Exam 2: Action Potentials Continued Flashcards
When the cell is hyperpolarized, does it take more or less stimulus to turn the cell back on?
More
T/F If sodium channels don’t reset, they can still be used
False; they need to be reset to be used again
During depolarization, what are the two important factors seen in the Goldman equation?
- Concentration gradients for ions
- Permeability for ions
T/F Chloride is found in the nervous system and hyperpolarizes/suppresses electroactivity
True
What occurs in GABA receptors?
GABA receptors open up chloride channels in neurons which allows chloride to flood in and make the cell more negative
How many binding sites does acetylcholine have?
2
What connects the neurotransmitter to a neurotransmitter receptor?
Neuromuscular junction
Where are nicotinic acetyl choline receptors found?
Skeletal muscles and brain
Do both binding sites for Ach have to be occupied to allow current to run through it?
Yes
What is a nicotinic acetyl-choline receptor? (nACh)
Donut shape protein in the cell wall that is lined w/ amino acids that have a negative electrical charge; the negative charge repels negatively charged electrolytes from moving through the channel
Which electrolyte easily gets through nACh receptors?
Sodium; majority of the current that goes through is sodium b/c it is the easiest to get through since it moves down its concentration gradient
How is potassium prevented from leaking out of the cell?
Sodium wants to flow in so badly that it prevents the potassium from leaking
Which other ion can move into the cell to also depolarize it?
Calcium
Why doesn’t calcium just flow into the cell?
Because it is large and “clunky” per Schmidt
Describe how a neuron talks to skeletal mm.
A motor neuron is connected to skeletal muscles via the NMJ (neuromuscular junction), where ACh (neurotransmitter) is released to bind to 2 sites on the receptor. Once ACh binds, this causes an action potential to spread along the muscle fiber on both sides and signals to the muscle to contract and move.