Physiology Flashcards

Front

What is an action potential?

Back

A rapid, all-or-nothing electrical signal that travels along the neuron's axon.

Front

What triggers an action potential?

Back

It is triggered when the membrane potential reaches a certain threshold.

Front

What happens during depolarization in an action potential?

Back

Sodium (Na⁺) channels open, and Na⁺ rushes in, making the inside of the cell more positive.

Front

What happens during repolarization in an action potential?

Back

Potassium (K⁺) channels open, and K⁺ exits, making the inside of the cell negative again.

Front

What happens during hyperpolarization in an action potential?

Back

The membrane potential drops below the resting potential briefly before stabilizing.

Front

What is a graded potential?

Back

A small, localized change in membrane potential that varies in size and can be excitatory or inhibitory.

Front

Where do graded potentials occur in a neuron?

Back

Graded potentials occur in the dendrites and cell body.

Front

How do graded potentials differ from action potentials?

Back

Graded potentials vary in size and are not all-or-nothing, while action potentials are uniform and all-or-nothing.

Front

What is summation in graded potentials?

Back

Summation refers to the process where graded potentials can add together to reach the threshold and trigger an action potential.

Front

What are the main parts of the CNS?

Back

The brain and spinal cord.