Jejunum
The jejunum (/dʒᵻˈdʒuːnəm/) is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds.
The jejunum lies between the duodenum and the ileum. The jejunum is considered to begin at the attachment of the suspensory muscle of the duodenum to the duodenum, a location called the duodenojejunal flexure. The division between the jejunum and ileum is not anatomically distinct. In adult humans, the small intestine is usually 6-7m long, about two fifths of which (2.5 m) is the jejunum.
Structure
The interior surface of the jejunum—which is exposed to ingested food—is covered in finger like projections of mucosa, called villi, which increase the surface area of tissue available to absorb nutrients from ingested foodstuffs. The epithelial cells which line these villi have microvilli. The transport of nutrients across epithelial cells through the jejunum and ileum includes the passive transport of sugar fructose and the active transport of amino acids, small peptides, vitamins, and most glucose. The villi in the jejunum are much longer than in the duodenum or ileum.
Podcasts:
Jejunum
ALBUMS
- Kiirastuli, Volume 2 released:
