Question

Describe the alimentary canal of man.

Answer 1

Human Alimentary canal has the following parts :-

1. Buccal Cavity : Generally called a mouth and it consists of tongue, teeth and salivary gland. It is the entry site for the food to the digestive system. Food is broken down into simpler molecules by mastication in the buccal cavity and salivary amylase breaks Starch into simpler carbohydrates in the Buccal cavity.
2. Oesophagus : Buccal cavity is connected to the long tube-like structure called Oesophagus. Oesophagus connects the buccal cavity to the stomach and assists the inflow of food towards the stomach. Oesophagus has a valve to prevent backflow of food particles.

3. Stomach : - Stomach is a J Shaped organ which has gastric glands in it. Gastric glands secrets Hydrochloric acid, Pepsin and Mucus that helps in the digestion of food.

4. Small Intestine : - The small intestine is a lengthy, tightly coiled structure. The small intestine is responsible for a large portion of food absorption. Specialized features in the small intestine aid in the absorption of digested food. The folds in the small intestine improve the absorption area. The small intestine also features microvilli, which are fingerlike projections that are well-supplied by blood vessels. 

5. Large Intestine : - This is shorter than the small intestine and its lumen is larger than that of the Small intestine. The major function of the large intestine is to absorb water from the remaining indigestible food matter and transmit the useless waste material from the body. 

6. Rectum : - Large Intestine opens into rectum. Waste materials and undigested food are stored in the rectum.

7. Anus : - It is the opening at the end of the alimentary canal. Solid waste materials leave the body through Anus.