Chapter 13 - Nueronal Communication

Question 1

What is the definition of homeostasis

Answer 1

The maintenance of a constant internal environment

Question 2

What are the three types of nuerone

Answer 2

Relay

Motor

Sensory

Question 3

What is the definition of a nuerone

Answer 3

Specialised cells that rapidly transmit electrical impulse

Question 4

Describe structure of motor nuerone

Answer 4

1 long axon and many short dendrite with nucleus at one end

Question 5

Structure of sensory neurone

Answer 5

1 axon and 1 dendron with nucleus in middle of cell body

Question 6

In which direction does an axon carry an electrical impulse

Answer 6

Away from cell body

Question 7

What is the structure of relay neurone

Answer 7

Many short axons and dendrite

Question 8

What does a sensory cell send impulse on to

Answer 8

Relay or motor neurones

Brain

Question 9

Where does motor neuron recieve impulse from

Answer 9

Either relay or sensory neurones

Question 10

Where does motor neurone send impulse to

Answer 10

Effector

Question 11

Where does a relay neurone receive and send impulses to

Answer 11

Between all neurones

Question 12

Where does sensory neurone send impulse to

Answer 12

Relay

Motor

Brain

Question 13

What are key features to neurone

Answer 13

Mitochondira and endoplasmic reticulum

Enable production of neurotransmitters

Question 14

What is the flow of an electrical impulse?

Answer 14

Receptor

Sensory

Relay

Motor

Effector

Question 15

What is myelin sheath made of

Answer 15

Layers of plasma membrane

Question 16

What produces layers of membrane that make up myelin sheath

Answer 16

Schwann cells

Question 17

What is the role of myelin sheath

Answer 17

To increase rate of transmission

Question 18

What are the gaps in myelin sheath called and what is there purpose?

Answer 18

Nodes of ranvier

To increase rate of transmission by making impulse jump

Question 19

What is potential difference

Answer 19

The difference in charge on 2 sides of membrane

Question 20

When resting what is the state of membrane charge

Answer 20

polarised

Question 21

What is resting potential on inside of nuerone

Answer 21

-70mv

Question 22

For each molecule of ATP hydrolysed how many molecules are pumped

Answer 22

3 NA

2K

Question 23

What is the name of the mechanism used to pump ions in nuerone

Answer 23

Sodium-pottasium pump

Question 24

Is sodium moved in or out of nuerone

Answer 24

Out

Question 25

What is charge on sodium ion

Answer 25

+

Question 26

What is overall charge on outside of cell

Answer 26

Negative

Question 27

To produce an impulse what does charge have to change to

Answer 27

+40mv

Question 28

How is the change in charge achieved in nuerome

Answer 28

Membrane becomes more permeable to NA+

Question 29

How does movement of NA+ cause depolarisation

Answer 29

Na+ is actively pumped out of nuerone

When permeability increases NA+ moves back in the charge increases

Question 30

What are the 5 stages of an action potential

Answer 30

Resting potential

All or nothing principle

Depolarisation

Channel movement

Repolarisation

Hyperpolarisation

Question 31

What has to be reached for action potential to occur

Answer 31

Threshhold value

Question 32

What can effect threshold value

Answer 32

The frequency of impulse as all impulse same size

Question 33

What happens when NA+ change charge to threshold value

Answer 33

Action potential produced

Question 34

When the inside of nuerone is positive what is the term for this state

Answer 34

aDepolarised

Question 35

What happens after threshold value had been reached in terms of channels

Answer 35

Na + channel close

K+ channel open