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An illustration and description of the digestive system

Convert food into nutrients your body needs Rid the body of waste Main Contents of the Digestive System The human body has specifically evolved to suit the available nutrients in the environments in which humans evolved. And there are several specialized organs nature has designed to make the most of ingested food. The human abdominal cavity stretches from the diaphragm to the pelvis at the pelvic brim and contains the hollow and tube-like alimentary tract, or digestive organs, of the body.

  1. Bacteria in the large intestine can also break down food. As peristalsis continues, the waste products of the digestive process move into the large intestine.
  2. Saliva also has an enzyme that begins to break down starches in your food.
  3. Food starts to move through your GI tract when you eat. Arrangement of Liver in the Abdomen Medical Illustration.

These vital organs include the mouth, esophagus and stomach. The stomach continues into the small intestine, which consists of the duodenum, jejunum, ileum, and cecum. Digestion continues with the large intestine: There are many accessory organs, solid in structure, which aid in digestion and these include the liver, gall bladder, kidneys, pancreas, and spleen. Arrangement of Liver in the Abdomen Medical Illustration.

  • The pancreas delivers the digestive juice to the small intestine through small tubes called ducts;
  • Smooth muscle in the stomach contracts during digestion, in order to break down nutrients;
  • Enzymes, including proteases, amylases, and lipases released throughout the digestive system, break down the swallowed food;
  • Your small intestine makes digestive juice, which mixes with bile and pancreatic juice to complete the breakdown of proteins, carbohydrates, and fats;
  • The largest parts of the digestive system include;
  • Your body uses sugars, amino acids, fatty acids, and glycerol to build substances you need for energy, growth, and cell repair.

Enzymes, including proteases, amylases, and lipases released throughout the digestive system, break down the swallowed food. Even the mouth releases amylase and lipase in the saliva. Amylases break down carbohydrates, lipases break down fats, and proteases break down proteins.

Layers of the Stomach Lining This gastric illustration depicts the three layers of smooth muscle which line the stomach wall. Smooth muscle in the stomach contracts during digestion, in order to break down nutrients.

The muscle layers in the human stomach are each striated in different directions. Because smooth muscle can only contract in one direction, it is functionally adaptive for the stomach, which must contract as an organ overall, to contract in three directions.

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Another muscle in the body which has muscle fibers running in different directions is the tongue. The stomach is the only organ in the digestive system to have three muscle layers. The rest of the gastrointestinal tract, or GI tract, contains only two muscle layers. Diaphragm, abdomen, stomach, ileum, duodenum medical illustration. Illustrated by medical illustrator Laura Maaske. And because of the microvilli which make a very convoluted surface, the actual surface area of the small intestine is 2,700 square ft 250 square m.

Large Intestine The large intestine gets its name because it is wider than the small intestine. Rectum The rectum is the last section of the digestive system. It holds and forms the feces before it is released. Accessory Organs to the Digestive Tract Gall bladder — assists in lipid digestion and concentrates bile produced by the liver. Kidneys — regulate enzymes, maintain acid and salt balance, and regulate of blood pressure and water balance.

The kidneys remove waste and divert toxins to the ureter and urinary bladder. The kidneys produce urine, which contains urea and ammonium. The kidneys also manufacture the hormones erythropoietin and calcitriol; and the enzyme renin. Pancreas — a digestive organ as well as an endocrine gland.

  • There are many accessory organs, solid in structure, which aid in digestion and these include the liver, gall bladder, kidneys, pancreas, and spleen;
  • When food stretches the walls of your GI tract, the nerves of your ENS release many different substances that speed up or delay the movement of food and the production of digestive juices.

As a digestive organ it releases pancreatic enzymes for the small intestine to break down proteins, lipids, and carbohydrates.

As a gland it produces vital hormones like insulin, glucagon, pancreatic polypeptide, and somatostatin. Spleen — as part of the lymphatic and immune system, and less vital than the other organs, the spleen filters blood.

It removes the old red blood cells from blood and holds a reserve of blood if there should be sudden hemorrhage somewhere in the body. The spleen recycles iron, removes bacteria which have been identified as foreign by immune cells, and synthesizes antibodies.

Other Contents of the Abdomen Generally, the bladder and ureters, uterus and ovaries, are considered part of the pelvis and not the abdomen, due to the perimeter of the abdominal wall itself, the peritoneum. However, there is some disagreement about this.

  • Diaphragm, abdomen, stomach, ileum, duodenum medical illustration;
  • Nerves You have nerves that connect your central nervous system—your brain and spinal cord—to your digestive system and control some digestive functions;
  • Bacteria in your large intestine help break down remaining nutrients and make vitamin K;
  • The connection between all of these organs and their fluids requires a delicate balance that can easily be disrupted by numerous factors, including diet, stress, disease, and more.

These organs are considered to be in a retroperitoneal position. A retroperitoneal position is to be located in the back of the peritoneal or pelvic cavity as opposed to within the abdominal cavity. The left gastric artery supplies the lesser curve of the stomach. And the lft and right gastroepiploic arteries supply the greater curve of the stomach. The splenic artery supplies the spleen with blood. The left and right hepatic arteries supply the liver.

The right and left renal arteries supply the kidneys.