Neuronal Action Potentials and Functions

The video explains how neurons, the cells of the nervous system, transmit messages through nerve impulses. It details the electrochemical process of action potentials, including the roles of sodium and potassium ions, and the phases of depolarization and repolarization. The sodium-potassium pump and refractory period are discussed, along with how impulses travel through neurons like a wave. Graphical representations of neuron charge changes are provided to aid understanding.

What is the primary function of neurons in the nervous system?

• To transmit messages throughout the body

• To store energy

• To digest food

• To produce hormones

How does a nerve impulse travel through a neuron?

• As an electrochemical process

• As a thermal expansion

• As a chemical reaction

• As a mechanical wave

What ions are primarily involved in the action potential of a neuron?

• Hydrogen and oxygen

• Chloride and bicarbonate

• Sodium and potassium

• Calcium and magnesium

What happens during depolarization in a neuron?

• Potassium ions enter the neuron

• Sodium ions exit the neuron

• Chloride ions exit the neuron

• Sodium ions enter the neuron

What is the charge of a neuron at rest?

• Zero millivolts

• Positive 40 millivolts

• Negative 70 millivolts

• Negative 90 millivolts

What is the result of the sodium gates opening during an action potential?

• The neuron becomes more negative

• The neuron becomes more positive

• The neuron releases neurotransmitters

• The neuron remains unchanged

What is the role of the sodium-potassium pump in neurons?

• To break down glucose

• To produce neurotransmitters

• To maintain ion balance by moving sodium out and potassium in

• To generate electrical signals

What is the refractory period in the context of neuron activity?

• A period when the neuron is generating maximum impulse

• A period when the neuron is hyperactive

• A period when the neuron is at rest

• A period when the neuron cannot be depolarized again

During which phase does the neuron charge drop below the resting potential?

• Depolarization

• Repolarization

• Hyperpolarization

• Resting state

What happens to chloride ions during hyperpolarization?

• They remain unchanged

• They are converted to sodium ions

• They enter the neuron

• They exit the neuron