3: SIGNALS Flashcards
electrical charge across a cell membrane (diff in charge inside + outside cell)
MEMBRANE POTENTIAL
2 TYPES OF MEMBRANE POTENTIALS THAT AXONS HAVE
- RESTING MEMBRANE POTENTIAL
- ACTION POTENTIAL
membrane potential of a neuron when it is AT REST (not being altered by excitatory/inhibitory postynaptic potentials)
RESTING MEMBRANE POTENTIAL
brief electrical impulse that provides basis for conduction of info along axon
ACTION POTENTIAL
2 WAYS MEMBRANE POTENTIAL CAN CHANGE
- HYPERPOLARIZATION
- DEPOLARIZATION
incr in membrane potential of cell relative to normal resting potential (inside axon become more NEGATIVE than outside)
HYPERPOLARIZATION
reduction (toward 0) of membrane potential of a cell from its normal resting potential (inside of axon becomes more POSITIVE than outside)
DEPOLARIZATION
value of the membrane potential that must be reached to produce an ACTION POTENTIAL
THRESHOLD OF EXCITATION
VALUE OF RESTING POTENTIAL
-70 mV
VALUE OF THRESHOLD OF EXCITATION
-55 mV
VALUE OF ACTION POTENTIAL
+40 mV
VALUE OF HYPERPOLARIZED NEURON
-90 mV
movement of molecules from regions of HIGH concentration to regions of LOW conentration
DIFFUSION GRADIENT
substances that split into 2 particles w opposing electrical charge when dissolved in water
ELECTROLYTES
notion that oppositely charged atoms attract + alike atoms repel = due to ____
ELECTROSTATIC PRESSURE
notion that CATIONS (+) + ANIONS (-) move towards areas of unlike charge (away from highly +/- areas)
ELECTROSTATIC GRADIENT
notion that gradients can balance one another + this is maintained by SODIUM-POTASSIUM PUMP
DYNAMIC EQUILIBRIUM
pump that pushes SODIUM ions out of axon in exchange for POTASSIUM ions
SODIUM-POTASSIUM PUMP
fluid within cell
INTRACELLULAR FLUID
fluid outside cell
EXTRACELLULAR FLUID
charge INSIDE cell = more ____
NEGATIVE (MORE ANIONS)
charge OUTSIDE cell = more ____
POSITIVE (MORE CATIONS)
IONS INSIDE CELL:
LOW concentration of ___ + ___
HIGH concentration of ___ + ___
LOW: Cl- + Na+
HIGH: K+ + A-
IONS OUTSIDE CELL:
LOW concentration of ___ + ___
HIGH concentration of ___ + ___
LOW: K+
HIGH: Cl- + Na+
