Mod 10 - Cells of the Nervous System

What does a neuron do

Receive stimuli and transmit action potential

what are neuroglia cells

non-neural cells that support and protect neurons

What is a dendrite?

short extensions of cell body

input part of neuron

What does the trigger zone of the axon contain

Axon hillock (cone shaped)

initial segment (start of axon)

What are vesicles (neurotransmitters)

located in the presynaptic terminal where a neurotransmitter is released to make the action potential across a synapse

Sensory and afferent go ________ the CNS

towards

Motor and efferent go _________ the CNS

away

Interneurons

Connect neurons together

Multipolar neuron

Many dendrites, single axon

Most CNS and motor neurons

Bipolar Neuron

1 dendrite, 1 axon

Specific sensory organs such as eye

Unipolar neurons

single process extending from cell body, divides into 2 branches

Astrocytes

Form foot processes (cover blood vessels, neurons)

create blood brain barrier

ependymal cells

Lines the ventricles of the brain and central canal of spine

Produces central spinal fluid

Microglia

protective mechanism for the CNS

Phagocytic

Oligodendrocytes

Forms myelin sheaths in CNS around multiple axons

Schwann cells

wraps around a singular axon in the PNS

Satellite cells

Surround neuron cell and provides nutrients

What does myelin sheaths do

Protects and insulates axon as well as increases signal rate

Tract

Bundle of myelinated axons in CNS (nerves of CNS)

Nucleus

Collection of neuron cell bodies in CNS (ganglion of CNS

White Matter

Nerve tracts that transport action potentials in CNS

Gray Matter

connected to nerve terminals in CNS (decision makers)

Gray and white matter distribution in brain and spinal cord

Brain - gray outside, white inside

Spine - White outside gray inside