brain and spinal cord

all neurons outside CNS

receives stimulus from other neurons or sensory receptors

-processes stimulus -contains a nucleus

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

- fatty, protective wrapping around axons -excellent insulator

gaps in myelin sheath where action potentials develop.

jumping of action potentials

disease of myelin sheath that causes loss of muscle function

many dendrites and a single axon

one dendrite and one axon

one axon and no dendrites

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

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

produce and circulate cerebrospinal fluid (CSF)

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

produce myelin sheath in PNS

collection of dendrites and cell bodies

collection of axons and their myelin sheath

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

-always open -K+ channels

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

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

involuntary response to a stimulus

pick up stimulus in skin.

- send stimulus to interneurons in spinal cord.

send response to effector.

muscle, gland, or organ

located in CNS and connect to motor neurons process stimulus.

-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.

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

-outside of spinal cord -contains myelinated fibers

Contains 3 columns dorsal, ventral, lateral columns

axons that conduct action potentials toward brain

axons that conduct action potentials away from brain

contain axons which synapse with interneurons

contain somatic neurons

contain autonomic neurons

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

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

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

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