Generation of the AP and transmission of impulses Flashcards
Ions cross the membrane via channels or pumps that are formed by ____ in the membrane.
proteins
Ion ___:
- actively move ions AGAINST the concentration gradient
- creates ion concentration gradients
Transporters
Ion ___:
- allows ions to diffuse down the concentration gradient
- causes selective permeability to certain ions
channels
Type of channel:
- The channel opens when a substance binds to a receptor
- involves a protein or receptor attached to either the extracellular or intracellular portion of the membrane
- SELECTIVE
ligand gated channel
Ach at the NMJ is an example of a ____ gated channel.
ligand
Type of channel:
- opens when a membrane voltage reaches a certain value
- SELECTIVE
voltage gated channel
(true/false) Voltage gated channels have different voltages to change the permeability of the membrane depending on the channel.
True
Type of channel:
- allows ions to flow dependent on stretch, pressure, and temperature
- SENSORY receptor involvement (hair follicle)
mechanically gated channel
Potassium (K+) is greater on the (inside/outside) of the cell
inside
Sodium (Na+) is greater on the (inside/outside) of the cell
outside
Chloride (Cl-) is greater on the (inside/outside) of the cell
outside
Organic anions (-) are greater on the (inside/outside) of the cell
inside
Potassium (K+) wants to go (in/out) of the cell
out
Sodium (Na+) wants to go (in/out) of the cell
in
Chloride (Cl-) wants to go (in/out) of the cell
in
(true/false) Organic anions cannot move along a diffusional gradient because they cannot pass through a membrane or channel
true
Normally, a neuron is more (negative/positive) compared to its extracellular component.
negative
The membrane potential at which electrical forces equally counter the diffusional forces
equilibrium potential
Membrane potential for Potassium is ___ mV.
-75
Membrane potential for sodium is ___ mV.
55
The sodium potassium pump transfers __ Na+ into the EXTRACELLULAR space while ___ K+ is transported to the INTRACELLULAR space.
3, 2
What is the resting membrane potential?
-65 to -75
A rapid change in membrane potential
action potential
Where is an action potential initiated?
axon hillock
Non-myelinated axons have (slow/fast) conduction
slow
(True/false) The diameter of an axon is a factor in how quickly an impulse travels.
True
A larger diameter of an axon results in a (slower/faster) transmission of an impulse
faster
(true/false) When myelin is disrupted with disease, transmission of impulses are delayed or absent with loss or poor timing of information.
true
When damage to an axon/myelin occurs, re-myelination MAY occur but the nodes are now ___ together causing a (slower/faster) transmission of impulses
closer, slower
Low sodium
hyponatremia
An increase in sodium causes ____ and ___ in cells.
swelling, demyelination
Low calcium
hypokalemia
Electrolyte that stabilizes voltage gated channels
calcium
hypokalemia will cause ___ of the nervous system.
excitement
A decrease in ___ causes weakness.
potassium
What toxins inhibits/blocks sodium channels?
tetrodotoxin, saxotoxin
