electrical signals of neurons Flashcards
membrane potential
result from ionic concentration differences across two membranes and permeability of membrane
high concentration of ________outside and high concentration of _________inside
Na+ and Cl-
K+ and negative protiens
steep concentration gradienet from _____ to __________ of cell for Na and opposite for K
outside to inside
leak ion channels
always open and responsible for permeability at rest
more K and Cl channels
specific for one type
intracellular and extracellular fluid are electrically
neutral
potential difference
electrical charge difference across membrane
-70 to -90 mV
membrane most permeable to
K+; due to many leak channels
resting membrane potential maintained by
NaK pump
depolrization
inside of cell becomes more positive, closer to zero
most common way from na diffusing into cell down concentration gradient
Ca role in Na gates
low extracellular Ca causes voltage gated channels to open, causing Na to flow in causing AP
Ca functions (3)
- depolarizes cardiac cells
- affects Na voltage gates
- regulates NT release at synaptic vesicles
Hyperpolarization
inside of cell becomes more negative
farther away from zero and AP
most commonly caused by K diffusing out of cell
if K stays inside cell
depolarization happens
Chlorine into cell causes
hyperpolarzation
causes cell to get more negative
primary causes of hyperpolarization
K+ exit and Cl- entry
