A&P Test 2 Flashcards
What is the process that the body uses to suppress activity in the body?
Hyperpolarization
It requires more of a _______ to turn on a cell that is hyperpolarized.
stimulus, or positive charge
What is another name for a voltage gated calcium channel?
a slow calcium channel
What is an example of a voltage gated calcium channel antagonist?
Dihydropyridine drugs
Chloride plays an important role in the
nervous system
Typically, chloride permeability is adjusted to ___________ electrolytes.
Hyperpolarize, or suppress
What receptors in the body open up chloride channels in neurons?
GABA
Depolarization in cells are a type of
positive feed back
Depolarization is a ________ and therefore can go in either direction
2 way process
What is the fastest way to depolarize a cell?
starting in the middle and going around in opposite directions.
What are three examples of stimulation of a cell?
Through neurotransmitters
Through direct muscle stimulation (like a taser)
Through pressure
What are the neurons called that are specialized to talk to skeletal muscles?
Motor neurons
What are two examples of neurotransmitters?
mACh
nACh
What is nACh-R?
nicotinic acetylcholine receptor
What is the space called between a motor neuron and a skeletal cell?
Neuro muscular junction
nACh has how many binding sites?
2
nACh receptors are specialized for
skeletal muscles
some are found in the brain though
How does nicotine affect a nACH-r?
Nicotine can bind and stimulate nACh receptors, producing tremors or shaking.
What is the target that’s found on skeletal muscle?
nACh receptors
What dictates the nACh receptor’s specificity?
negatively charged amino acids that line the inside of the channel
What is the most common electrolyte that is found going through a nACh receptor?
Na+
What is the process when the brain wants to move a muscle?
- Brain sends neurotransmitter nACh down neurons to the skeletal muscle.
- nACh binds to nACh receptors on the skeletal muscles.
- Receptor opens up and allows a lot of Na+ and a little Ca++ into the cell as well as a tiny bit of K+ out of the cell
- Influx of positive ions creates a depolarization, which leads to a chain reaction by activating Fast Na+ channels.
- This allows more Na+ into the cell until muscle contracts.
What is usually the initiating event for an action potential in a skeletal muscle?
- Brain sends neurotransmitter nACh down neurons to the skeletal muscle.
- nACh binds to nACh receptors on the skeletal muscles.
- Receptor opens up and allows a lot of Na+ and a little Ca++ into the cell as well as a tiny bit of K+ out of the cell
The influx of Na+ is the initiating event
Where to paralytics work?
at the NMJ
What is mACh?
muscarinic ACh
Why is mACh called that?
because it corresponds to a compound called muscarine.
What is muscarine?
a chemical that is found in the rainforest
Where are mACh receptors found?
heart
smooth muscle
lungs
What do mACh receptors do in the heart?
They adjust pumping levels of the heart and electrical activity by controlling hyperpolarization
Where in the heart are mACh receptors found?
The pacing centers: AV node and SA node
Which nerve predominantly effects the SA node?
right vagus nerve
Which nerve predominantly effects the Av node?
left vagus nerve
What type of receptor is the mACh receptor?
GPCR
What is the neurotransmitter found in the heart that relates to the heart rate?
Acetylcholine
What is one effect the G-protein and alpha unit from a mACh receptor have on the cell after acetylcholine binds?
They communicate with the potassium channels and open them.
What is result of the mACh stimulating K+ receptors?
Potassium leaves the cell making the cell more negative, which overall makes the cell harder to excite
How often does a normal action potential happen in a mACh receptor in the heart?
70-72bpm
What does having “massive vagal stimulation” do in the heart?
It increases permeability of K+ which lets K+ out of the cell and therefore makes the cells in the SA and VA more negative and slows the heart down.
What does everyone use to keep the brakes on the heart?
acetylcholine mediated hyperpolarization
What is the side effect of an anti muscarinic drug?
higher heart rate
What is basal acetylcholine?
Acetylcholine that is found naturally in our body
What happens when you give atropine to a healthy person?
It speeds up their heart rate by blocking the normal vagus activity in the heart, showing that we have basal ACh
What would our heart rate be if the nervous system wasn’t interferring?
110bpm
What are the two main types of muscarinic receptors in the heart?
muscarinic acetylcholine Receptor
Beta receptor
mACh-r and B-r _________ each other
Antagonize. Basically, the more ACh activity, it negates any catacolamine activity and vise versa
How does pressure stimulate an action potential?
There are a lot of pressure sensitive sodium channels inside the sensor.
When these are flattened out from pressure, the sodium channels are widened, allowing more Na+ to pass through them, making the cell more positive which generates an action potential.
What does the brain do in response to high pressure in our arteries?
adjusts our cardiac output and SVR
What is an example of a pressure sensor?
Baroreceptor
If we have enough pressure on our skin, what happens on the inside of our body?
If we have enough of a stimulus, the electrical activity at the sensor gets turned into an action potential, which then gets fed into a transmitting part of the neuron. This is then sent to the nervous system for processing in the form of action potentials.
If you have a lot of pressure on your skin you’re going to have ____
a lot of rapid action potentials
