LT2 - Nervous System

Nerve cells/neurons FUNCTION

recieving and transmitting electrical impulse/found in brain, spinal cord, peripheral nerves

nerve cells/neuron TYPES

sensory, interneurons, motor

Glial cells/neuroglia FUNCTION

support neurons by providing nourishment, structure support, protection

Glial cells/neuroglia TYPES

oligodendrocytes, astrocytes, microglia, ependymal cells, Schwann cells

Dendrite

Branched extensions; carry impulses to cell body

cell body/soma

Houses cell organelles including the nucleus

Axon

Long fiber; carries impulses away from cell body

Schwann cell

Glial cells wrapped around axon; produce myelin

myelin sheath

Lipid-rich substance; insulates the axon

node of ranvier

Gaps between Schwann cells; uninsulated axon

axon terminal

Microscopic branches at end of axon

synaptic bulb

Ends of axon terminal; release neurotransmitters

Sensory/afferent neuron

transmit impulse from sensory receptor to CNS (most unipolar)

Interneurons/association neuron

transmit impulse between sensory and motor neurons, determine response (most multipolar)

Motor/efferent neurons

relay impulse AWAY from CNS to effector muscles and glands (most multipolar)

Oligodendrocytes

Wrap around CNS neurons form sheaths made of myelin; speed up nerve impulse transmission (in CNS)

astrocytes

star shaped, anchor neuron to blood vessel, control exchange of material, make blood/brain barrier (in CNS)

Microglia

thorny glial cell, ingest microbes, defend neurons against pathogens (in CNS)

ependymal cells

cuboidal cells, form epithelial lining of cavities in brain/spinal cord (in CNS)

schwann cells

wrap around PNS neurons, form sheaths made of myelin, speed up nerve impulse transmission (in PNS)

Reflex arc