Question

Describe in detail digestion that takes place in the small intestine?

Answer 1

Hint: Small intestine is the part of the digestive tract, which is present between the stomach and large intestine, and it is the part of the digestive tract where the end absorption of the nutrients and minerals takes place, and it is the place where most of the chemical absorption occurs, and it receives pancreatic juice as well as bile juice, and small intestine itself divided into three parts.

Complete answer:
A) The length of the small intestine is ranging from 3 to 5m, where and it may present more also, where it depends on the height of the individual.
B) The diameter of the small intestine is 1.5cm in newborns and adults it is one inch, if it is dilated more than 2.5 then it is considered abnormal.
C) The small intestine is divided into three parts which include the Duodenum, Jejunum, Ileum.
D) Duodenum: it is the smallest part of the small intestine which range from 20 to 25cm, and it is C shaped structure, and it is a finger like projections which is helpful for the absorption which called villi, and the duodenum receives chyme from the stomach and it also receives pancreatic juice and bile juice, and Brunner’s gland is present where it secreted a mucous rich substance that is alkaline. And it is the place where most of the chemical absorption takes place.
E) Jejunum: It is the part of the small intestine after the duodenum, where the Suspensory portion of the duodenum marks it is the mid-portion and it is mostly 2 meters long and this part contains the plicae circulares and villi, where these portions increase the surface area and in this place absorption of a digested portion of carbohydrates, fats and amino acids take place.
F) Ileum: It is the final portion where 3meters long, and as villi similar to that of Jejunum and it is the portion where the vitamin B12 absorption and absorption of bile acids and as well as nutrients takes place.

Note: Small intestine also plays a role in immune, as the presence of gut flora in the small intestine and presence of Peyer’s patch are examples of its immune function, and gut flora is friendly microbes which help synthesize the important nutrients in the body.