Neurons and other cells that produce what type of potentials are said to have membrane excitability?

Cells, particularly neurons, have the ability to generate action potentials, which are rapid and significant changes in membrane potential. This phenomenon, known as membrane excitability, is fundamental to the function of nerve cells. When a neuron is stimulated adequately, it depolarizes, leading to the generation of an action potential that travels along the axon, facilitating communication between cells.

Action potentials are all-or-nothing events, meaning that once the threshold is reached, the action potential is generated to completion, allowing for consistent and rapid signaling. This is crucial in the nervous system, as it enables the transmission of information over distances and coordinates responses in the body.

In contrast, while resting potentials refer to the stable voltage across the membrane of a neuron when it is not actively transmitting signals, graded potentials are small changes in membrane potential that can lead to an action potential if they are of sufficient magnitude. Continuous potentials do not align with the established physiological definitions regarding neuronal signaling. Thus, the emphasis on action potentials as the hallmark of membrane excitability underscores their critical role in the functionality of neurons and other excitatory cells.