Week 3 Terms

Question 1

Action potential

Answer 1

This is how neurons send signals electrically down their axons

Question 2

Voltage gated K+ channel

Answer 2

Opens at +40 mV

Question 3

Voltage gated Na+ channel

Answer 3

opens at -50 mV

Question 4

Na+/K+ pump

Answer 4

lets three Na+ out, two K+ in

Question 5

Process of action potential

Answer 5

1. Neuron at rest; depolarization
2. Neurotransmitters from neighbor neuron bind to dendritic receptor sites and open ion channels
3. Sodium Rushes in, changing voltage inside neuron to positive and diffusing down the membrane
4. Once the neuron reaches a high enough voltage, K+ channels open and K+ rushes out
5. Shortly after K+ channels open, Na+ channels close and the cell begins to decrease in charge again as potassium rushes out
6. The neuron overcorrects to a negative charge
7. Diffusion through the cell membrane corrects the voltage slightly and the sodium potassium pump maintains the negative voltage

Question 6

Neuron at rest

Answer 6

inside of cell is -70mV

Question 7

Depolarization

Answer 7

Inside of the cell becomes positive and the outside is negative

Question 8

Repolarization

Answer 8

When the Na+ channels close (while K+ rushes out of the cell) and the cell becomes negative on the inside and positive on the outside

Question 9

Diffusion

Answer 9

The process of moving molecules from a high concentration to a low concentration

Question 10

Synaptic Transmission

Answer 10

How the electrical signal of an action potential is changed into a chemical signal at the synapse

Question 11

Synaptic Transmission Components

Answer 11

• Voltage-gated calcium channels
• Calcium-sensitive proteins
• Synaptic vesicles
• Neurotransmitters
• Receptors and ion channels

Question 12

Action Potential Card sort (9 parts)

Answer 12

1. The action potential invades the axon terminal
2. NTs diffuse into synaptic cleft and bind to postsynaptic receptors
3. Voltage-gated Ca2+ channels detect entrance of action potential and open
4. Postsynaptic receptors open ion channels open on the postsynaptic membrane, allowing ions to flow into the postsynaptic cell.
5. Ca2+ flows into the cell
6. Allowing ions to flow into the postsynaptic cell begins the process of that cell being able to reach threshold and fire an action potential
7. Ca2+ sensitive proteins detect changes in Ca2+ and fuse synaptic vesicles to the cell membrane
8. Excess neurotransmitters left within the synaptic cleft are degraded by enzymes or reuptaked back into presynaptic cell and recycled
9. Neurotransmitters (NTs) are released into the synaptic cleft.