Welcome back to the weekly blog from Upstate Sports and Spine! In this second part of my ongoing series about the levels of the nervous system, I am going to discuss the remainder of the brainstem. We began this discussion talking about the mesencephalon, and now we will head about an inch south and look at the pons and the medulla oblongata.
Wait, you’re saying to yourself – why did we devote an entire entry to one part of the brainstem, yet cover two parts in the next one? Are the other two parts less important?
Not at all! We look at the pons and medulla together because there is a good deal of overlap in their function, especially at their junction. But first, let’s break them down individually:
The pons fills many roles that are important to our functioning. It is primarily composed of conducting fibers and acts as a relay center between the higher levels of the brain, the spinal cord, and the cerebellum. The pons also houses the nerves and neural tissues that are responsible for horizontal eye movements, working in concert with the mesencephalon. Within the pons, you will also find the two centers that control how deep we inhale and exhale, known as the apneustic and pneumotaxic centers. On top of all that, extensive research has highlighted the importance of the pons in generating deeper levels of sleep, including REM sleep.
Pretty important stuff! And we’re just getting started…
When we move down to the medulla oblongata, we find the nerve centers that control heart rate and blood pressure. These nerve centers can actually instruct the body to raise and lower heart rate and blood pressure to help serve the body’s needs. So between the breathing centers in the pons, and the cardiac centers in the medulla, you can see that even the most basic elements of human functioning cannot effectively function without a healthy brainstem.
But there’s more! So much more!
The medulla gives rise to a very important nerve – the Vagus nerve. No doubt, you’ve heard myself or Dr. Uribe talk about the importance of the Vagus, which literally means “wandering” in Latin. It descends from the brainstem, through the skull, and then it heads down, down, down. And along the way, it makes stops in the larynx, the electrical centers of the heart that control rate and rhythm, the lungs, stomach, and the first half of the large intestine.
Let’s finish off all the heavy science with one more very important function of the pons and medulla. At the pons/medulla junction, we find the root of the vestibular nerve and the vestibular nerve centers. These nerves control your inner ear balance and equilibrium centers, but they also go downward to the deep muscles in the back and rib cage, and upward to the nerve centers that control eye movement.
Here is the take-home message: balance in the eyes, the inner ears, and the muscles that control posture are deeply linked to one another! And the links occur in the brainstem!
This is just a very basic overview of all the different functions of the brainstem. I could easily talk about this for hours on end, and I haven’t even gone into detail on the 12 nerves that emerge from the brainstem, the cranial nerves, that control most of the functions of our head and neck! Maybe some other time…
At the end of the day, I hope I have shown you how important it is to ensure the health of the brainstem, all three sections of it. Thanks for slugging through some heavy-duty science with me. Next week, we’ll take a break from all the terminology and talk about some of the therapies I use in treating patients and how they help ensure a healthier, more balanced nervous system. As always, I welcome your feedback via email at firstname.lastname@example.org, or on Twitter at DrMParekhNeuro. And please visit our website to learn more about how we can help you!