Lecture 9: Division of Labor

What is a ganglia/ganglion?

knotlike swelling in a nerve where the cell bodies of peripheral neurons are concentrated

"tiny brain of worms"

what are tracts of neurons?

bundled/cabeled neurons in the CNS going to same destination

what are nerves?

bundled axons in the PNS

what are afferent nerves?

sensory, transmit information from environment and PNS to CNS

What are motor neurons?

neurons that carry outgoing information from the brain and spinal cord (CNS) to the muscles and glands (PNS)

what are interneurons?

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

What are cranial nerves?

12 types, extend from brain to face, shoulder, and head

vagas nerve goes to organs

transmit motor and sensory info

what are spinal nerves?

extend from spinal cord to all parts of the body

what is a dermatome

specific segment of skin supplied by a single spinal nerve

can PNS nerves and CNS tracts regrow?

nerves can, neurons in the CNS cannot

what is the somatic nervous system?

PNS, controls voluntary movement

What is the autonomic nervous system?

PNS, controls involuntary functions like breathing and heart rate

what are the subdivisions of the autonomic nervous system?

sympathetic and parasympathetic

What does the sympathetic nervous system do?

fight or flight response, increases heart rate and blood flow

in the thoracic and lumbar nerves

has short preganglia fibers and long post ganglia fibers

What does the parasympathetic nervous system do?

rest and digest, reestablishes baseline functions

in cranial and sacral nerves

long pre ganglia fibers, short postganglia fibers

What does rostral mean?

toward the forehead, toward the nose

what does anterior mean

front, towards the mouth

what does dorsal mean

top or back, towards the back

what does ventral mean

toward the bottom or chest, lower, towards the stomach

what deos proximal mean ?

near the CNS

what does distal mean?

far from the CNS

what does medial mean?

toward the center

what does posterior mean?

toward the tail

what does superior mean?

toward the head

what is the brain stem made of?

midbrain (cerebellum), pons, medulla oblongata

what does caudal mean?

Toward the tail

how do dermatomes help doctors?

each patch of skin corresponds to a spinal nerve, so helps determine what part of the spinal cord is injured

what nervous systems act as a seesaw?

sympathetic and parasympathetic nervous systems

How many pairs of spinal nerves are there?

31