As peristalsis continues, the waste products of the digestive process move into the large intestine. Large intestine. Waste products from the digestive process include undigested parts of food, fluid, and older cells from the lining of your GI tract. The large intestine absorbs water and changes the waste from liquid into stool.
Peristalsis helps move the stool into your rectum. The lower end of your large intestine, the rectum, stores stool until it pushes stool out of your anus during a bowel movement. Watch this video to see how food moves through your GI tract. As food moves through your GI tract, your digestive organs break the food into smaller parts using:.
The digestive process starts in your mouth when you chew. Your salivary glands make saliva , a digestive juice, which moistens food so it moves more easily through your esophagus into your stomach. Saliva also has an enzyme that begins to break down starches in your food. After you swallow, peristalsis pushes the food down your esophagus into your stomach. Glands in your stomach lining make stomach acid and enzymes that break down food.
Muscles of your stomach mix the food with these digestive juices. Your pancreas makes a digestive juice that has enzymes that break down carbohydrates, fats, and proteins. The pancreas delivers the digestive juice to the small intestine through small tubes called ducts.
Your liver makes a digestive juice called bile that helps digest fats and some vitamins. Bile ducts carry bile from your liver to your gallbladder for storage, or to the small intestine for use.
Your gallbladder stores bile between meals. When you eat, your gallbladder squeezes bile through the bile ducts into your small intestine. Your small intestine makes digestive juice, which mixes with bile and pancreatic juice to complete the breakdown of proteins, carbohydrates, and fats.
Bacteria in your small intestine make some of the enzymes you need to digest carbohydrates. Your small intestine moves water from your bloodstream into your GI tract to help break down food. Your small intestine also absorbs water with other nutrients.
In your large intestine, more water moves from your GI tract into your bloodstream. Bacteria in your large intestine help break down remaining nutrients and make vitamin K. Waste products of digestion, including parts of food that are still too large, become stool. The small intestine absorbs most of the nutrients in your food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross the intestinal lining into your bloodstream.
Your blood carries simple sugars, amino acids, glycerol, and some vitamins and salts to the liver. Your liver stores, processes, and delivers nutrients to the rest of your body when needed. The lymph system , a network of vessels that carry white blood cells and a fluid called lymph throughout your body to fight infection, absorbs fatty acids and vitamins.
Your body uses sugars, amino acids, fatty acids, and glycerol to build substances you need for energy, growth, and cell repair. Only small, soluble substances can pass across the wall of the small intestine. Large insoluble substances cannot pass through. The slideshow shows how this happens:. Food molecules in the small intestine are too large to pass across its wall and into the bloodstream. Carbohydrase enzymes in the small intestine begin to digest the food into smaller molecules.
The food molecules are now small enough to move by diffusion through the wall of the small intestine into the bloodstream. Absorption across a surface happens quickly and efficiently if:. The inner wall of the small intestine has adaptation so that substances pass across it quickly and efficiently:. What remains consists of the indigestible components of food such as cellulose from the consumption of plant-based foods. These materials are then passed on to the large intestine. It has been estimated that there are over species of bacteria present in the large intestine, and these friendly commensal bacteria perform a variety of functions.
For example, undigested carbohydrates fibre are metabolised to short-chain fatty acids, and small amounts of vitamins, especially vitamin K and the vitamin B group, are produced for absorption into the blood. As undigested material accumulates in the rectum, it stimulates a response that leads to the evacuation of the waste through the anus.
Add to collection. Go to full glossary Add 0 items to collection. Download 0 items. Twitter Pinterest Facebook Instagram. Email Us. See our newsletters here. Would you like to take a short survey?
0コメント