Neurophysio - neurons and action potential Flashcards
atoms that have lost or gained an electron, making them positive or negative
ion
wall of a neuron should be ___, meaning some ions will pass through it
semipermeable
In ___ transport, no energy is spent by the cell to transport ions across the cell membrane
passive
In ___ transport, the cell spends energy transporting ions across the cell membrane
active
In active transport, __ __ move __ (Na+) and __ (K+) against the gradient
sodium-potassium pumps; sodium; potassium
this energy gradient is electrical charge + molecular density; essentially, oppositely attracted ions move towards each other
Electrochemical gradient
In neurons, this energy gradient causes an electric current, and can be measured by an EEG or ABR
concentration
at rest, the intracellular fluid of a neuron is ______ charged
negatively
Sodium channels opening causes the net charge inside the cell to _____. This continues throughout the ____ phase
increase; depolarization
At the end of depolarization, ____ channels start to chose and ____ channels stat to open, which causes the net cell charge to ___
sodium; potassium; drop
Name for the net charge (aka potential) across a membrane when neuron is not firing
resting membrane potential
change in electrical potential that happens when cell membrane adequately stimulated
Action Potential
FIRING NEURONS
Period of time during depolarization where no amount of stimulation will make it depolarize again
absolute refractory period
what are the five phases of action potential?
- Local signals sent
- Local signals cause threshold
- Depolarization
- Repolarization
- Hyperpolarization
period of time during repolarization and hyperpolarization where membrane can be stimulated again, but only with higher than normal levels
Relative refractory period
name, sup to inf
myelin sheath; node of ranvier
