Action Potential
What is the threshold voltage for an action potential
-50 mV
What will happen to the cell voltage if the K+ leak channels open
K+ will leave the cell to follow the concentration gradient and the voltage will drop.
What kind of macromolecule corresponds to neurotransmitters
Proteins
Which lobe of the brain is associated with hearing?
Temporal lobe
What is the purpose of the sodium ion leak channels
To allow the entry of sodium ions with the concentration gradient so the voltage can increase
What triggers the release of the neurotransmitter?
The entry of Ca2+ into the cell through leak channels.
What is the name for the pouch that holds the neurotransmitters
Vesicles
Which lobe of the brain is associated with impulse control and planning?
Frontal lobe
Will accept prefrontal cortex
Which phase is longer: the depolarization phase or the repolarization phase
Repolarization, since the K+ voltage gated ion channels take longer to both open and close
What is the main difference between a leak channel and a voltage gated channel?
Leak channels are sensitive to stimuli and voltage gated channels are more sensitive to voltage.
What (besides the entry of Ca2+ into the cell) makes the release of neurotransmitters possible?
The fusing of the vesicle with the cell membrane.
Which part of the brain is the medulla oblongata located in?
Hind brain
Why does the voltage drop below -70 mV during the repolarization phase
Since K+ ions are leaving the cell, and since the K+ voltage channels close so slowly, the voltage drops below negative 70 mV
What voltages are required to open or close a K+ voltage gated channel?
In order to open the channel, you need a voltage of +30 mV. In order to close, you need to reach a voltage of -90 mV
What happens when the neurotransmitter binds to the neurotransmitters
name two possible answers
Receptor could activate Na+ leak channel, starting action potential
Receptor could activate K+ leak channel, stopping the action potential
What does the medulla oblongata regulate?
Controls beathing
Why does the action potential flatten when there is both a K+ and Ca2+ voltage gated channels opening at the same time
Hint: there is more K+ inside the cells than outside
Hint 2: there is more Ca+ outside than inside the cell
The voltage drop created by the K+ is counteracted by the Ca2+ generated voltage increase.
During which phases of the action potential are the slopes positive?
#1 reaching the threshold voltage
#2 during depolarization (-50 mV to 30 mV)
#3 regaining the resting cell voltage after reaching a voltage of -90 mV
If you took a Ca+ channel blocker, how would that impact chemical neurotransmission?
If Ca2+ channels are blocked Ca2+ cannot enter the cell. This means that the neurotransmitter cannot be released and the action potential cannot start in the second neuron.
Why are so many neurons able to fit so many into the brain?
A large surface area over volume ratio for the axon