Search results
Results From The WOW.Com Content Network
The circular folds slow the passage of the partly digested food along the intestines, and afford an increased surface for absorption. [5] They are covered with small finger-like projections called villi (singular, villus). Each villus, in turn, is covered with microvilli. The microvilli absorb fats and nutrients from the chyme.
In the small intestine, villi are folds of the mucosa that increase the surface area of the intestine. The villi contain a lacteal , a vessel connected to the lymph system that aids in the removal of lipids and tissue fluids.
The small intestine is the site where most of the nutrients from ingested food are absorbed. The inner wall, or mucosa, of the small intestine, is lined with intestinal epithelium, a simple columnar epithelium. Structurally, the mucosa is covered in wrinkles or flaps called circular folds, which are considered permanent features in the mucosa.
The combination of the circular folds, the villi, and the microvilli increases the absorptive area of the mucosa about 600-fold, making a total area of about 250 m 2 (2,700 sq ft) for the entire small intestine. [20] Its main function is to absorb the products of digestion (including carbohydrates, proteins, lipids, and vitamins) into the ...
These folds together with villi serve to increase the surface area of the jejunum enabling an increased absorption of digested sugars, amino acids and fatty acids into the bloodstream. The circular folds also slow the passage of food giving more time for nutrients to be absorbed. The last part of the small intestine is the ileum.
The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds.Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been previously digested by enzymes in the duodenum.
Intestinal villi (sg.: villus) are small, finger-like projections that extend into the lumen of the small intestine. Each villus is approximately 0.5–1.6 mm in length (in humans), and has many microvilli projecting from the enterocytes of its epithelium which collectively form the striated or brush border. Each of these microvilli are about 1 ...
There is a wider distance between haustra than between the circular folds of the small intestine, and the haustra do not reach around the entire circumference of the intestine, in contrast to circular folds of the small intestine that do. These differences can assist in distinguishing the small intestine from the colon on an abdominal x-ray.