Nerve Cells and Electrical Signaling

A set of vocabulary flashcards covering key concepts in the structure and function of nerve cells and electrical signaling.

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord; processes sensory information and sends responses.

Peripheral Nervous System (PNS)

Composed of neurons that communicate between the central nervous system and the rest of the body.

Afferent Division

Transmits impulses from sensory organs to the central nervous system.

Efferent Division

Transmits impulses from the central nervous system to effectors such as muscles and glands.

Glial Cells

Support cells in the nervous system that account for about 90% of all cells in the nervous system.

Neurons

The functional cells in the nervous system capable of generating and conducting electrical signals.

Astrocytes

Type of glial cell that provides support and regulates chemical levels in the nervous system.

Oligodendrocytes

Glial cells in the CNS that form myelin sheaths around axons.

Myelin Sheath

An insulating layer of fatty tissue that surrounds axons, allowing for faster signal propagation.

Action Potential

A brief reversal of membrane potential in a neuron that conducts electrical signals along the axon.

Depolarization

A change in membrane potential to a less negative or positive value.

Hyperpolarization

A change in membrane potential to a more negative value.

Repolarization

The return of membrane potential to resting state after depolarization.

Graded Potentials

Small changes in membrane potential that can vary in size and decrease in strength with distance.

Temporal Summation

The cumulative effect of multiple stimuli applied in rapid succession.

Spatial Summation

The additive effect of stimuli occurring close together in time from different sources.

Refractory Period

The time following an action potential during which a neuron is unable to fire a new action potential.

Saltatory Conduction

The process by which action potentials jump from one Node of Ranvier to another in myelinated axons.

Sodium-Potassium Pump

A membrane protein that helps maintain resting membrane potential by moving sodium out and potassium into the cell.