exam 1 review questions Flashcards
Using the nerst equation, if the concentration of K+ increased by 10x outside the cell, what would happen to the equilibrium concentration?
become more positive
During the fall phase of action potentials, which is higher?
K+ conductance
During the rising phase of action potentials, which is higher?
Na+ conductance
how do we know that the rising phase of an action potential is caused by Na+ influx?
external sodium is taken out AND there are toxins to block
if the membrane potential is -65 mV, which direction would the K+ ion flow when the K+ channels are OPEN?
out of the cell
under which condition would K+ have the largest driving force?
+62 mV
* the farther you are from the equilibrium potential the higher the driving force
if delayed rectifier K+ channels didn’t exist, the membrane would…
repolarize very slowly
the ion X is negatively charged and more concentrated inside than outside the cell. therefore…
Ex is positive
in a neuron at rest
very permeable to K+ AND membrane potential is closer to K+ potential than Na+ potential
suppose a neuron was selectively permeable only to K+ ions (only K+ channels open). what would happen to the membrane potential of this cell if Na+ channels were now added to the cell and opened?
Vm would depolarized (more +)
a dendrite with which properties have the highest length constant?
HIGH membrane resistance and low internal resistance
T or F: peptide neurotransmitters are released on the same time scale as amine and amino acid transmitters?
false
- peptides are farther back
- all work through G-protein acceptors
decreasing the length constant could be done by:
increasing the number of open K+ channels
what did early scientists think was the role of the brain ventricles?
humor balance AND involved in controlling limbs
what are nissil bodies?
ribosomes (found in RER)
