A&P - Chapter 18 (Part 3)

Question 1

What do Schwann cells do? (2)

Answer 1

1. Support nerve fibres

2. Forms a myelin sheath on axons in the PNS

Question 2

What do schwann cells have a similar function to?

Answer 2

Oligodendrocytes in the CNS

- wraps itself around the axons of the neurons

Question 3

What does myelin act as?

Answer 3

An insulator

Question 4

What is myelin formed by in the CNS?

Answer 4

Oligodendrocytes

Question 5

What is myelin formed by in the PNS?

Answer 5

Schwann cells

Question 6

What are unmyelinated spaces called?

Answer 6

Nodes of Ranvier

Question 7

What is the node of Ranvier capable of generating? Why?

Answer 7

1. Electrical activity
   - saltatory conduction
2. Not insulated

Question 8

Saltatory conduction

Answer 8

Allows for rapid and effective transmission of a nerve impulse

Question 9

Saltatory

Answer 9

Jumping

Question 10

What are neurons?

Answer 10

Excitable cells that initiate and conduct impulses that make all nervous system functions possible
- structural/functional units of the NS

Question 11

What are the 3 main parts of the nervous system?

Answer 11

1. Dendrites
2. Cell body
3. Axon

Question 12

What does the cell body contain? (2)

Answer 12

1. Nucleus

2. Organelles

Question 13

What are dendrites?

Answer 13

Branching projections

Question 14

What do dendrites do?

Answer 14

They conduct impulses to the cell body

Question 15

What is the main part of the neuron?

Answer 15

The cell body

Question 16

Where is the cell body found?

Answer 16

In the CNS

- or close by

Question 17

Axon

Answer 17

Long, single projection from the cell body

Question 18

Is the axon myelinated?

Answer 18

Sometimes

Question 19

What does the axon do?

Answer 19

Transmits impulses away from the cell body

Question 20

How do the distal tips of the axon terminate?

Answer 20

In a synaptic knob

Question 21

What are the distal ends in sensory neurons of dendrites?

Answer 21

Shorter

Question 22

What are the 3 types of structures of a neuron?

Answer 22

1. Multipolar
2. Bipolar
3. Unipolar

Question 23

Multipolar structure

Answer 23

Multiple extensions from the cell body

Question 24

Bipolar structure

Answer 24

Exactly 2 extensions from the cell body

Question 25

Unipolar structure

Answer 25

Exactly 1 extension from the cell body

Question 26

What are 3 types of functions of a neuron?

Answer 26

1. Sensory
   - afferent
2. Motor
   - efferent
3. Interneurons
   - sensory to motor

Question 27

What happens if neurons are damaged?

Answer 27

They wont duplicate because once damaged they cant repair

Question 28

What type of nervous cell is most likely to be cancerous? Why?

Answer 28

1. Glia cells

2. Because they reproduce