Module 5 (Neurons and Supporting Cells)

Question 1

What are the 2 principle cell types in the NS

Answer 1

Neurons (nerve cells) and supporting cells

Question 2

What are neurons

Answer 2

Cells that are excitable and can generate and transmit rapid electrical signals to other neurons

Question 3

Neuron structure

Answer 3

Structural units of the NS
Cell body
Dendrites
Axon

Question 4

Direction of nerve impulses

Answer 4

Unidirectional so they only occur in one direction
Do not travel in the opposite direction

Question 5

Pathway of nerve impulses

Answer 5

From the dendrites to the call body through the axon to reach dendrites of adjacent neurons or target organs

Question 6

3 classifications of neurons

Answer 6

Pseudounipolar (unipolar)
Bipolar
Multipolar

Question 6

Classification of neurons

Answer 6

Can be classified based on the number of cellular processes (dendrites and axons) that extend from the cell body

Question 7

Pseudounipolar (unipolar) neurons

Answer 7

Have one cellular process that splits into a dendrite and an axon

Question 8

What kind of nerves are pseudounipolar (unipolar)

Answer 8

General sensory nerves

Question 9

Bipolar neurons

Answer 9

Have one dendrite and one axon that extend directly from the cell body
Have 2 distinct cellular processes

Question 10

Where are bipolar neurons found

Answer 10

Only in special senses, like sight and hearing

Question 11

Multipolar neruons

Answer 11

Have multiple dendrites and one axon
Summing to 3 or more cellular processes

Question 12

What type of neurons are multipolar

Answer 12

Motor neurons
Most common

Question 13

Supporting cells of the CNS

Answer 13

Known as neuroglia or glia

Question 14

Functions of supporting cells

Answer 14

Protect and support neurons
Aid in sending signals between neurons to improve communication
Do not generate or transmit nerve impulses

Question 15

4 type of supporting cells in the CNS

Answer 15

Astrocytes
Microglia
Ependymal
Oligodendrocytes

Question 16

What are astrocytes

Answer 16

Large star shaped cells with numerous processes
Communicate with neurons and blood vessels to maintain the integrity of the neural tissue

Question 17

Which cell is the most abundant of the glial cells in the CNS

Answer 17

Astrocytes

Question 18

What are microglia

Answer 18

Small glial cells, perform many protective functions in the CNS
Able to phagocytose and eliminate waste products from other cells

Question 19

What is the least common type of supporting cell

Answer 19

Microglia

Question 20

What are ependymal

Answer 20

Cuboidal in shape and line cavities of the brain and spinal cord
Assist in the production, circulation, and monitoring of cerebrospinal fluid (CSF)

Question 21

What are oligodendrocytes

Answer 21

Wrap around axons in the CNS to form myelin sheath
Have many processes that extend to myelinate axons

Question 22

What is myelination

Answer 22

Important function of some neuroglia to wrap myelin around parts of an axon
Insulates the axon and increases the speed at which electrical signals can travel down the axon

Question 23

What is myelin composed of

Answer 23

Mainly fat and appears white

Question 24

What are unmyelinated regions of an axon called

Answer 24

Nodes of Ranvier (neurofibril nodes)

Question 25

Disease associated with demyelination of axons

Answer 25

Multiple sclerosis Leads to neurological symptoms

Question 26

Supporting cell of the PNS

Answer 26

Schwann cell

Question 27

What are Schwann cells

Answer 27

Equivalent to oligodendrocytes as they from myelin sheaths around axons in the PNS