L5 Biopotentials Flashcards
What are the 4 types of ion channels?
-Leakage ( nongated channels )
-Ligand gated channels
-Voltage gated channels
-Mechanically gated ion channels
Resting membrane potential is a ___________ across the resting cell membrane.
constant potential difference
What are the properties of resting membrane potential?
- It is constant and stable
- Negative inside compared to the outside
- Different in different cells
What are the genesis of resting membrane potential?
- Permeability of the membrane Na+ and K+
- Action of sodium-potassium pump
- Negatively charged proteins in the ICF
Excitability refers to an ability of a _____ to recieve _____ and _______ to that stimuli.
tissue
stimuli
respond
Action potential is the _________ which occur in the ______ following ____.
brief sequence of changes
membrane potential
excitation
What are the phases of action potential?
Stimulus artifact
Latent period
Depolarization
Repolarization
Hyperpolarization
Stimulus artifact is when there is a _________ of the base line where the _______ is applied. This is due to the ______ from the stimulating site.
brief irregular deflection
point of stimulus
current leakage
Latent period is the _____ for the ____ to travel from the site of ____ to the _____ electrode.
time taken
impulse
stimulation
recording
Depolarization is the ______ of voltage gated ____channels.
opening
Na+
Explain what happens during depolarization?
-when membrane potential exceeds the threshold limit, the voltage gated Na+ channels open
-results in massive influx of Na+
-potential overshoot and reach spike potential
-Na+ gated channels close.
Repolarization is the _____ of voltage gated ____ channels.
opening
K+
Explain what happens during repolarization?
-opening of voltage gated K+ channels
-results in efflux of K+
-causes a net transfer of positive charge out of the cell
-as it approaches towards resting state, it becomes slow.
Hyperpolarization is when the membrane potential reaches _______, most of the K+ gate channels are ____ but some are ___.
As a result, the potential becomes more _____. After all of the K+ gated channels are closed, some ______ become ___ to restore the RMP.
resting state
closed
open
Na+/K+
active
What are the properties of action potential?
Threshold stimulus
All or None Law
Refractory period
Conduction
Accommodation
Threshold stimulus is the ______ quantity of _______ required to intiate _____.
minimum
stimulus
action potential
Rheobase is the _____ ______ stimulus which when applied for a prolonged time will produce ____.
minimum voltage
action potential
Utilization time is the ______ ______ that a current _____ to rheobase must act to induce ______.
minimum time
equal
action potential
Chronaxie is the _____ ____ for which a stimulus ______ the _____ value has to be applied in order to start an ______.
minimum duration
twice
rheobase
action potential
Refractory period is the period of ____ during which a ____ can not ______ another ____.
time
neuron
generate
action potential
Absolute refractory period is when even a ____ stimulus will ____ generate another action potential
very strong
not
Relative refractory period is when a _____ stimulus can initiates another action potential.
suprathreshold
Conduction is where action potential is conducted as a _________. It is _____ in nature.
wave of depolarization
self propagating
Accommodation is when the stimulus is applied constantly for a ____duration, the site of the application of stimulus ____ to produce _______.
prolonged
fails
action potential
