Source: Video and Images Created by Amanda Soderlind
Welcome to this lesson today on digestive disorders and health.
Today we are going to be discussing various disorders of the digestive system.
The first disorder we're going to be discussing is a disorder that affects the upper digestive tract. This disorder is called gastroesophageal reflux, also commonly known as heartburn. This disorder basically occurs when chyme backs up in the esophagus, because the esophageal sphincter doesn't properly close. So if we look at a picture here, this would be our esophagus and this would be our stomach. And there's a sphincter that closes off the esophagus from the stomach. If this sphincter doesn't properly close, then chyme, which is a very acidic substance, will back up into the esophagus. That's what causes that heartburn sensation. It doesn't actually have anything to do with your heart, but you may feel it in the chest area as it backs up the esophagus. So that's commonly referred to as heartburn.
The next couple disorders we're going to talk about are disorders that affect the liver. Hepatitis is a disorder that affects the liver. Basically, hepatitis causes inflammation of the liver. This can be caused by viruses, which are transmitted by body fluids such as blood or semen. Or it can be caused by other factors, such as obesity, or drugs, or environmental toxins.
There's actually a couple different types of hepatitis that each have a little bit of a different cause. There's Type A. Hepatitis Type A, Hepatitis B and Hepatitis C, are the different types of hepatitis that can affect the liver, and cause inflammation of the liver. But fortunately, there are vaccines against these types of hepatitis. So it's generally not too much of a big deal, although people can still get hepatitis. But there is vaccines against it.
Cirrhosis is another disorder that affects the liver and it, again, causes the liver to become inflamed. This is due to heavy alcohol consumption over a person's life. So basically what happens is that this heavy alcohol consumption will damage liver cells, and then those damaged liver cells are replaced by connective tissue. So cirrhosis is inflammation of the liver related to heavy alcohol consumption.
Our next couple disorders are disorders that affect the colon. The colon is a part of the large intestine. It's the lower part of the large intestine. Crohn's disease is an inflammation disorder that affects the intestine, as well as other parts of the body, but today we're just going to focus on the intestine because it's a part of the digestive system. Crohn's disease is not curable, but it is treatable. So it's this inflammation disorder that can have an effect on the colon. Sometimes this will become so bad that a part of the intestine might have to be removed in order to help treat the disease.
Colorectal cancer is a cancer of the colon or rectum. This is actually responsible for about 20% of all cancer deaths yearly in the United States. So it's a fairly common type of cancer, but fortunately it can be detected by something called a colonoscopy, which is basically where a little camera is inserted into the colon in order to search for polyps. To search for polyps which are these growths that can be found on the colon wall, and are a warning sign of possible colorectal cancer.
These last couple disorders here are malabsorption disorders. These disorders occur when certain vitamins or nutrients are not properly absorbed by the digestive system.
Lactose intolerance is our first example. In lactose intolerance, the enzyme lactase is deficient. Lactase is an enzyme that allows for the absorption of lactose. Lactose is found in dairy products like cheese, milk, ice cream, et cetera. If a person doesn't have this lactase enzyme, if this enzyme is deficient, then they cannot properly absorbed lactose. So lactose intolerance is a disorder in which a person cannot properly digest or absorb lactose.
Cystic fibrosis is a genetic condition in which the pancreas doesn't provide enzymes for normal digestion and absorption of fats. A person who has cystic fibrosis-- and also this disorder, as I mentioned, it's genetic condition, and it also plays a role in the respiratory system, as well-- but one of the other effects that it has is that the person can't normally digests fats. So the pancreas isn't producing the enzymes necessary for digestion and absorption of fats.
the last two disorders are diarrhea and constipation. Both of these disorders basically have something to do with water not being properly absorbed. Either too much water is absorbed, or not enough water is absorbed, leading to one of these two conditions. So diarrhea, basically what happens with this condition is that an irritant-- some sort of irritant, or bacteria, or stress, or infection-- will cause the small intestine to secrete more water than the large intestine can absorb. That will result, then, in diarrhea because the feces is mixed with an excess amount of water. And this is actually something that can be scary for little kids because if too much water is excreted from the body and the body's not absorbing water like it should be, it can lead to dehydration.
Constipation is kind of the opposite of that. Constipation occurs when feces remains in the rectum for too long, and then too much water gets absorbed. And then the feces becomes very hard and compressed, and difficult to pass. Both of these, as I mentioned are either caused by not enough water being absorbed, or too much water being absorbed.
lesson has been an overview on various digestive disorders and health.