Psych 2: Action Potential

What is the function of the axon hillock?

• To initiate the action potential

• To receive neurotransmitters from other neurons

• To store excess neurotransmitters

• To regulate the release of neurotransmitters

What happens during depolarization?

• The inside of the cell becomes less negative

• The cell membrane threshold is met

• The inside of the cell becomes more negative

• Voltage-gated K+ channels open

What happens when voltage-gated Na+ channels open during the action potential?

• The cell hyperpolarizes

• The cell repolarizes

• K+ leaves the cell

• Na+ enters the cell

What is the characteristic of the action potential?

• Loses strength as it travels

• Graded

• All-or-none

• Depolarizes the cell membrane

What is the function of myelin in neuronal communication?

• Leads to cognitive disability

• Speeds up the propagation of the action potential

• Causes poor motor coordination

• Slows down the propagation of the action potential

What is the effect of multiple sclerosis on action potentials?

• Improves cognitive function

• Slows or stops APs

• Speeds up APs

• Enhances motor coordination

What is the cumulative effect of repeated stimulus?

• Temporal summation

• Spatial summation

• Absolute refractory period

• Relative refractory period

Where do EPSPs occur?

• Dendrites and soma

• Axon

• Presynaptic neuron

• Postsynaptic neuron

What is the characteristic of IPSPs?

• Hyperpolarizations

• Depolarizations

• All-or-none

• Graded

What is the probability of an action potential firing?

• Absolute refractory period

• Spatial summation

• Temporal summation

• EPSPs:IPSPs