Neurophysiology - L1

Question 1

Three Main Tasks of The Nervous System

Answer 1

1) Monitor - the sensory system
2) Analyze - get incoming info, integrate it and make decision
3) Motor - Send Signals to the muscle

Question 2

Depolarization

Answer 2

Makes Membrane Potential less negative

Question 3

Hyperpolarized

Answer 3

makes the membrane potential more negative

Question 4

Ion Distribution (Na, K, Cl, Ca)

Answer 4

Na - 150mM Outside, 15mM inside
K - 15mM Outside, 150mM mM Inside
Cl - 110mM Outside, 10mM inside
Ca - 2mM Outside, 10^-4mM Inside

Question 5

The Nernst Equation

Answer 5

At body Temp

Ei = 61/Z log [ions outside]/[ions inside]

Question 6

Driving Force (Equation)

Answer 6

DF = Vm - Ei

Question 7

I (Current)

Answer 7

Is the rate of flux of ions, which is proportinal to the Driving Force

Question 8

Conductance

Answer 8

AKA the permeability it is the number of open channels and how leaky the cell is to an ion. This is represented by the letter g

Question 9

How To Calculate permeability when no net flow of ions

Answer 9

gNa(Vm-ENa) = -gK(Vm - Ek)

In parenthesis is the driving force. The driving force combined with the permeability will have to be equal when there is no net flow of ions.

Vm sits closer to the larger permeability

Question 10

Why is Vm Negative

Answer 10

MAJOR KEY: It is because of the potassium leak channels

Question 11

Sodium - Potassium Pump

Answer 11

Use ATP to pump 3 Sodium out 2 potassium in
thus it makes a current more negative
If pump is blocked Vm would go up a slight amount but not much. After much time the gradient would be lost