Question

Why is the small intestine the most important organ of the digestive system?

Answer 1

Small intestine is the most important gastric organ of our body. It is the main organ of the digestive system where all the digestion takes place. It lies in between the stomach and the large intestine. Most of the absorption of food and nutrients takes place in the small intestine.

Complete answer:
To solve this question, we must know the structure and function of the small intestine.
The small intestine is a 6.5m long organ where digestion and absorption of the food takes place. It extends from the stomach to the large intestine. It receives bile and pancreatic juice from the pancreatic duct which helps in complete digestion of food.

The parts of the small intestine are:
1.Duodenum- it is the first part of the small intestine which contains finger-like projections called villi. These villi help in absorption of food. It contains Brunner's gland which secretes duodenum and helps in digestion of fats.

2.Jejunum- It has the lining of enterocytes which absorb small particles which has been digested by the duodenum. The nutrients digested are sugar, amino acid, fatty acids.

3.Ileum- Ilium is the last part of the small intestine. Its function is to absorb vitamin B, bile and the other undigested particles received from the jejunum.

The secretion from the pancreas is transported to the duodenum which aids in digestion of the food and further nutrients are absorbed.

Note: The small intestine supports the microbes present in our body which aid in digestion of food and also secrete essential nutrients needed by our body. The peyer's patch present in the small intestine prevents the growth of microorganisms in the small intestine.