electrical activity of neural pathways Flashcards
how are neurons able to respond to various stimuli
by altering electrical charge across their membran
Interior of cell has a relative negative net charge in
comparison to outside of the cell due to ______________
due to ionic composition of
cytoplasm vs extracellular fluid
what is the membrane potential for the equilibrium potential for K+(Ek+)
-90mV
what is nernst equation
Electrical potential required to oppose movement of ion (x) across a freely permeable membrane
* Provides a measure of the chemical driving potential established by the concentration gradient for ion (x)
what is goldman equation used for
to find resting membrane potential
what is depolarization
decrease in potential and membrane less negative
what is repolarization
return to resting potential after depolarization
what is hyperpolarization
increase in potential and membrane more negative
what is gating
the transition betwen states in an ion channel
name the types of ion channels
voltage -gated
ligand-gated (extracellular ligand)
ligand gated (intracellular ligand)
mechanically gated
why is there a central porre in ion channles
so ions can diffuse
why are there polar amino acids in ion channels
for forming a selective filter
what is the absolute refractory period
A period of complete resistance to stimulation
➢ Inactivation of Na+ channels means that after an action potential there is a brief period when no other action potential can be generated
what is the relative refractory period
A period of partial resistance to stimulation
➢ Lasts as long as the K channels are open
what is contigous conduction
Conduction of action potentials in unmyelinated axons
what are c fibers
unmyelinated fibers which carry sensory info
what increases action potential speed
a wide axon
insulated axon
