Introduction to Neurons and Glial Cells

This set of flashcards covers essential vocabulary and definitions related to neurons and the nervous system.

Axon Hillock

The part of a neuron where the action potential begins.

Nodes of Ranvier

Gaps in the myelin sheath that improve conduction of electrical signals along the neuron.

Processes

Long protrusions from neurons, including dendrites and axons.

Unipolar Neurons

Neurons with one process that acts as both a dendrite and axon; mostly pseudo unipolar in humans.

Bipolar Neurons

Neurons with two distinct processes: one dendrite and one axon.

Multipolar Neurons

Common neurons with multiple dendrites and a single axon, typically involved in motor function.

Astrocytes

Star-shaped glial cells that provide support, regulate ion concentration, and help form the blood-brain barrier.

Oligodendrocytes

Glial cells in the central nervous system that produce myelin to insulate neurons.

Microglia

Small glial cells that act as the immune cells of the central nervous system, removing debris and pathogens.

Ependymal Cells

Glial cells that help produce cerebrospinal fluid and line the ventricles of the brain.

Satellite Cells

Glial cells in the peripheral nervous system that function similarly to astrocytes.

Schwann Cells

Glial cells in the peripheral nervous system that wrap around axons to create myelin.

Myelin

A fatty substance that insulates axons, increasing the speed of electrical impulses.

Blood-Brain Barrier (BBB)

A selective barrier that prevents certain substances in the blood from entering the brain.

Graded Potential

A change in the membrane potential that varies in size, depending on the strength of the stimulus.

Action Potential

A rapid and large change in membrane potential that travels along the axon of a neuron.

Ion Channels

Proteins that allow ions to flow into or out of a cell, crucial for the generation of action potentials.

Neuromuscular Junction

The connection between a motor neuron and a muscle fiber where neurotransmitters are released.

Acetylcholine

A neurotransmitter released at neuromuscular junctions that depolarizes muscle fibers, triggering contraction.

Demyelination

The loss or damage of myelin sheath around nerves, leading to impaired nerve function.

Multiple Sclerosis

An autoimmune disease that targets myelin in the central nervous system, affecting motor control.

Guillain-Barre Syndrome

An autoimmune disorder affecting the peripheral nervous system, causing weakness and sensory loss.