (Usually -70mV).

Question 19

What is the role of the sodium-Potassium Pump?

Answer 19

To actively carry out sodium ions out of the cell, and potassium ions into the cell. Powered by ATP.

Question 20

How does a neuron become depolarized?

Answer 20

By the rapid influx of sodium ions through the nerve cell membrane.

Question 21

What is a refractory period?

Answer 21

A time when an action potential is generated, and another action potential can’t be generated.

Question 22

What is a threshold stimulus?

Answer 22

A stimulus that causes the membrane of a neuron to depolarize at -55mV, so an action potential can be generated.

Question 23

What is the advantage of salatory conduction?

Answer 23

It is very fast, and requires less energy expenditure of the Na/K pump.

Question 24

Why does the synaptic conduction of an impulse occur only in one direction?

Answer 24

Because neurotransmitters are released only from presynaptic terminals. Only postsynaptic membranes have appropriate neurotransmitter receptors.

Question 25

Define: Neurotransmitter

Answer 25

A chemical signal that is released from the synaptic end bulb of a neuron to cause a change in the target cell.

Question 26

Which neuroglia produce myelin in the CNS?

Answer 26

Oligodendrocytes.

Question 27

What are the most important factors that determine the speed of impulse propogation?

Answer 27

Fibre diameter and the presence/absence of the myelin sheath.

Question 28

With respect to synaptic facts, what is false?

Answer 28

The nerve impulses travel from postsynaptic to presynaptic.

It is the other way around.

Question 29

what is a blood-brain barrier?

Answer 29

A physiological barrier that keeps substances that circulate in the rest of the body from getting into the CNS, restricting what can cross from circulating blood into the CNS.