midgut

The midgut is a segment of the gastrointestinal tract located between the duodenum (the first part of the small intestine) and the ileum (the final portion of the small intestine). It primarily consists of the jejunum and ileum, which are responsible for most of the digestive and absorptive functions in the small intestine. The midgut arises from the embryonic gut during development, originating from the midsection of the primitive gut tube.

The jejunum, the middle section of the small intestine, is characterized by its thick walls and extensive vascular supply, which facilitate nutrient absorption. It contains villi and microvilli, microscopic projections that increase surface area for absorption of nutrients such as carbohydrates, proteins, and fats. The ileum, which follows the jejunum, is narrower and has fewer villi, primarily absorbing vitamin B12, bile salts, and remaining nutrients.

The midgut also plays a role in the development of the lower abdominal organs, including parts of the intestines, liver, and gallbladder, as well as the urinary system and the middle portion of the large intestine. Congenital abnormalities of the midgut, such as malrotation or volvulus, can occur if the gut fails to rotate properly during development, potentially leading to life-threatening complications.

Blood supply to the midgut is primarily provided by the superior mesenteric artery, which branches off from the abdominal aorta. This artery ensures adequate perfusion to the midgut structures, supporting their metabolic and functional activities. The midgut’s anatomical position and functions make it a critical component of the digestive system, essential for the efficient processing and absorption of food.