Why do we get a falling feeling in our stomachs when we drop on a roller coaster? The falling feeling we get in our stomachs on a roller coaster happens because some of the organs in our abdomen, especially the stomach and intestines, are more free to shift than organs that are more firmly supported. The feeling does not come only from the stomach, though. Several bodily systems are working together here, but the stomach is the part we notice most.
We have many internal organs, including the brain, lungs, heart, stomach, intestines, liver, kidneys, spleen, and bladder. When we look at a biology teaching aid, it can seem as though they are all just floating around inside an empty body, but that is not what the body is really like. Most of our organs are held in place by layers of connective tissue, membranes, and ligaments. There is dense connective tissue called fascia, which helps support and separate structures, and there are also membranes inside the abdomen that help anchor the organs and keep them in their proper positions. The abdomen is not hollow space, either. Whatever room is not occupied by organs is filled with muscle, fat, fluid, blood vessels, connective tissue, and other structures. The organs can move a little, because they need to, but most of them do not move very far.
The stomach and intestines are a bit different. They are still attached and supported, of course, but they have to be more flexible than many of the other organs. The stomach needs room to stretch when it fills with food, and the intestines need to keep moving food along. The muscles in the walls of the digestive system contract in waves, a motion called peristalsis, to push food through the body. Because of that, these organs are not held as rigidly as something like the liver or kidneys. They have more freedom to shift when the body suddenly changes speed or direction.
That matters when we drop. If a body suddenly accelerates downward, the more firmly supported organs and tissues move with the body more immediately, while the more mobile organs lag behind slightly because of inertia. Inertia is the tendency of an object to resist a change in motion. A simple way to picture it is to imagine holding one ball tightly in one hand and another ball hanging loosely from a string in the other. If a person suddenly jumps down, the ball being held tightly moves immediately with the hand, while the hanging ball lags for a moment before the string pulls it along. Something similar happens inside the abdomen. During a sudden drop, the stomach and intestines shift slightly relative to the rest of the body, and that produces the strange light, hollow, or rising sensation that is described as the stomach falling.
Part of the feeling also comes from temporary weightlessness. On a roller coaster drop, the seat is no longer pushing upward on the body as strongly as it was a moment before. For a brief instant, the body and the organs inside it are all falling together. That changes the pressure sensations inside the abdomen and chest. The stomach can feel oddly light, as though it has lifted upward, even though what has really changed is the force acting on it. It is not that the stomach literally flies up inside the body, but that it shifts and feels lighter because the usual downward pressure has suddenly decreased.
The nerves in the body notice these changes very quickly. The brain is constantly receiving information about movement, pressure, balance, and the position of the body. A sudden drop is unusual enough that the brain treats it as something important. That can trigger the release of adrenaline and other stress responses, which add to the strange sensation. The heart may beat faster, breathing may change, and the whole body becomes more alert. That alert response makes the feeling in the stomach more noticeable and more dramatic.
The vestibular system in the inner ear is also involved. This is the part of the body that helps detect balance, acceleration, and movement. On a roller coaster, the inner ear is suddenly telling the brain that the body is dropping, accelerating, and changing direction very quickly. At the same time, the eyes are reporting fast movement and the abdomen is reporting shifting pressure and organ movement. The brain has to combine all of that information at once. That is why the sensation is not just in the stomach. It can come with dizziness, excitement, fear, or that odd floating feeling that is hard to describe.
The digestive system itself is also full of nerves. The gastrointestinal tract contains a vast network of neurons known as the enteric nervous system. This system helps control digestion independently of the brain and spinal cord, which is why it is sometimes called the second brain. It is not a second brain in the literal sense, but it is extremely sensitive and active. That is another reason strange sensations in the abdomen can feel so immediate and powerful. When all of these things are combined, shifting organs, changing pressure, balance signals, and the body’s stress response, the result is that unmistakable falling feeling in the stomach. And this is what I learned today.
Sources
https://science.howstuffworks.com/engineering/structural/roller-coaster6.htm
https://my.clevelandclinic.org/health/body/22894-peritoneum
Photo by Tim Gouw: https://www.pexels.com/photo/cyclone-roller-coaster-ride-160098/