Module 2 part 2

Question 1

What is the advantage of myelinated neurons

Answer 1

Myelin enables rapid signal conduction in a small diamter axon in a compact space

Question 2

Define the membrane time constant

Answer 2

a way of measuring how quickly a neuron’s voltage level decays to its “resting state” after it receives an input signal. When the membrane constant is large, it takes the cell longer to get to peak of level of voltage

Question 3

Electrochemically, what does Cl- do?

Answer 3

Found in higher concentration outside the cell, the opening of Cl- channels causes in flow of the ion, causing hyperpolarization

Question 4

What is the connection between capacitance and the membrane time constant?

Answer 4

The membrane time constant is a reflection of the capacitance. As the membrane time constant increases, so does the capacitance

Question 5

In the context of neuron biology, define de-activation

Answer 5

Closing the activation gate

Question 6

Define AP amplitude

Answer 6

The number of mV from resting to peak

Question 7

Define the relative refractory period

Answer 7

The minimum time required for successive identical stimuli to achieve identical action potentials

Question 8

What is a plateau phase?

Answer 8

Extended period of depolarization

Question 9

Define synaptic plasticity

Answer 9

Post synaptic potential (PSP) is variable and depends on stimulus input from the presynaptic neuron

Question 10

How does Ca2+ regulate neurotransmitter release?

Answer 10

An action potential will cause voltage-gated Ca2+ channels to open in the pre-synaptic terminal. Increase Ca2+ will cause the release of neurotransmitters.

Question 11

Define synaptic facilitation

Answer 11

Increased pre-synaptic APs will increase neurotransmitter release