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)
which of the following is FALSE about axons?
always short and form local synapses
what did aristotle believe about the brain?
cooled the blood
T or F: broca believed that most parts of the brain shared functions
FALSE
which of the following is FALSE about gap junctions?
no synaptic integration occurs at these
