The small intestine comes between the gastrointestinal tract and the large intestine. It has a small diameter and is 6 meters long. Its surface area is approximately the same as that of a tennis court. The small intestine is slightly basic because pancreatic juice contains sodium bicarbonate(NaHCO3).
The surface area of the small intestine contains finger-like projections called villi. They have a soft and velvety appearance. Each villus has thousands of microscopic extensions called micro-villi. They give villi a fuzzy border known as a "brush border". This border increases the surface area and helps in the absorption of nutrients. The nutrients are absorbed into the vessels of a villus.
A villus contains blood capillaries and a small lymphatic capillary called a lacteal. Sugars and amino acids enter the blood capillaries. Glycerol and fatty acids enter the epithelial cells. In the cells they are joined and packaged as lipoprotien droplets and then enter the lacteal. After this absorption process finishes, the nutrients are transported to the organs of the body through the blood stream.
By: Katie, Monica, Anne, and Anna
No comments:
Post a Comment