Electrophysiology

Question 1

How did we find out that animals use electricity to control muscle

Answer 1

By electrocuting a frog. by Luigi Galvani

Question 2

What has a massive concentration gradient out of the cell

Answer 2

K+

Question 3

What has a massive concentration gradient into the cell

Answer 3

Na+

Question 4

What supplies the energy for the sodium potassium concentration gradient

Answer 4

ATP

Question 5

How many Na+ goes out per ATP

Answer 5

3 molecules

Question 6

How many K+ goes in per ATP

Answer 6

2 molecules

Question 7

What happens the more the pump occurs

Answer 7

The intracellular fluid becomes negatively charges and vice versa

Question 8

What is the diffusion of ions determined by

Answer 8

Membrane permeability, concentration gradient, voltage gradient

Question 9

What ions can go in easier than the other type

Answer 9

cations

Question 10

What is a K+ leak channel

Answer 10

Lose the potassium

Question 11

Is the membrane more permeable to K+ or Na+

Answer 11

K+

Question 12

What also contributes to the -ve charge (NOT ATP)

Answer 12

Proteins

Question 13

What is a leak channel

Answer 13

Always open, always leak a specific chemical

Question 14

What is a ligand gated channel

Answer 14

Open or shut by a specific chemical messenger

Question 15

What is a voltage gated channel

Answer 15

Open or shut by voltage

Question 16

What is depolarisation

Answer 16

Make the cell less charged by adding Na+ to the cell

Question 17

What is hyperpolarisation

Answer 17

Makes the cell more charged by removing K+ to the cell

Question 18

What cells has the ability to amplify

Answer 18

Nerves and muscles

Question 19

Why can they amplify polarisation

Answer 19

Because they have voltage gates

Question 20

What is the action potential

Answer 20

Electrical excitability which is done via voltage gates

Question 21

What happens at the start of depolarisation

Answer 21

Ligand gates which initially depolarise the cell

Question 22

What happens after the ligand gates initially depolarise

Answer 22

The voltage gates open, letting sodium in

Question 23

What happens after the voltage gates open

Answer 23

they lock for a few seconds then close

Question 24

What happens with K+ channels

Answer 24

They do not lock, they only close

Question 25

Which channel is faster (Na+ or K+)

Answer 25

Na+

Question 26

What happens first

Answer 26

the Na+ comes in first then the K+ comes out

Question 27

What happens when the K+ channels open

Answer 27

Repolarisation

Question 28

How do we get the Na+ out and the K+ in after repolarisation

Answer 28

Through the Na+ K+ pump

Question 29

What is the absolute refractory period

Answer 29

When the Na+ channel is locked

Question 30

What is the difference between locked and closed (in this context)

Answer 30

locked = no input can open it, closed = a certain threshld can open it

Question 31

What is the relative refractory period

Answer 31

Where higher stimulus is required

Question 32

Are there varying sizes of action potentials

Answer 32

No

Question 33

What is the difference between strong and weak stimulus

Answer 33

Strong stimulus has a higher quantity of signals than weak ones

Question 34

What happens when one part is depolarised

Answer 34

It spreads through propogation

Question 35

How quickly does the nerves move without myelin

Answer 35

2m/s

Question 36

How do neurons speed up

Answer 36

through insulated myelin sheaths which jumps through the insulated schwann cells

Question 37

What makes this speed up

Answer 37

Jumping

Question 38

What is ogliodenedrites

Answer 38

central nervous system schwann cells