The liver is the body’s second-largest organ, second only to the skin. This approximately 3-pound, football-sized organ plays an important role making sure our bodies are functioning properly. Some of the liver’s most important roles in digestion include cleansing the blood, storing energy, and helping with digestion. Show
The Digestive SystemThe digestive system is made up of several organs:
The Liver’s Role In DigestionWhile the liver (along with the pancreas and gallbladder) isn’t officially part of the digestive system, it plays an important role as food is digested and makes its way from top to bottom (literally). “Anything that is eaten or consumed, whether it’s food, alcohol, medicine or toxins, gets filtered by the liver,” says Hellan Kwon, M.D. clinical assistant and professor of hepatology at the University of Michigan. “Once we ingest food, it is digested by the stomach and intestine, gets absorbed into the blood, and goes to the liver.” Within the digestive system, the liver’s main role is to process materials absorbed by the small intestine and create the necessary chemicals. Essentially, the liver is the body’s chemical factory. It processes nutrients so that they can be used by the rest of the body. It also creates albumin, a blood protein which transports hormones, drugs, and fatty acids through the body. In addition to its role as a chemical factory, the liver is also a sort-of fat factory. When fats are consumed, the liver breaks them down. It also creates bile, which converts excess carbohydrates and proteins and stores them for later use. Bile is absolutely necessary for digestion. It helps the body absorb fat into the bloodstream and helps to carry unusable waste products and toxins out of the body through the stool. Regulation, Detoxification and EliminationThe liver also breaks down toxic substances like drugs, alcohol, and medicines. It removes them by excreting waste into the blood which is then cleansed by the kidneys. Waste that is filtered by the kidneys will then be removed from the body through the urine. Another role of the liver is to ensure a healthy level of blood sugar by removing sugar from the blood and storing it as glycogen. When blood sugar levels are low, the liver will convert the glycogen to glucose, adding an energy boost to the bloodstream. When blood sugar levels are high, the liver can remove glucose from the blood as needed to keep the sugar levels constant. Keeping your organs healthy is a lifestyle choice that affects your overall health. Check out our blog titled Seven Ways to Keep your Organs Healthy for more information. The food you eat takes an incredible journey through your body, from top (your mouth) to bottom (your anus). Along the way the beneficial parts of your food are absorbed, giving you energy and nutrients. Here’s a step-by-step account of the digestive system’s workings.
OverviewStructure of the Digestive SystemWhat is the digestive system?Your digestive system is made up of the gastrointestinal (GI) tract and your liver, pancreas and gallbladder. The GI tract is a series of hollow organs that are connected to each other from your mouth to your anus. The organs that make up your GI tract, in the order that they are connected, include your mouth, esophagus, stomach, small intestine, large intestine and anus. What does the digestive system do?Your digestive system is uniquely constructed to do its job of turning your food into the nutrients and energy you need to survive. And when it’s done with that, it handily packages your solid waste, or stool, for disposal when you have a bowel movement. Why is digestion important?Digestion is important because your body needs nutrients from the food you eat and the liquids you drink in order to stay healthy and function properly. Nutrients include carbohydrates, proteins, fats, vitamins, minerals and water. Your digestive system breaks down and absorbs nutrients from the food and liquids you consume to use for important things like energy, growth and repairing cells. AnatomyWhat organs make up the digestive system?The main organs that make up the digestive system (in order of their function) are the mouth, esophagus, stomach, small intestine, large intestine, rectum and anus. Helping them along the way are the pancreas, gall bladder and liver. Here’s how these organs work together in your digestive system. MouthThe mouth is the beginning of the digestive tract. In fact, digestion starts before you even take a bite. Your salivary glands get active as you see and smell that pasta dish or warm bread. After you start eating, you chew your food into pieces that are more easily digested. Your saliva mixes with the food to begin to break it down into a form your body can absorb and use. When you swallow, your tongue passes the food into your throat and into your esophagus. EsophagusLocated in your throat near your trachea (windpipe), the esophagus receives food from your mouth when you swallow. The epiglottis is a small flap that folds over your windpipe as you swallow to prevent you from choking (when food goes into your windpipe). A series of muscular contractions within the esophagus called peristalsis delivers food to your stomach. But first a ring-like muscle at the bottom of your esophagus called the lower esophageal sphincter has to relax to let the food in. The sphincter then contracts and prevents the contents of the stomach from flowing back into the esophagus. (When it doesn’t and these contents flow back into the esophagus, you may experience acid reflux or heartburn.) StomachThe stomach is a hollow organ, or "container," that holds food while it is being mixed with stomach enzymes. These enzymes continue the process of breaking down food into a usable form. Cells in the lining of your stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process. When the contents of the stomach are processed enough, they’re released into the small intestine. Small intestineMade up of three segments — the duodenum, jejunum, and ileum — the small intestine is a 22-foot long muscular tube that breaks down food using enzymes released by the pancreas and bile from the liver. Peristalsis also works in this organ, moving food through and mixing it with digestive juices from the pancreas and liver. The duodenum is the first segment of the small intestine. It’s largely responsible for the continuous breaking-down process. The jejunum and ileum lower in the intestine are mainly responsible for the absorption of nutrients into the bloodstream. Contents of the small intestine start out semi-solid and end in a liquid form after passing through the organ. Water, bile, enzymes and mucus contribute to the change in consistency. Once the nutrients have been absorbed and the leftover-food residue liquid has passed through the small intestine, it then moves on to the large intestine (colon). PancreasThe pancreas secretes digestive enzymes into the duodenum that break down protein, fats and carbohydrates. The pancreas also makes insulin, passing it directly into the bloodstream. Insulin is the chief hormone in your body for metabolizing sugar. LiverThe liver has many functions, but its main job within the digestive system is to process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat and some vitamins. The liver is your body's chemical "factory." It takes the raw materials absorbed by the intestine and makes all the various chemicals your body needs to function. The liver also detoxifies potentially harmful chemicals. It breaks down and secretes many drugs that can be toxic to your body. GallbladderThe gallbladder stores and concentrates bile from the liver, and then releases it into the duodenum in the small intestine to help absorb and digest fats. ColonThe colon is responsible for processing waste so that emptying your bowels is easy and convenient. It’s a 6-foot long muscular tube that connects the small intestine to the rectum. The colon is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left) colon, and the sigmoid colon, which connects to the rectum. Stool, or waste left over from the digestive process, is passed through the colon by means of peristalsis, first in a liquid state and ultimately in a solid form. As stool passes through the colon, water is removed. Stool is stored in the sigmoid (S-shaped) colon until a "mass movement" empties it into the rectum once or twice a day. It normally takes about 36 hours for stool to get through the colon. The stool itself is mostly food debris and bacteria. These “good” bacteria perform several useful functions, such as synthesizing various vitamins, processing waste products and food particles and protecting against harmful bacteria. When the descending colon becomes full of stool, or feces, it empties its contents into the rectum to begin the process of elimination (a bowel movement). RectumThe rectum is a straight, 8-inch chamber that connects the colon to the anus. The rectum's job is to receive stool from the colon, let you know that there is stool to be evacuated (pooped out) and to hold the stool until evacuation happens. When anything (gas or stool) comes into the rectum, sensors send a message to the brain. The brain then decides if the rectal contents can be released or not. If they can, the sphincters relax and the rectum contracts, disposing its contents. If the contents cannot be disposed, the sphincter contracts and the rectum accommodates so that the sensation temporarily goes away. AnusThe anus is the last part of the digestive tract. It is a 2-inch long canal consisting of the pelvic floor muscles and the two anal sphincters (internal and external). The lining of the upper anus is able to detect rectal contents. It lets you know whether the contents are liquid, gas or solid. The anus is surrounded by sphincter muscles that are important in allowing control of stool. The pelvic floor muscle creates an angle between the rectum and the anus that stops stool from coming out when it’s not supposed to. The internal sphincter is always tight, except when stool enters the rectum. This keeps us continent (prevents us from pooping involuntarily) when we are asleep or otherwise unaware of the presence of stool. When we get an urge to go to the bathroom, we rely on our external sphincter to hold the stool until reaching a toilet, where it then relaxes to release the contents. Conditions and DisordersWhat are some common conditions that affect the digestive system?There are temporary conditions and long-term, or chronic, diseases and disorders that affect the digestive system. It’s common to have conditions such as constipation, diarrhea or heartburn from time to time. If you are experiencing digestive issues like these frequently, be sure to contact your healthcare professional. It could be a sign of a more serious disorder that needs medical attention and treatment. Short-term or temporary conditions that affect the digestive system include:
Common digestive system diseases (gastrointestinal diseases) and disorders include:
CareHow can I keep my digestive system healthy?If you have a medical condition, always ask your healthcare provider what you should do and eat to stay healthy and manage your condition. In general, the following are ways to keep your digestive system healthy:
When should I contact my healthcare provider about digestive system issues?Contact your healthcare provider if you are experiencing frequent symptoms such as constipation, diarrhea, vomiting, stomach pain or cramps, excessive gas (farting), or heartburn. While most people experience these conditions every once in a while, if you experience them often, it could be a sign of a more serious digestive system issue. Share Facebook Twitter LinkedIn Email Print Last reviewed by a Cleveland Clinic medical professional on 08/09/2021. References
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What are 5 functions of the liver?The primary functions of the liver are:. Bile production and excretion.. Excretion of bilirubin, cholesterol, hormones, and drugs.. Metabolism of fats, proteins, and carbohydrates.. Enzyme activation.. Storage of glycogen, vitamins, and minerals.. Synthesis of plasma proteins, such as albumin, and clotting factors.. |