disease of myelin sheath that causes loss of muscle function

-Spinal nerves C1-4 -Innervates muscles attached to hyoid bone and neck

collection of dendrites and cell bodies

pick up stimulus in skin.

located in CNS and connect to motor neurons process stimulus.

many dendrites and a single axon

axons that conduct action potentials toward brain

all neurons outside CNS

-center of spinal cord -looks like letter H or a butterfly

-help remove bacteria and cell debris from CNS -Oligodendrocytes, produce myelin sheath in CNS

one dendrite and one axon

gaps in myelin sheath where action potentials develop.

-where an axon attaches to a muscle, gland, organ, or other neuron - involved with release of neurotransmitters

-Outside of cell is more + (Na*) -Inside of cell is more - (K*)

produce and circulate cerebrospinal fluid (CSF)

- send stimulus to interneurons in spinal cord.

brain and spinal cord

Originates from spinal nerves L1 to S4 - Supply nerves lower limbs

-closed until opened by specific signal. - Na+ channels

-processes stimulus -contains a nucleus

axons that conduct action potentials away from brain

-always open -K+ channels

-Fluid that bathes the brain and spinal cord - Provides a protective cushion around the CNS - Produced in choroid plexus of brain

Contains 3 columns dorsal, ventral, lateral columns

-star-shaped - most abundant - form blood-brain barrier

-Originates from spinal nerves C5-T1 -Supply nerves to upper limb, shoulder, hand

one axon and no dendrites

-outside of spinal cord -contains myelinated fibers

muscle, gland, or organ

receives stimulus from other neurons or sensory receptors

produce myelin sheath in PNS

transmits stimulus to a gland, muscle, organ, or other neuron

send response to effector.

involuntary response to a stimulus

- fatty, protective wrapping around axons -excellent insulator

-two or more neurons synapse same neuron - allows info. to be transmitted in more than one neuronal pathway to converge into a single pathway.

- axon from one neuron divides and synapses with more than one neuron - allows info. to be transmitted in one neuronal pathway to diverge into 2 or more pathways.

collection of axons and their myelin sheath

jumping of action potentials

contain somatic neurons

contain autonomic neurons

contain axons which synapse with interneurons

• Supporting cells for neurons, More numerous than neurons, Can divide to produce more cells