Lesson: Nervous Part 1 - 8.2 Definitions

Question 1

Action potential

Answer 1

A nerve signal due to electricity created by the movement of sodium and potassium ions.

Question 2

Resting neuron

Answer 2

No action potentials are being sent when the neuron is at rest.

Question 3

Membrane potential

Answer 3

The difference in charges on the outside of the neuron and the inside.

Question 4

Depolarization

Answer 4

Sodium ions rushing into the cell

Question 5

Repolarization

Answer 5

Potassium ions rushing out of the cell

Question 6

Threshold

Answer 6

The amount of sodium needed to start an action potential.

Question 7

Polarized

Answer 7

The neuron is charged up and ready to go.

Question 8

Stimulus

Answer 8

Some type of reaction that causes the “gated channels” to open. Typically chemical.

Question 9

Presynaptic Neuron

Answer 9

The neuron that brings the nerve signal to the synaptic junction.

Question 10

Postynaptic Neuron

Answer 10

The neuron that receives the nerve message at the synaptic junction.

Question 11

ECF

Answer 11

Extracellular fluid – fluid outside the cell

Question 12

ICF

Answer 12

Intracellular fluid – fluid inside the cell

Question 13

Chemical (Ligand) Gated Channel

Answer 13

A protein channel in the plasma membrane that is opened or closed when chemicals such as neurotransmitters attach to their receptors.

Question 14

Voltage Gated Channels.

Answer 14

A protein channel in the plasma membrane that is opened or closed by electricity (voltage).

Question 15

Local Potential

Answer 15

Only occurs at the dendrites and cell body (soma). This is due to the opening of chemical (ligand) gated channels opening and allowing sodium into the cell.

Question 16

Synapse

Answer 16

In this class, we only use synapse for where two neurons meet.

Question 17

Membrane Channel Protein

Answer 17

In the phospholipid layer of the plasma membrane are membrane proteins that span the phospholipid layer. Channels are located that connect the ECF with the ICF.