intestinal wall

(noun)

The wall of the small intestine is composed of four layers, from the outside to the inside: serosa, muscularis, submucosa, and mucosa.

Related Terms

Examples of intestinal wall in the following topics:

  • Histology of the Small Intestine

    • The small intestine wall has four layers: the outermost serosa, muscularis, submucosa, and innermost mucosa.
    • The intestinal villi are part of the mucosa.
    • The main function of these glands is to produce a mucus-rich, alkaline secretion (containing bicarbonate) in order to neutralize the acidic content of chyme that is introduced into the duodenum from the stomach, and to provide an alkaline condition for optimal intestinal enzyme activity, thus enabling absorption to take place and lubricate the intestinal walls.
    • Villi increase the internal surface area of the intestinal walls.
    • This increased surface area allows for more intestinal wall area to be available for absorption.

  • Absorption in the Small Intestine

    • Absorption of nutrients occurs partially by diffusion through the wall of the small intestine.
    • The small intestine is the part of the gastrointestinal tract between the stomach and the large intestine, and is where much of the digestion of food takes place.
    • Digested nutrients pass into the blood vessels in the wall of the intestine through a process of diffusion.
    • The inner wall, or mucosa, of the small intestine is lined with simple columnar epithelial tissue.
    • Structurally, the mucosa is covered in wrinkles or folds called plicae circulares, considered permanent features in the wall of the organ.

  • Amoebic Dysentery (Amoebiasis)

    • Dysentery is characterized as an inflammatory disorder of the intestine that results in severe diarrhea containing both mucus and blood in the feces, often accompanied with fever and abdominal pain.
    • Upon ingestion of contaminated foods or water, the cysts will move into the intestinal area.
    • Once in the intestine, the cyst breaks open and releases the amoebas which then burrow into and damage the intestinal walls.

  • Cholera

    • Cholera is an infection in the small intestine caused by the bacterium Vibrio cholerae.
    • Cholera is an infection in the small intestine caused by the bacterium Vibrio cholerae.
    • When the surviving bacteria exit the stomach and reach the small intestine, they need to propel themselves through the thick mucus that lines the small intestine to get to the intestinal walls, where they can thrive.
    • These flagella are cork-screw helical fibers that rotate to propel the bacteria through the mucus of the small intestine.
    • Once the cholera bacteria reach the intestinal wall, they no longer need the flagella to move.

  • Nematodes

    • The larvae burrow through the intestinal wall and begin circulation in the system and migrate to the lungs.
    • For a second time, the larvae enter into the intestine and mature into adult worms .
    • The presence of the worms within the intestine may also result in malabsorption or intestinal blockage.
    • Upon infection with eggs, they travel to the small intestine and hatch.
    • The pinworms exhibit the ability to mate in the small intestine.

  • Digestive System: Small and Large Intestines

    • Nutrients are absorbed in the small intestine and waste is prepared for elimination in the large intestine.
    • Digestive juices from the pancreas, liver, and gallbladder, as well as from gland cells of the intestinal wall itself, enter the duodenum.
    • The ileum is the last part of the small intestine.
    • The human large intestine is much smaller in length than the small intestine, but larger in diameter.
    • The rectum is the terminal end of the large intestine.

  • Histology of the Large Intestine

    • The large intestine has taeniae coli and invaginations (the intestinal glands), unlike the small intestines.
    • The large intestine differs in physical form from the small intestine in being much wider.
    • The wall of the large intestine is lined with simple columnar epithelium.
    • Instead of having the evaginations of the small intestine (villi), the large intestine has invaginations (the intestinal glands) .
    • In the intestine, the digestive enzymes are not secreted by the cells of the intestine.

  • Anatomy of the Large Intestine

    • The large intestine is about 4.9 feet (1.5 m) long—about one-fifth of the whole length of the intestinal canal.
    • The large intestine differs in physical form from the small intestine in several ways.
    • The wall of the large intestine is lined with simple columnar epithelium.
    • Instead of having the evaginations of the small intestine (villi), the large intestine has invaginations (the intestinal glands).
    • While both the small intestine and the large intestine have goblet cells, they are more abundant in the large intestine.

  • The Gallbladder

    • The gallbladder has a muscular wall that contracts in response to cholecystokinin, a peptide hormone that is synthesized by the small intestine.
    • When food containing fat enters the digestive tract, the secretion of cholecystokinin (CCK) is stimulated, and the gallbladder releases the bile into the small intestine.

  • Anatomy of the Small Intestine

    • The small intestine is the part of the gastrointestinal tract that follows the stomach, which is in turn followed by the large intestine.
    • The duodenum is the first section of the small intestine and is the shortest part of the small intestine.
    • The jejunum is the middle section of the small intestine.
    • The ileum is the final section of the small intestine.
    • The wall itself is made up of folds, each of which has many tiny finger-like projections known as villi on its surface.