Nervous System Flashcards
The nervous system is ___, __ and involves ___ signalling
fast, specific, direct
Neurons cannot ___ and use ___ as an energy storage
reproduce, glucose
structures that receive electrical signals
dendrites
where action potentials are initiated; where soma and axon meet
axon hillock
tranduce signals
axons
substance that forms a sheath around some axons; enhances the speed of propagation
myelin sheath
In a myelinated axon, the myelin acts as an ____, which means the ___ only occurs at the ___ ___ ____ making the electrical signal faster.
insulator, depolarization, nodes of ranvier
A _____ diameter of neuron means faster action potential because of less ____
larger, resistance
Cells that produce the myelin sheath in the CNS
oligodendrocytes
Cells that produce myelin sheath in the PNS
schwann cells
support cells of the nervous that are capable of dividing
glial cells
glial cells that provide immune function in the NS
microglia
glial cells that circulate the CSF using cilia for nourishment
ependymal cells
Glial cells that support function of PNS
satellite cells
glial cells that provide nutrient balance in the CNS using the BBB
astrocytes
channels that open and close in response to a change in electric membrane potential
voltage gated channel
a channel that opens and closes in responses to a molecule binding to a ligand binding site
ligand gated channel
channel that opens and closes in response to physical changes around the channel
mechanically gated channel
Na+ channels are ___ ____ channels and can be ___
fast voltage-gated
K+ channels can be ____ and there is another type that is ___ and allows for ____ transport of K+ to the outside
voltage-gated, leaky, passive
The Na+/K+ ATPase continuously pumps ___ Na+ out for every ___ K+ in. It requires ___
3, 2, ATP
action potential threshold
-55 mV
Absolute refractory period results in __ __ to additional stimuli because the cell is already ___ or the voltage gated ____ channels are deactivated while the cell is repolarizing
no response, depolarizing, sodium
Relative refractory period a very ____ stimulus can trigger an action potential and this is during the -__ stage
large, hyperpolarization
When ions move between cells through gap junctions to transmit APs; rapid
electrical transmission
when APs release NTs that bind to adjacent neurons or cells to send a signal
chemical transmission
The AP activates ____ ____ ___ Influx of Ca2+ causes presynaptic neuron to release ___
voltage-gated Ca2+ channels, vesicles
postsynaptic membrane depolarizes by opening Na+ gates
EPSP
Post synaptic membrane hyperpolarizes by opening K+ gates
IPSP
ACh is released at __ __ for muscle contraction (excitatory). ACh is ____ or broken down by ____ ____, on the postsynaptic membrane. This is a hydrolysis reaction that produces __, which is diffused away and ____ which undergoes reuptake to be used again as ACh
neuromuscular junction, hydrolyzed, enzyme acetylcholinesterase, acetate, choline
___, _____ and ____ are amino acid transmitters. The first is excitatory, the second is inhibitory in the ___, and the third is inhibitory in the __ __
glutatmate, gaba, glycine, brain, spinal cord
Amino acid derived NTs include __ and ___ which are released in the ANS, and ___ and ___ which are released in the brain
norepinephrine, epinephrine, serotonin, dopamine
___ ____ is a NT that is not stored in vesicles for release. Instead it is synthesized __ __. It relaxes __ __ and causes ____ which increases blood flow
nitric oxide, on demand, smooth muscle, vasodilation
Neuropeptides are short amino acid chains like ___ and substance P, which play a role in ____ perception
endorphins, pain
