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Information about Jejunum

Small intestine
Superior and inferior duodenal fossæ.
subject #248 1170
Arteryintestinal arteries
Nerveceliac ganglia, vagus [1]
Precursormidgut
MeSH Jejunum
In anatomy of the digestive system, the jejunum is the central of the three divisions of the small intestine and lies between the duodenum and the ileum. The change from the duodenum to the jejunum is usually defined as the ligament of Treitz.

In adult humans, the small intestine is usually between 5.5-6m long, 2.5m of which is the jejunum.

The pH in the jejunum is usually between 7 and 8 (neutral or slightly alkaline).

The jejunum and the ileum are suspended by mesentery which gives the bowel great mobility within the abdomen. It also contains muscles to help move the food along.

Internal structure

The inner surface of the jejunum, its mucous membrane, is covered in projections called villi, which increase the surface area of tissue available to absorb nutrients from the gut contents. The villi in the jejunum are much longer than in the duodenum or ileum.

The jejunum contains very few Brunner's glands (found in the duodenum) or Peyer's patches (found in the ileum). Instead, it has many large circular folds in its submucosa called plicae circulares which increase the surface area for nutrient absorption.

Etymology

Jejunum is derived from the adjective jejune, which means "fasting" or "hungry" in Early Modern English. It was so called because this portion of the intestine was found "empty" following death [Latin: jejunus, fasting; barren]

Additional images


Duodenojejunal fossa.

Transmission electron microscope (TEM) of Human Jejunum

TEM of Mouse Jejunum x14000


References

External links

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Anatomy of torso, digestive system: Gastrointestinal tract
Upper GI: to stomachMouth • Pharynx (nasopharynx, oropharynx, hypopharynx) • Esophagus • Crop
Upper GI: stomachrugae - gastric pits - cardia/gland - fundus/gland - pylorus/gland - pyloric antrum - greater curvature - lesser curvature
Lower GI: intestinesSmall intestine (duodenum, jejunum, ileum) • Vermiform appendix • Ileocecal valve - Large intestine: Cecum • Colon (ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon)
Lower GI: after intestinesRectum (Houston valve, rectal ampulla, pectinate line) • Anal canal (anal valves, anal sinuses, anal columns) - Anus: Sphincter ani internus muscle • Sphincter ani externus muscle
Lower GI: continuousGALT: Peyer's patches • M cells - intestinal villus • crypts of Lieberkhn • circular folds • taenia coli • haustra • epiploic appendix
Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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The intestinal arteries arise from the convex side of the superior mesenteric artery. They are usually from twelve to fifteen in number, and are distributed to the jejunum and ileum.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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The Celiac Ganglia (semilunar ganglia) are two large irregularly shaped masses having the appearance of lymph glands and placed one on either side of the middle line in front of the crura of the diaphragm close to the suprarenal glands, that on the right side being placed behind
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The vagus nerve (also called pneumogastric nerve or cranial nerve X) is the tenth of twelve paired cranial nerves, and is the only nerve that starts in the brainstem (within the medulla oblongata) and extends, through the jugular foramen, down below the head, to the
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Embryology is the study of the development of an embryo. An embryo is defined as any vertebrate in a stage before birth or hatching. Embryology refers to the development of the egg cell (zygote) after fertilization and the differentiation of cells into tissues and organs.
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The midgut is the portion of the embryo from which most of the intestines are derived. After it bends around the superior mesenteric artery, it is called the "midgut loop".
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Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed
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Anatomy (from the Greek ἀνατομία anatomia, from ἀνατέμνειν
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The digestive system is the organ system that breaks down and absorbs nutrients that are essential for growth and maintenance. The digestive system includes the mouth, esophagus, stomach, pancreas, liver, gallbladder, duodenum, jejunum, ileum, (intestines), rectum, and anus.
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In biology the small intestine is the part of the gastrointestinal tract (gut) between the stomach and the large intestine and includes the duodenum, jejunum, and ileum. It is where the vast majority of digestion takes place.
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In anatomy of the digestive system, the duodenum is a hollow jointed tube about 25-30 cm long connecting the stomach to the jejunum. It is the first and shortest part of the small intestine and it is where most chemical digestion takes place.
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ileum is the final section of the small intestine. It is about 2-4 m long in humans, follows the duodenum and jejunum, and is separated from the cecum by the ileocecal valve (ICV). The pH in the ileum is usually between 7 and 8 (neutral or slightly alkaline).
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The suspensory muscle of the duodenum is the proper name of what is commonly known as the ligament of Treitz (named for Václav Treitz), and it refers to tissue that connects the duodenum of the small intestines to the diaphragm.
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    pH is a measure of the acidity or alkalinity of a solution. Aqueous solutions at 25 ℃ with a pH less than seven are considered acidic, while those with a pH greater than seven are considered basic (alkaline). The pH of 7.
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    alkali (from Arabic: Al-Qalyالقلي, القالي ) is a basic, ionic salt of an alkali metal or alkaline earth metal element.
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    Mesentery is, in anatomy, the double layer of peritoneum that connects a part of the small intestine to the posterior wall of the abdomen. Its meaning, however, is frequently extended to include double layers of peritoneum connecting various components of the abdominal cavity.
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    The mucous membranes (or mucosae; singular: mucosa) are linings of mostly endodermal origin, covered in epithelium, and are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs.
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    Villus (Latin: "shaggy hair"[1], plural villi) can refer to:
    • Intestinal villus. This is the most common meaning when not more precisely specified
    • Chorionic villi, found on the surface of the outermost membrane (the chorion) of the fetus

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    Brunner's glands (or duodenal glands) are compound tubular submucosal glands located throughout the duodenum. The main function of these glands is to produce an alkaline secretion (containing bicarbonate) in order to:

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    Peyer's patches are secondary lymphoid organs, named after the 17th-century Swiss anatomist Johann Conrad Peyer. They are aggregations of lymphoid tissue that are usually found in the lowest portion of the small intestine (ileum) in humans; as such, they differentiate the ileum
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    The circular folds (valves of Kerckring) are large valvular flaps projecting into the lumen of the bowel.

    They are composed of reduplications of the mucous membrane, the two layers of the fold being bound together by submucous tissue; unlike the folds in the stomach,
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    In the gastrointestinal tract, the submucosa is the layer of loose connective tissue that supports the mucosa, as well as joins the mucosa to the bulk of underlying smooth muscle (fibers running circularly within layer of longitudinal muscle).
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    Fasting is primarily the act of willingly abstaining from some or all food, drink, or both, for a period of time. Concerning that from which one fasts, and the period of fasting, a fast may be total or partial.
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    Early Modern English}}}
    Language codes
    ISO 639-1: en
    ISO 639-2: —
    ISO 639-3: — Early Modern English refers to the stage of the English language used from about the end of the Middle English period (the latter half of the 15th
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