1.2: nervous system

cns

brain and spinal cord

pns

everything but brain and spinal cord

pns 2 divisions

somatic: voluntary movement of skeletal muscles

autonomic: sympathetic & parasympathetic: involuntary movement of smoother muscles & organ glands

sensory nerves

coney info from the body to CNS

motor nerves

transmit info from the CNS to muscles & glands

somatic nerves connect:

brain/major muscles & sensory systems

autonomic nerves connect:

viscera

cranial nerves

innervate the head, neck, & visceral organs directly from the brain

spinal nerves

connect the spinal cord, bring in sensory info, and sent out motor info

spinal nerve names

cervical, thoracic, lumbar, sacral, coccygeal

spinal nerves have:

a group of motor axons that project from the spinal cord & a group of sensory axons that enter the spinal cord

sensory info enters

dorsally; afferent

motor info leaves

ventrally; efferent

sympathetic

fight or flight

parasympathetic

rest and digest

norepinephrine

chemical used in sympathetic ns

acetylcholine

used in sympathetic and parasympathetic ns

hypothalamus

sympathetic and parasympthathetic are both controlled by

sympathetic chain

sympathetic system activates as a whole unit; thoracic

parasympathetic chain

doesnt have one; target organs activate independently; cranial & sacral

ganglia

group of cell bodies in peripheral nervous system

parasympathetic neurotransmitters

preganglionic: acetylcholine

postganglionic: acetylcholine

sympathetic neurotransmitters

preganglionic: acetylcholine

postganglionic: norepinephrine

preganglionic

neuron that synapses at ganglion

postganglionic

neuron that reaches organ

parasympathetic ganglia

not in a chain; located closer to target organ

sympathetic ganglia

in a chain; near spinal cord