Biology chapter 2

 Food into the small Intestine

*From stomach food reaches the small intestine in small quantities. 

* The partially digested food reaches the beginning part of the small intestine called duodenum.

Duodenum

*The beginning of the small intestine a 'U' shaped structure called the duodenum.

*It is a ‘U’ shaped structure that carries the food from the stomach to the small intestine. 

* It helps to mix the secretion of liver (bile) and pancreas (pancreatic juice). 

* On the right side of the stomach is the largest gland, liver. It is the only organ that is capable of regeneration.

Digestive juices that reach the duodenum

*Bile secreted by liver

* Pancreatic juice secreted by pancreas.

*Both these secretions flow to the duodenum through a common duct

The role of liver in the process of digestion:

* Liver is the largest gland in the body which is seen above the duodenum, on the right side of the stomach, just below the diaphragm. 

* Liver secretes bile and it is temporarily stored in the gall bladder.

* Bile juice secreted by the liver converts larger fat globules into smaller particles, and makes the food alkaline in nature; it thus helps in the digestion of fat.(There is no enzyme in bile)

Liver -Bile - No enzymes present 

*It does not take part in the process of 

digestion directly.

*Bile converts the acidic food from the 

stomach to basic.(Alkaline)

* It emulsifies fat into smaller globules.

Role of pancreas in the process of digestion:

* It secretes pancreatic juice.

* Pancreatic juice it consists of three enzymes Pancreatic lipase, trypsin and Pancreatic amylase.

* Pancreatic amylase converts starch into maltose.

* Trypsin converts proteins into peptides.

* Pancreatic lipase converts fat and oils into fatty acid and glycerol.

Pancreas -Pancreatic juice 

Pancreatic amylase converts Starch → Maltose 

Trypsin converts Protein → Peptides

Pancreatic lipase converts Fats →Fatty acid + Glycerol

(Digestion of fat is completed)

* completion of digestion and absorption of nutrients take place in the small intestine.

* The inner wall of the small intestine consists of tiny glands called intestinal glands which secrete intestinal juices. It consists of two type enzymes.  Enzyme associated with the digestion of protein  and enzyme associated with the digestion of carbohydrate.