Lecture 4: Membrane Potentials & Neurotransmission

Question 1

Name the 3 steps of the process of sodium potassium pump.

Answer 1

1. ATP binds to pump
2. ATP –> ADP + Pi
3. Pump activated, 3 Na+ exit, 2 K+ enter

Question 2

What are the two types of membrane potential changes?

Answer 2

Graded potential, action potential

Question 3

What are the 5 steps of a voltage-gated ion channel?

Answer 3

1. Voltage charge
2. Gate opens
3. Cations enter, depolarization
4. Potential decreases
5. Gate closes

Question 4

What are the 4 steps of a ligand-gated ion channel?

Answer 4

1. Ligand binds receptor
2. Gate opens
3. Cations enter
4. Potential difference decreases because of entry of cations

Question 5

Graded potentials can be summed if they occur near each other, called ___________ ___________. If they occur close in time, it’s called ___________ ___________.

Answer 5

Spatial summation, temporal summation.

Question 6

Name the steps of mighty action potential.

Answer 6

1. Stimulus causes voltage to rise
2. Voltage-gated Na+ channel opens (depolarization)
3. Voltage-gated Na+ closes, K+ opens (hyperpolarization)
4. Membrane returns to resting membrane potential.

Question 7

Electrical activity is muscles is measured by ______________. What is it an tense, long-lasting muscle cramp called?

Answer 7

Electromyography. Tetany.

Question 8

What is nerve conduction? What is neurotransmission?

Answer 8

Nerve conduction is the movement of nerve impulses down neurons. Neurotransmission is the transmission of nerves across synapses.

Question 9

Repolarizing the whole axon is slow, so we use __________ conduction. Why does it work faster?

Answer 9

Saltatory. It works faster because the electrical impulses jump between nodes of Ranvier, the space between the myelin sheaths of the axon body.

Question 10

What are the 3 steps of neurotransmission?

Answer 10

1. Calcium rushes into the axon, causes acetylcholine to bond with presynaptic membrane of another neuron.
2. Acetylcholine attaches to the receptor of the neuron.
3. Broken down by receptors into acetyl and choline, returns to original dendrite.

Question 11

Name 3 types of neurotransmitters. What is nerve gas?

Answer 11

Biogenic amines, serotonin, histamines, amino acids, peptides, acetyl choline, etc. Nerve gas is acetylcholinesterase inhibitor, antidote is Atropine.