Question

Which of the following are secreted by duodenum or small intestine?
A)Enterokinin
B)Secretin
C)Villikinin
D)All of the above

Answer 1

Small intestine is an important part of the digestive system. The duodenum is the upper most part of the small intestine. The small intestine works together with the enzymes of the liver and pancreas and helps in breaking down food. It absorbs all the important nutrients from the food into the bloodstream.

Complete answer:
The small intestine consists of three distinct regions-Duodenum, jejunum and ileum.
The duodenum is the shortest region where the food prepares for absorption. It consists of a finger like villi where the absorption takes place. Jejunum is lined by enterocytes which absorbs small nutrient particles from the previously digested food. Ileum absorbs vitamin B12, bile salts and other important unabsorbed nutrients from the food.

The small intestine duodenum produces enzymes and hormones like-
1)Enterokinin- It is secreted by the Brunner’s gland. It plays a major role in activating the inactive pancreatic enzyme and converting procarboxypeptidase into carboxypeptidase.
2)Secretin- It is directly secreted into the bloodstream by the duodenum. It activates the secretion of pancreas and liver.
3)Villikinin- It is secreted by the mucosa and increases the motility of the villi.

Hence, the correct answer is option (D)

Note: The duodenum receives the food along with gastric juices from the stomach and the enzymes and hormones from the pancreas and liver. These enzymes break down proteins and fats. The secretion is rich in bicarbonate. The bicarbonate helps in neutralising the acidic nature of the gastric enzymes.