Find out what the vagus nerve (cranial nerve X) does in your body. While perhaps not as impressive, you’ll also find out what the accessory nerve (cranial nerve XI) does and why it is important to the vagus nerve.
A Nerve that Seems to Do Everything
Every ship has a captain. That doesn’t mean that every other crew member is insignificant.
Not at all; in some respects, they may be more significant than the captain, depending on the location they’re stationed on the ship or what it is they do. In the same way, your body has this one big nerve – the captain, so to speak – which seems to play a role in everything your body does. Just like a captain cannot steer the ship entirely on his own, he needs some auxiliary or accessory team members, who will help him do his job well. Therefore, we’ll also look at another nerve in this lesson, as all the nerves in your body, no matter how big or small, have important roles to play in the ship.
The Vagus Nerve or Cranial Nerve X
In the game of soccer, the #10 shirt is usually given to the playmaker, most important player or captain of the team.
Our body has a nerve called cranial nerve X, also known as the vagus nerve, which is a very important player in our body. This is because it’s a nerve that innervates the heart, lungs and the digestive tract. There is one vagal nerve on either side of your body.Given the fact that this nerve is involved in controlling the heart, lungs and digestive tract (along with functions like swallowing, sweating and speaking), you should be able to clearly tell how important it is to our body. Like the captain of a ship or the playmaker of a soccer game, it seems to play a role in everything.
The Vagus Nerve and the Heart
If you were to think of your heart as the engine of the ship, then the captain (our vagus nerve) plays a role in controlling the speed of the ship (meaning our heart rate). The vagus nerve exits our head, travels down the neck, into the thorax and, finally, all the way down into the abdomen. It’s a really long and big nerve.As the nerve passes near the heart, it extends out little tentacles – like the fingers of the ship captain’s hand – which grab onto the heart. These tentacles, which are really just other nerves, help to put a stop to a high heart rate. Essentially, if the captain (the vagus nerve) wants to slow down the ship, he will lower the heart rate and hence the engine driving our body.
The Vagus Nerve and Digestion
The captain of a ship is also responsible for ensuring the proper loading of the ship with fuel. In our case, our body’s fuel comes from our food. The captain must ensure that our body – our ship – gets enough of this fuel for movement.Therefore, the vagus nerve is involved in controlling muscles that help us swallow our food and move it along our digestive tract in a process we call ‘peristalsis.’ Peristalsis is basically a series of muscular contractions and expansions in your gastrointestinal tract that serve to move food down the GI tract.
The Accessory Nerve or Cranial Nerve XI
As you can clearly tell, the vagus nerve is truly like a captain of a ship; it does a lot of important things. However, the ship’s captain needs to be able to move his head around if he is to see what is going on in his ship, so that he can bark out commands if something needs to be changed.One of the muscles involved in moving your head around is innervated by the accessory nerve, also called cranial nerve XI.
Remember, as with every single other cranial nerve in your body, they are paired. There is one of each on each side of your body.
In addition to helping the captain’s head move around, this nerve innervates muscles that give you the ability to shrug when you are doing shrugs while lifting weights or realize you don’t really care about something and decide to shrug it off. All in all, the accessory nerve is a nerve that helps to move our head around and gives us the ability to shrug.
Hopefully, you aren’t going to shrug off the main parts of this lesson.
Therefore, let’s review them one more time.Cranial nerve X, also known as the vagus nerve, is a nerve that innervates the heart, lungs and the digestive tract. It’s like the captain of our ship, serving to help your heart rate decrease, help you swallow your food and help the food move down the entire gastrointestinal tract.While not as impressive, the accessory nerve, also called cranial nerve XI, has some functionality as well. It is a nerve that helps to move our head around and gives us the ability to shrug.
While that doesn’t seem all that impressive, if the captain can’t move his head around very well in order to see what’s wrong with his ship, he can’t do anything to prevent it from hitting an iceberg. And, I think that’s pretty important!
You’ll be able to explain the importance and functionality of the vagus nerve and the accessory nerve after viewing this lesson.