Wk 4 Nerve Physiology Flashcards
A cell has a difference in charge across its membrane; more positive on the outside than inside
Is this true?
Yassssss
When a neutron is not stimulated, what is it called?
A resting cell and is polarised
Na+ ions are concentrated on the ……
Outside of a membrane
Negatively charged ions, K+ ions and proteins are on the ……
Inside of a membrane
Neurones and muscle cells rely on 4 types of ion channels, what are they? And when do they open/close
Leakage channels- the gates randomly alternate between open and close positions (sameeeee)
Chemical gated channels- open and close in response to a specific chemical / ligand stimulus
Voltage gated channels- open in response to a change in membrane potential (voltage). Participate in generation and conductance of aps
Mechanically gated channels- open and close in response to a mechanical stimulation in form of vibration ( sound waves) pressure (touch) or tissue stretching.
Tell me bout polarised state
WELL
the outside is more positive than inside
That sounds a bit depressing, doesn’t it?
Where is the Na+/K+ pump located and what it do
It’s located in the glorious cell membrane
It corrects the imbalance of ions across cell membrane by pumping a bit of 3Na+ ions out while pumping 2K+ ions in.
And it uses energy from ATP for the active transport of ions (against their concentration gradients)
What’s it called when a nerve is stimulated and the resting potential changes
A nerve impulse
Examples of such stimuli are pressure, electricity, chemicals. Ect.
What does action potential mean?
Is the rapid change in polarity that moves along the nerve fibre
The moving change in polarity has a bunch of different stages, name 3 pls
Depolarisation ⬆️
Re polarisation ⬇️
And refractory phase ⬇️⬇️
Action potential is when the membrane potential (ie the charge difference) changes and so does the balance
True or false
TRU
Net balance changes from -__ to +__ mV
-70 mV to +30mV
And it’s gotta go back again - the signal that makes this occur is action potential.
What’s it’s called when the action potential spreads along the axon membrane???
It’s called a continuous propagation.
Nerve impulse also known as AP is propagated along a nerve process. (Dendrite or axon )
Which one can transmit an AP and what one can only generate (start) one?
A dendrite can transmit an AP
but and axon can only start one.
____________ is a short period of time during which the nerve cell membrane can’t be depolarised;sodium gates cannot be opened again until the membrane is repolarised to its normal resting potential (basically can’t do shit)
Refractory phase
