chapter 11 lectures

The plasma membrane of a neuron is normally permeable to ions.

False

Which ions are involved in setting up the resting membrane potential?

Sodium, potassium & chloride

What ion is mentioned as having a higher concentration inside the neuron?

Potassium

Electrical activity in the body can continue without maintaining ion gradients.

False

What type of channel is always open and allows potassium to leak?

Leakage or passive channel

Which factors determine whether potassium leaks out or back into the cell?

Chemical gradient & electrical gradient

What is involved in the electrochemical gradient across the neuron membrane?

Diffusional or chemical gradient & Electrical gradient

What happens when the potassium ions leak out leaving behind a negative charge inside the neuron?

The inside becomes negatively charged

What is the resting membrane potential that is mentioned for a neuron in this video?

Negative 70 millivolts

The sodium-potassium pump is responsible for maintaining the resting membrane potential.

True

Which of the following are characteristics of graded potentials?

Short-lived & Decrease in intensity with distance

True or False: Both action and graded potentials involve depolarization, repolarization, and hyperpolarization.

True

True or False: Action potentials can vary in strength.

False

What creates the resting membrane potential?

Leakage channels for potassium and sodium

True or False: The relative refractory period occurs during hyperpolarization.

True

What does the term 'saltatory conduction' refer to?

Jumping of electrical current between nodes of Ranvier

During resting membrane potential, which ions are high inside and outside the cell?

Potassium is high inside the cell & Sodium is high outside the cell

What maintains the resting membrane potential in a neuron?

Sodium-potassium pump

Sodium flows into the cell by diffusion during action potential.

True

Which neurotransmitter is mentioned as an example that opens chemical gates in neurons?

Acetylcholine

What occurs when sodium enters the neuron, making its inside more positive?

Depolarization

What is the usual threshold potential for generating an action potential?

-55 millivolts

What changes occur across the axon during an action potential?

Opening of voltage gates & Generation of depolarization events

Potassium flows out of the cell during depolarization.

False

Opening of sodium gates is responsible for the action potential.

True

In which locations are graded potentials primarily found?

Dendrites & Cell bodies (soma)

Which ion movement is responsible for depolarization during an action potential?

Sodium ions entering the cell

Which factors determine the speed of conduction along an axon?

Axon diameter & Presence of myelin sheath

How are nerve fibers classified according to the video?

Diameter, degree of myelination, and speed of conduction