Impulse Transmission

Question 1

Neuron

Answer 1

-transmits an electrical pulse

Question 2

Polarized (neuron at rest)

Answer 2

• neuron has resting potential
• resting potential: potential difference between the inside & outside of axon membrane at rest
• resting membrane potential -70mV

Question 3

Outside axon membrane

Answer 3

• extracellular

- more positive

Question 4

Inside axon membrane

Answer 4

• cytoplasm

- more negative

Question 5

Depolarized (transmitting/firing)

Answer 5

• increasing membrane potential to greater than resting potential (-70mV)
• in order for neuron to fire stimulus must have a minimum charge
• must be above threshold of potential (-55mV)
• known as all or none response
  ex: gun will either fire or not
• if stimulus s above threshold an action potential occurs

Question 6

Action Potential

Answer 6

• change in charge of the axon membrane from -70mV towards 0mV (with an overshoot to 35mV)
• occurs on all locations on unmyelinated neurons
• on the nodes of myelinated neurons (saltatory)

Question 7

Depolarization Gates

Answer 7

• sodium gates open
• potassium gates close
• sodium rushes in

Question 8

Repolarized (neuron recovering)

Answer 8

• after neuron fires theres a short period of time when it can’t fire or generate an impulse
• refractory period
• the movement of positive charge outside axon membrane restores resting potential