Neuro Flashcards
(54 cards)
transmitters: excitatory: moves the post-synaptic membrane ____ to threshold (aka ____) , uses _____ to do so
closer to threshold
aka depolarization
Na-K channels to do so
transmitters: inhibitory: moves post-synaptic membrane ____ from threshold (aka _____), uses _____ to do so
away from threshold
aka hyperpolarization
Cl- channels to do so
what are the 6 excitatory transmitters?
Ach, 5HT (serotonin), NorEpi, Epi, Dopamine, Glutamate
what are the 2 inhibitory transmitters?
Glycine and GABA
what are subgroups of neuropeptides? what do they do? what are the 3 specific kinds?
pain sensation and perception neuromodulators and neurohormones (modify the work of other NTs) 1. substance P 2. endorphins 3. enkelphans
refractory period: absolute vs relative
absolute: closure of inact. gates for Na+ will NOT open till the cell is FULLY repolarized (-70mV)
- takes up most of the curve
relative: starts when absolute is over and lasts through hyperpol.
there CAN be axn potential IF there is a big enough stimulus to bring it from more neg. status back to threshold
what is accomodation?
when the threshold is passed but no axn potential is produced. (when depol. closes Na+ channel inactivation gates…which can’t reopen till threshold of -70mV is achieved).
example: hyperkalemia: too much K+ = decreased drive inside cell, can’t get back to -70mV…. gates wont open = cardiac arrest
bigger nerve = faster or slower impulse?
myelination = faster or slower impulse?
bigger and myelin both conduct a faster impulse current
what are the nodes of ranvier?
breaks in myelin where axn potential is generated
how do gap junctions assist in electrical synaptic transmission ? what type of cells are these in?
allow signal to go straight through = faster impulse
these are in coordinated muscle cells: ventricles (cardiac) and uterus + bladder (smooth)
what are chemical synaptic transmitters?
inhibit or excite dependent on the NTs
what is the process that occurs at a synaptic junction of a motoneuron after the axn potential comes into the pre-synaptic terminal?
- ca+ channels open
- flow down conc gradient, synaptic vessels open and release NTs
- diffuse across cleft and bind receptors on the end plate
=change in membrane potential
somatic vs autonomic
both of the peripheral nervous system …
somatic: voluntary movements and involuntary reflexes- sensory and motor to the body
autonomic: viscera, smooth muscle, and glands
electroneutrality
MACROscopic neutrality
inside and outside the sell there is a balance of total pos and neg charge (cations and anions)
membrane potential is created by what type of movement?
MICROscopic movement of charged particles (Na+, K+, Ca+, Cl-, HCO3-)
what is resting membrane potential? what are freely diffusing here? what is the Na/K pump doing?
period of time when excitable cells are NOT transmitting signals
K+ and Cl- freely diffusing
Na/K ATPase pump 3Na+ out and 2K+ in = negative inside cell
if there is a potential difference across the membrane, there will be a changed rate of diffusion of ____
charged solute
if there is no potential difference across the membrane, the diffusion of ____ will do what?
charge solute
will create a diffusion potential
conc. of solute does or does not change w/ movement of ions across the membrane
DOES NOT
what are our types of excitable tissue?
nerves and muscles
changes in membrane potential will cause axn potential (depol to repol)
what does our glandular tissue do with a change in membrane potential?
hormones secretion and other functions
____brings opposites closer together and ____ brings opposites farther apart
depolarization
repolarization
what is it when the potential or MORE neg. than the resting membrane potential?
hyperpolarization
axon vs dendrite
axon: away from the cell
dendrite: toward the cell
