Chapter 12 HW A&P - Mills

Nuclei

collections of nerve cell bodies in the CNS

Ganglia

collection of nerve cell bodies outside of the CNS

Cardiac Muscle

effector of the autonomic nervous system

effector neurons

from CNS to the effectors

CNS myelin sheath

oligodendrocytes

astrocytes

between capillaries and neurons

somatic NS

voluntary regulation

monitoring of GI tract contractions

enteric nervous system

nissl bodies

rough ER at the nerve cell body

synaptic vesicles

storage of neurotransmitters

one

number of axons leaving nerve cell body

trigger zone

location for initiating an axonal impulse

schwann cells

myelin sheath in the PNS

nodes of raniver

gaps in the myelin sheath

axon

conducts impulse away from nerve cell body

afferent nerves

sensory neurons

absolute refractory period

a second impulse cannot be initiated

depolarization

sodium ions float into cell

rapid impulse conduction

function of myelin sheath

repolarization

potassium ions flow from cell

neurotransmitter

bind to receptors on post-synaptic cell

hyperpolarization

membrane potential (-70mV —> -80mV)

excitory neurotransmitter

membrane potential (-70mV —> -60mV)

agonist

enhances ation of neurotransmitter

glutamate

excitatory CNS neurotransmitter

parkinson’s disease

degeneration of dopamine axons/cells

Wallerian degeneration

loss of distal end of severed neuron

chemically activated ion channels

neurotransmitters

Na+, K+, ATPase

ion balance inside and outside of cell

membrane threshold at synapse

activates voltage gated channels (Na+&K+etc)

Membrane polarity maintenance

K+& Na+ leak channels

Agonist

Binds to receptor and turns it on

Antagonist

Turns off the receptor