nervous system (copy)

CNS

CNS

brain/spinal cord

peripheral nervous system

all parts of the nervous system external to the brain and spinal cord

autonomic nervous system

involuntary, stimuli transmitted to cardiac and smooth muscle

Myelin Sheath

allows electrical impulses to transmit quickly and efficiently along the nerve cells

neurilemma

protects neuron and regenerates nerves

neuroglia

nerve glue, provide developmental, physiological, and metabolic support for neurons

nerve impulse

neurons are not connected, travels down the axon membrane as an electrical action potential to the axon terminal

spinal cord

2 main functions- conducts impulses to and from brain, reflex center

efferent nerves

motor transmitters that carry impulses from the central nervous stem out to the muscles and glands

afferent

sensory transmitters that sends impulses from receptors in the skin, muscles, and joints to the CNS

repolarization

is the re-establishment of a polarized state in the cell after depolarization

polarized

when inside of a cell is more negatively charged than the outside it is…

refractory period

is the time between the completion of the action potential and repolarization

somatic reflexes

are involuntary stimuli transmitted to skeletal muscles from neural arcs in the spinal cord

depolarized

is more positively charged on the inside than the outside

salutary conduction

an action potential that rapidly skips from node to node on myelinated neurons is experiencing…

3 special characteristics of a neuron cell

lives long, amitotic, high metabolic rate

astrocyte (CNS)

most abundant CNS

microglial (CNS)

change into macrophages-defenders, first to respond when something goes wrong in the brain

ependymal (CNS)

separate the CNS interstitial fluid and cerebrospinal fluid

oligodendrocytes (CNS)

myelinating cells of the central nervous system

satellite cells (PNS)

surrounds neuron cell bodies in PNS

Schwann cell

wraps PNS fibers to form myelin sheath

sympathetic

fight/flight

parasympathetic

rest/digest

sensory

somatic/visceral, afferent

motor

muscle/glands, efferent

Na+ and K+ closed

#5 - explain which ion channels are open or closed

trigger for Na+ to open

threshold - explain which ion channels are open or closed

Na+ open, K+ close

#2 - explain which ion channels are open or closed

Na+ close, K+ open

#3 - explain which ion channels are open or closed

K+ closing, Na+ reset

#4 - explain which ion channels are open or closed