Lecture 4 - Basics of Neurology II

Question 1

Step by step guide on ion concentration

Answer 1

1) where is the ion most concentrated?
inside or outside the neuron (outside)

Therefore the ion will flow
inside or outside the neuron (into)

Given the ions charge the how will this alter the distribution of charges
inside more positive or negative (inside more positive)

Question 2

Nernest Equation

Answer 2

Nernest equation allows us to calculate voltage at equilibrium

Equilibrium ion concentration is equal to ideal gas conc x temperature divided by ion charge x faraday constant, multiplied by out concentration divided by inside concentration

Question 3

Nernest Equation rules

Answer 3

sodium and potassium same, 58 log

Chloride you flip the reciprocal

calcium uses 29 log

Question 4

millivoltage numbers

Answer 4

at rest neuron -65
potassium -84
sodium 67
cholride -67
calcium 116

Question 5

Two factors that determine resting potential of a neuron

Answer 5

1) permeable to potassium via leak channels
2) potassium is more concentrated inside then out

Action potential = become more positive

Question 6

Permeability

Answer 6

At rest potassium most permeable but at start of AP sodium more permeable

Question 7

Goldman Equation (look up)

Answer 7

measure permeability and uses a ratio. at rest delporization and hyperpolerization

Question 8

Process open to close

Answer 8

1) all voltage gated channel closed (rp)
2) small amount of Na enter neuron, membrane potential becomes more positive leading to more channels to open
3) Na channels begin to inactivate while more potassium channels open
4)Most voltage channels closed but some still open along with leak ones meaning potassium is more permeable and voltage is below -65