The other day, a student asked me a great question about how to prepare for TEAS nervous system questions.
Because she asked such a great question, I thought I’d share with you.
“What’s the opposite of acetylcholine?”
Oooh…. do you know the answer?
Because 3 different people could have 3 different answers… and everyone could be right. 🤯
By the way, let’s real quick talk about why this is a great question because it shows a really great TEAS study strategy in action.
She’s gone beyond the general definitions of a neurotransmitter. She’s found a specific neurotransmitter that is emphasized by the TEAS.
Now, she’s thinking about how it functions in the body, comparing it to other processes, and examining its relationships to other chemicals in the body.
This is higher-level thinking.
Now, if you are thinking, “Cooooool, but, ummmm, what the heck is acetylcholine?”
Don’t worry. You are not alone!
Stick with me here. You’ll have a better understanding of everything after you finish this post.
So let’s dive in!
Keep Reading: Anatomy and Physiology Study Tips
By the way, what’s the answer to her question?
The short answer?
It depends. 🤨
Isn’t the TEAS fun? 😅
The answer could be three things… an anticholinergic agent OR norepinephrine OR cholinesterases.
We’ll talk about why soon…AND which one the TEAS is most likely to focus on, so keep reading.
You’ll need to be familiar with the basics of neurotransmitters for the TEAS. Plus, you’ll need to know how specific neurotransmitters work in the body.
Now, I don’t want you to get lost in the details here.
You’ll learn more details when you get to nursing school, but don’t worry about those now.
We’re going to focus on what you need to know for the TEAS.
Neurotransmitter = chemical messenger released by nerves
These chemical messages are often short, quick messages. For example, nerve cells release neurotransmitters to tell muscles to move.
If you want your fingers to type, your brain will tell your nerves to tell your finger muscles to move.
But only when you want them too! Your fingers aren’t typing all the time (I hope).
So far, we’ve covered that neurotransmitters are…
- Chemical messengers
- Released by neurons
- Send quick, short-acting signals
- Act on other tissues, particularly muscles.
For TEAS Nervous System questions, it’s super important to know that neurotransmitters act on muscles in specific ways.
TEAS Nervous System Study Tip #1: The neuromuscular junction is the gap between a neuron and a skeletal muscle.
Skeletal muscles are responsible for voluntary movement (think: moving your fingers to type).
Voluntary means it is controlled by your conscious thought.
At the neuromuscular junction, acetylcholine rules.
In order to send the message to move these muscles, nerves release the neurotransmitter acetylcholine.
Acetylcholine is like the ON switch for voluntary skeletal muscles. This chemical messenger travels from the neuron to the muscle, activating it.
Right now, we’ve talked about acetylcholine’s role in voluntary muscle movement.
Acetylcholine, however, is also important for involuntary movement. Let’s talk about that now.
TEAS Nervous System Study Tip #2: Different neurotransmitters have different roles in the autonomic nervous system.
The autonomic nervous system is a broad classification for body responses that happen automatically.
In other words, these are body movements that happen under involuntary control.
These are responses like smooth muscle movement (peristalsis and contraction/dilation of arteries) and the beating of the heart.
Keywords for autonomic muscle movement are peristalsis and dilation.
Where in this chart are the neurotransmitters released?
The autonomic nervous system has two divisions:
- Parasympathetic nervous system
- Sympathetic nervous system
Here’s a quick recap of each for you:
😴 Parasympathetic nervous system study points for the TEAS:
✔ “Rest and digest” or “feed and breed”
✔ Slows breathing rate and heart rate
✔ Dilation of blood vessels for relaxation
✔ Encourages digestion (peristalsis)
✔ Main neurotransmitter = acetylcholine
😬 Sympathetic nervous system study points for the TEAS:
✔ “Fight or flight”
✔ Increases breathing rate and increases heart rate
✔ Increases contraction of blood vessels to increase blood pressure + keep blood in core of body
✔ Slows digestion — reduces blood flow to the digestive organs
✔ Main neurotransmitter = norepinephrine
Notice that each response relies on a different neurotransmitter. This is important for the TEAS!
For the TEAS, you’ll need to be familiar with 2 important neurotransmitters involved in the autonomic nervous system.
TEAS Neurotransmitter #1: Acetylcholine
💪 Somatic/Non-autonomic nervous system = released at the neuromuscular junction to stimulate skeletal muscles under voluntary control
😴 Autonomic nervous system = promotes parasympathetic system’s “rest and digest” 😌 throughout the body for muscles and tissues under involuntary control
This brings us to a possible opposite of acetylcholine.
Sometimes, too much acetylcholine can cause problems in the body.
For example, what’s another word for way too much peristalsis in the intestines? Uh, diarrhea.
Acetylcholine can make the body “runny,” including diarrhea and excessive mucus production.
Remember the movie Cool Runnings about a dedicated and hard-working Jamaican bobsled team?
Acetylcholine is your body’s cool runnings.
It keeps you calm, cool, and collected… OR runny.
Runny in a way you don’t want to be.
Medications called anticholinergic agents can block this excessive acetylcholine.
In this case, the opposite of acetylcholine could be an anticholinergic agent.
Anticholinergic agents sit in certain binding sites so that acetylcholine can’t bind and activate them. By doing this, the agents slow down the overactive runny response.
Benadryl is an example of an anticholinergic agent.
TEAS Neurotransmitter #2: Norepinephrine
😬 Autonomic nervous system = promotes sympathetic nervous system’s “fight or flight” response throughout the body for muscles and tissues under involuntary control 📌 Memorize for the TEAS
💓 Also good to know: Used by the body to control blood vessel constriction… even when the body is not under huge stress
🧠 Also good to know: stimulates the adrenal glands to release epinephrine to enhance fight or flight signalling
In this case, norepinephrine could be the opposite of acetylcholine.
The “flight or fight” response is opposite response of the “rest and digest” response, and each uses an opposite neurotransmitter.
In fact, this is what the TEAS is most likely to emphasize.
Be sure you review the important points we just reviewed about these two neurotransmitters!
OK, if the most important point about neurotransmitters on the TEAS is how they are used in the parasympathetic vs. sympathetic nervous system… and sometimes medications act against acetylcholine… what’s the THIRD possible opposite of acetylcholine?
Cholinesterases. Cholinesterases function as enzymes. They are also released at the neuromuscular junction to break down acetylcholine.
If acetylcholine breaks down, it can’t stimulate skeletal muscle movement.
By breaking down acetylcholine, cholinesterases help keep the message of acetylcholine short-acting, which is an important trait of many neurotransmitters.
Therefore, cholinesterases help return muscles back to their resting state.
This, however, is getting into more complicated physiology than you’ll need to know for the TEAS. You’ll learn more about this later as you continue your education.
OK, we’ve covered so much in this post. To wrap up, let’s go through some quick questions that can summarize these concepts for you!
Quick Answers to Your TEAS Nervous System & Neurotransmitter Questions:
🤔 This was a lot of information! Can you summarize the most important points?
Point #1: Context is important on the TEAS.
Try to get clear on the question first before you answer it. In this example, the “opposite” of acetylcholine has at least 3 possible answers.
Point #2: Acetylcholine is a very important neurotransmitter in the neuromuscular system.
📌 Memorize for the TEAS: It’s released at the neuromuscular junction to activate skeletal muscles AND it is the primary neurotransmitter of the parasympathetic nervous system (“cool runnings”).
It’s possible opposites are…
Norepinephrine = the primary neurotransmitter of the sympathetic nervous system 📌 Memorize for the TEAS
Anticholinergic agents = physically blocks acetylcholine from binding at certain sites, thus canceling acetylcholine’s activation
Cholinesterases = break down acetylcholine at the neuromuscular junction as part of a normal body response
🤔 What’s the difference between norepinephrine and epinephrine?
Norepinephrine is a neurotransmitter released by nerves, and epinephrine is more frequently released by the adrenal glands.
Norepinephrine helps control blood pressure AND activates the sympathetic nervous system during times of stress.
During times of stress, the adrenal glands can also release norepinephrine. Norepinephrine promotes the release of epinephrine.
Nerves do not always release epinephrine; the adrenal glands release epinephrine during times of stress.
🤔 Do I need to know any other neurotransmitters for the TEAS?
Yes. For example, histamine is considered to be a neurotransmitter involved in immunity. You can learn more about histamine in the immunity module of the online program.
🤔 Is norepinephrine the same thing as an anticholinergic agent?
Norepinephrine promotes the OPPOSITE body responses of acetylcholine.
Anticholinergic agents physically block acetylcholine from binding in the body.
🤔 If I learned something more complex in my college A&P class, will it be on the TEAS?
Probably not—but it will likely show up in nursing school when you get there. 🙂
For example, the functioning of cholinesterases is something you’ll need to know as you continue your education, but it’s unlikely to be a scored question on the TEAS.
🤔 What if I need more help with this?
Check out my full online program! You’ll get study guide workbooks, more practice questions, and illustrations to help this information stick.
You’ll find an entire unit dedicated to the neuromuscular system.
If you are looking for a quick refresher, my Quizlet study sets can also help you, too. Happy studying!