The three major parts of stomach are

(a) Cardiac into which the oesophagus opens.

(b) Fundus which is commonly filled with air or gases.

(c) Pylorus which opens into small intestine (posterior part of stomach).

(a) Goblet cells are located in the intestinal mucosal epithelium and secrete mucus.

(b) Fats are broken down into di and monoglycerides with the help of lipases.

Fats $\xrightarrow{\text { Lipases }}$ Diglycerides $\longrightarrow$ Monoglycerides.

(c) Gastric glands of stomach mucosa have oxyntic cells which secrete HCl

(d) Saliva contains enzymes that digest starch.

$$\text { Starch } \frac{\text { Salivaryamylase }}{\mathrm{pH} 6.8} \text { Maltose }+ \text { Isomaltose }+\alpha \text {-dextrins }$$

The pancreas is a compound (both exocrine and endocrine) elongated organ situated between the limbs of ' $U$ ' shaped duodenum.

Internal structure of pancreas consist of two parts, i.e., the exocrine and endocrine part.

(i) Exocrine part consists of rounded lobules called acini that are involved in the secretion of alkaline pancreatic juice of pH 8.4. The pancreatic juice is mainly involved in the digestion of starch, proteins, fats and nucleic acids.

(ii) Endocrine part is involved in the secretion of hormones like, insulin and glucagon that regulate glucose metabolism.

Small intestine is the principle organ for the absorption of nutrients. The process of digestion complete here only and the final products of digestion are absorbed through the mucosa into the blood stream.

The absorbed form of different food materials are