• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/116

Click to flip

116 Cards in this Set

  • Front
  • Back
the net charge within the cell is ?
negative @ -70mV
what ion has the highest relative conductivity?
K+ potassium @ 1.00
what ion has the lowest relative conductivity?
Na+ @ 0.04
what are the 2 forces that wish to cause an ion to move?
electrical
concentration
Sodium has a tendency to move _____ of the cell?
into
In terms in concentration K+ wishes to move _____ of cell and in terms of electrical it wishes to move _____ of cell
out
into
what is the membrane potential @ which K+/potassium is @ equilibrium?
-94mV
If concentration remains the same, and K+ mV rises from equilibrium to -70mV, what is the driving force and net result?
Potassium seeks to move out of cell @ 24 mV because the electric pull is too weak to compete with the concentration gradient
what is the driving force (mV) of sodium?
140mV inward
what is the driving force of chloride?
45mV outward
permeability x driving force =
J: Flux
Potassium (K+):
Permeability =
Driving force =
High (permeability)
Low (driving force)
Sodium (Na+):
Permeability =
Driving force =
Low (permeability)
High (driving force)
what determines the net flux of sodium and potassium in the cell and what is it?
Sodium-Potassium pump transporters
3/2 : Na+/K+ therefore Na+ = 50% more
the membrane potential of a cell will always resemble most closely to what?
the most permeable ion
the Goldman equation reveals that by the 3 most important ions, the resting membrane potential for a neuron = ?
-65mV
what is a poison to the 3/2 sodium potassium pump?
ouabain
the cell much reach what in order to depolarize?
threshhold
the peak of 'overshoot' during APs is @ what mV?
+30 mV
the period when the action potential is repolarizing below resting membran potential =
absolute refractory period
the period of time when the mV of the neuron is more negative than resting potential thus making ensuing APs less likely
Relative Refractory Period
what accounts for the predominance of sodium influx into the cell relative to potassium and the afterhyperpolarization period?
Slow opening and closing K+ channels
At rest:
Sodium inactivation gate:
Sodium activation gate:
Potassium gate:
Potassium channel (ungated):
open
closed
closed
always open
At Depolarization threshold:
Sodium inactivation gate:
Sodium activation gate:
Potassium gate:
open
open
opening slowly
During repolarization phase:
Sodium inactivation gate:
Sodium activation gate:
Potassium gate:
closes
open
open ----> closing
As the mV passes below threshold in a hyperpolarized state:
Sodium inactivation gate:
Sodium activation gate:
Potassium gate:
closed
closed
open
As the mV reaches normal resting potential again:
Sodium inactivation gate:
Sodium activation gate:
Potassium gate:
open
closed
closing--->closed
what type of APs move toward cell body?
Antidromic Conduction
what type of APs move away from cell body?
Orthodromic Conduction
What 2 features attribute to increased conduction velocity?
- Increased diameter of axon
-myelination
What are the cells that myelinate the PNS?
Scwhann cells
What are the cells that myelinate the CNS?
Oligodendrocytes
about every 1-2 mm there are breaks in myelination called _____?
Nodes of Ranvier
What is the jumping of APs along a myelinated axon referred to as?
Saltatory Conduction
The absolute refractory period prevents what in saltatory conduction and what in terms of action potential frequency?
-prevents reverberating of axon in the opposite (antidromic) direction
-maximum discharge frequency @ about 400-500 impulses/sec
The maximum discharge frequency in Absolute refractory period is a feature of what?
inactivation gate being closed and eventually reopened for an AP to be possible
Vesicles being loaded with neurotransmitters is a _______ processs
ATP-dependent
What is visualized at the presynaptic terminal suggesting high activity
mitochondria
What 2 proteins are important in holding vesicle at the presynaptic density and preventing exocytosis?
Synapsin
Actin
what is the link between the action potential and the exocytosis of neurotransmitters?
Ca++ release within cell
What type of voltage gated channels found in the presynaptic terminal are crucial for exocytosis of n.t.?
N-type Ca++ channels
what poison can irreversibly block N-type Ca++ channels in the Presynapse?
w-conotoxin (shellfish)
as a AP causes Ca++ influx, the intracellular conc. is increased and binds to _____ which subsequently INACTIVATES channels
calcineurin
Calcium fxns in releasing nt-vesicle by binding to ______ which activates the complex __________
Calmodulin
Calmodulin-dependent protein kinase
(Cam-kinase II)
Cam-kinase II fxns to do what?
phosphorylate Synapsin I
Phosphorylated Synapsin I fxns to do what?
untether vesicles from actin thus enabling the vesicle to bind the presynaptic membrane for exocytosis
what ion may pass thru Ca++ N-type channels resulting in an inhibtory effect on synaptic transmission
Mg++
what fxns to dock vesicles at membrane for exocytosis?
Ca++
What inactivates Synapsin I at the Presynaptic process?
phosphatases
Caclium is brought back to original concentration via?
Calcium pump channels
What accounts for pre-/post-synaptic alignment while no action potentials are being fired>
release of quanta of neurotransmitters
as 'MEPPS'
the process of vesicular recycling in presynaptic process?
Inbudding by endocytosis
If a vesicle just recycled has not yet been reloaded with neurotransmitters, what is would suggest this structurally?
coated (clathrin)
______ describes the diffusing of NT out of the cleft after release @ synapse
washout
where can washout occur?
PNS
what prevents washout from occuring within the CNS?
glial cells that seal the synapse
what would be the effector in a Gprotein gated receptor?
Ionophore (ion channel)
The neurotransmitter serves as the _____ in a gprotein gated receptor?
ligand (ligand-gated receptors)
Which are most selective:
ligand-gated vs. voltage-gated
voltage-gated
if channels permeable to Na+ and K+ experience an EPSP, the mV will be changed how?
depolarize and average out @ about -20mV = -90 + 50
PSPs that occur simultaneously in a consecutive manner prior to the former PSP decrementing
Temporal Summation of PSPs
In the case multiple PSPs are generated simultaneously at different locations on the post synaptic terminus
Spatial Summation
action potential usually propagate at which site of a neuron?
axon hillock
an action potential is most likely to develop at a site with the ____?
lowest potential
most EPSPs are found at what aspect of neuron?
dendrites
most IPSPs are found at what aspect of neuron?
soma
Parasympathetics of the ANS are deemed ______ based on its regions of innervation
Craniosacral
what is the ratio of preganglion:postganglionic for the Sympathetics?
1:20
divergent effect
what is the ration of preganglionic:postganglionic for the Parasympathetics?
1:1
targeted
what is the primary neurotransmitter for the parasympathetic postganglionic synapse?
Ach
what is the primary neurotransmitter for the sympathetic postganglionic synapse?
NoreEpi
the Splanchnic nerve innervates the ______ to release ______ and therefore is a _______ preganglionic sympathetic axon
adrenal medulla
Epi/Nor
what is the exception for sympathetics releasing primarily NE at postganglionic terminus?
sweat glands and some blood vessels that have muscarinic receptors for Ach
what are the main inhibitory NT in the CNS?
GABA (gamma amino butyric acid)
ionotropic form
what is the main inhibitory NT in the PNS?
glycine
Ach is synthesized by ______?
Choline Acetyltransferase (ChAT)
how does the presynaptic cell deal with the scarcity of choline?
50% recycled via sodium driven reuptakes channels
Ach depletion results due to _____ targeting the ChAT converting enzyme which decreased Ach synthesis
Napthylvinal pyridine
causes the releasing of vesicles depleting the number for further use at synapse
Beta-bungarotoxin
BWSV (black widow spider venom)
toxin resulting in few Ach vesicles being released
botulinum toxin
what toxin act on the reuptake transporter for choline on the presynaptic process causing Ach depletion
hemicholinium
what acts on AchR reversibly prolonging Ach transmission
neostigmine
physostigmine
what acts on AchR irreversibly prolongin Ach transmission
malathion
Ach
Nicotine
Carbachol
nicotinic agonists
Muscarine
Pilocarpine
Oxotremorine
muscarinic agonists
Curare
Succinyl Choline
Rabies virus
nicotinic antagonists
Atropine
Scopolamine
muscarinic antagonists
what is the typical effector for nicotinic receptors?
Na+/K+ channels
what are the typical effetor for muscarinic receptors?
G-protein coupled mechanism
- inhibit adenyl cyclase
- stimulate guanylate cyclase
-stimulate phosholipase C
- alter ion channels (via cAMP)
DA, NE, EPi are all ?
catecholamines and thus derived from L-tyrosine
what converts L-DOPA to Dopamine?
DOPA Decarboxylase
what converts Dopamine to NE?
Dopamine -Beta- Hydroxylase
what converts NE to Epi?
Phenylethanolamine-N-methyl transferase
will displace catecholamine NT from vesicles causing an initial release which further depletes NT release in the future?
amphetamines
gamma-hydroxyl-butyrate for DA
enhances EPi release from adrenal medulla?
cortisol
acts on the reuptake channels for NE and thus initially leaves it in channels longer, w/ long term depletion
cocaine
depletes NE into vesicles and thus has long lasting depletion of NE release
Reserpine
what %of NE is reuptaken into the presynaptic process?
80%
what is the end product of NE/EPi catabolism?
VMA Vanillylmandelic acid
what is the end product of DA catabolism?
HVA Homovanillic acid
what are the two enxymes involved in catecholamine catabolism?
MAO - monoamine oxidase
COMT - Catechol-O-Methyl Transferase
how doe the body rid of HVA and VMA?
urine excretion
what catabolic enzyme for catecholamines is found on the mitochondrial membrane?
MAO
MAO inhibitors would tend to ______ storage of NT in terminals in regards to vesicle formation
increase
tropoline is a ?
COMT inhibitor
pargyline is a?
MAOI
where is the source of most of the adrenergic neurons in the CNS?
Locus Ceruleus
where is the source of most of the dopaminergic neurons in the CNS?
Substantia Nigra
_____% of dopaminergic neurons travel to the Corupus striatum via the ______ tract
80%
Niagrostriatal tract
_____ is an analog of the drug Meperdine and will cause degeneration of the Niagrostriatal tract
MPTP
What are the Dopamine receptor subtypes that utilize Adenyl cyclase to increase cAMP?
D1/D5
Ephedrin
Methoxamine
Clonidine
adrenergic alpha receptor agonists
Phenoxybensamine
Phentolamine
Yohimbine
adrenergic alpha receptor antagonists
Phenoxybensamine - both
Phentolamine - alpha 1
Yohimbine - alpha 2
Isoproterenol
Dobutamine
Albuterol
adrenergic beta receptor agonists
Isoproterenol - both
Dobutamine - beta 1
Albuterol - beta 2
Propranolol
Atenolol
adrenergic beta receptor antagonists
alpha 2 adrenergic receptors have what sort of activity on the postsynaptic process?
inhibitory effect