Neurons and Glial Cells Flashcards

Flashcards covering key vocabulary related to neurons, glial cells, and neural communication.

Neuron

Specialized nerve cell responsible for cognition and communication within the nervous system.

Dendrites

The primary receivers of information from surrounding neurons; part of the Input Zone.

Dendritic Spines

Small protrusions on dendrites that increase surface area for more synaptic connections.

Cell Body (Soma)

The processing center of the neuron where incoming signals are combined; part of the Integration Zone.

Axon (Nerve Fiber)

Carries electrical impulses away from the soma toward other neurons or target tissues; part of the Conduction Zone.

Myelin Sheath

A fatty layer produced by glial cells that insulates the axon and increases conduction speed.

Axon Collaterals

Branches of the axon that allow signals to be routed to multiple targets.

Axon Terminals (Synaptic Boutons)

Swellings at the end of the axon that release neurotransmitters into the synaptic cleft; part of the Output Zone.

Motor Neurons

Neurons responsible for triggering movement; typically large with long axons that reach muscles.

Sensory Neurons

Neurons that convey sensory information from peripheral organs to the brain.

Interneurons

Processors within neural circuits that receive information from other neurons, process it, and pass it along.

Multipolar Neurons

Neurons with many dendrites and a single axon; the most common type, involved in integrating extensive inputs.

Bipolar Neurons

Neurons that possess a single dendrite and a single axon, often found in sensory pathways like the retina and olfactory system.

Unipolar (Monopolar) Neurons

Neurons that feature a single extension that branches into dendritic and axonal processes; primarily transmit touch and pain signals from the body to the spinal cord.

Synaptic Vesicles

Structures located in axon terminals that store neurotransmitters.

Synaptic Cleft

A narrow gap approximately 20-40 nanometers wide between neurons where neurotransmitters are released.

Receptors

Specialized sites on the postsynaptic membrane that bind neurotransmitters and determine the nature and strength of the synaptic response.

Electrical Impulses

Rapid firing along the axonal membrane enables quick communication over distances within the nervous system.

Axonal Transport

The movement of molecules and organelles within the axon.

Anterograde Transport

Moves materials such as proteins, organelles, and synaptic vesicles from the soma toward the axon terminals.

Retrograde Transport

Carries materials like worn-out organelles and signaling molecules back to the soma for recycling or further processing.

Glial Cells

Non-neuronal cells that support, protect, and modulate neuronal activity.

Oligodendrocytes

Glial cells found in the CNS that wrap around axons to form myelin sheaths, increasing the speed of electrical conduction.

Schwann Cells

Glial cells located in the PNS that perform similar myelination functions as oligodendrocytes.

Astrocytes

Star-shaped glial cells that weave between neurons, forming a supportive network and contributing to the blood-brain barrier.

Blood-Brain Barrier

A barrier created by astrocytes forming fine blood vessels.

Microglial Cells

Tiny, highly mobile immune cells within the brain that act as clean-up crews, removing debris and responding to injury or infection.