L10: Neurobiology IV Flashcards
major cation in intracellular fluid
K+
major cation in extracellular fluid
NA+
major anion in intracellular fluid
phosphate ions and negatively charged proteins
major anion in extracellular fluid
Cl-
intracellular fluid is slightly
negative
extracellular fluid is slightly
positive
the two compartments exist in a state of
electrical disequilibrium
to generate a membrane potential difference
active transporter is inserted into the membrane
transporter ___ to move a positive ion out of the cell against it’s concentration gradient
uses energy
the combination of electrical and concentration gradients
electrochemical gradient
resting membrane potential
electrical gradient between the extra and intra cellular fluids
the membrane potential that exactly opposes the concentration gradient of the ion is known as
equilibrium potential
Nernst equation
Eion = 61/z * log(ion(out)/ion(in))
the greater the membrane permeability to an ion species,
the greater the contribution that ion species will make to the membrane potential
pump moves
3 Na+ out of the cell and 2 K+ in
pump
maintains the concentration gradients down which the ions diffuse to produce the charge separation
graded potentials generally occur
in the dendrites and cell bodies
absolute refractory period occurs
when voltage-gated Na+ channels are open or have proceeded to the inactivated state
what follows the absolute refractory period?
relative refractory period
graded potentials
variable in terms of amplitude and duration and are conducted decrementally
action potential
a rapid change in the membrane potential with rapid depolarization and repolarization
action potentials starts at
trigger zone
