Action potentials generation and transmission part 2

Question 1

Describe mylienated axon

Answer 1

AP fast

larger in diameter

Question 2

Describe unmylienated

Answer 2

slow

smaller diameter

Question 3

What are the two stages of action potential transmission

Answer 3

passive spread

generation of action potentials

Question 4

Describe passive spread

Answer 4

1. depolarisation at one region of the membrane
2. passive current flow (inside and outside the axon)
3. depolarization of adjacent part of membrane

Question 5

Describe passive spread of AP

Answer 5

current quickly dissipates as it flows along the axon

Question 6

AP potential transmission in unmyelinated axons

Answer 6

1. Action potential
2. Passive current flow
3. Depolarisation of adjacent membrane to threshold
4. Na channels open of adjacent membrane
5. New full on AP occurs in adjacent part of the cell

Question 7

Describe the generation of action potential in an unmyelinated cell

Answer 7

AP is slow as AP needs to generated at every point within the axon

Question 8

Describe the generation of action potential within a mylienated axon

Answer 8

due to insulation less current (AP) dissapates as it flows down the axon

Aps do not need to be generated every time

Question 9

Describe passive flow

Answer 9

Passive flow is both left and right

Question 10

What is the separation between the myelinated sheath called

Answer 10

node of ranvier

Question 11

Where do action potentials occur in a myelinated sheath

and what is this process called

Answer 11

They occur within the node of Ranvier

This is called the saltatory conduction

Question 12

What does the PNS sensory path have

Answer 12

Sensory neurons and

Motor neurons which from the Autonomic Nervous System

Question 13

Descrive AP in sensory neurons

Answer 13

1. AP is not intially evokes
2. First graded depolarisation occurs as the receptor potential
3. Receptor potential spreads passively to trigger zone where AP is generated
4. AP moves through axon to the CNS

Question 14

How is strength of stimulus accounted for

Answer 14

aptitude of the refractory receptor potential and the frequency of AP