9. describe the function of the:
a. stomach
b. small intestine
c. large intestine

The stomach helps to store food temporarily. It also secretes gastric juices that digest food.

Most of the digestive process (digestion and absorption of food) takes place in the small intestine.

The funtions of large intestine are temporary storage of undigested and unabsorbed food, reabsorption of water and minerals, elimination of waste products (faeces) through the anus, helps in antibody production and acid reduction, maintaining a large population of bacteria living inside the intestine which produce gas, vitamin K etc.

Explanation:

The food that entered the stomach mixes with the gastric juices (hydrochloric acid and pepsin ) and get broken down into smaller components.

The partly digested food is then passed into the small intestine where the food is mixed with digestive juices from the pancreas, liver, and intestine and broke it down into smaller molecules (nutrients) which are absorbed into the blood in the small intestine. The inner wall of small intestine has finger-like projections called villi, which contains a network of capillaries and lymphatic vessels. Nutrients are transported to these capillaries and lymphatic vessels from the villi by diffusion. This nutrient rich blood is then pumped through the circulatory system to the other organs.

The undigested and unabsorbed food passes into the large intestine where water and some minerals are reabsorbed back into the blood. The remaining waste products are eliminated through the anus (defecation).  The large population of bacteria living inside the large intestine digest some material and creates gas, vitamin K etc. It has some role in antibody production and acid reduction also.

one centimetre is equal to 0.01 metres