Introduction to Digestive System:

Digestive System

Digestive System

Digestive system is the food processing system of human body. The whole digestive system is in the form of a long, hollow, twisted and turned tube, called the alimentary canal, which starts from the oral cavity and ends at the anus. The overall process of digestion and absorption of food occurs in this tube. The tube is divided into different parts on the basis of structure and function of each part. These parts are described below.

Parts of the digestive system

Human digestive system consists of the two categories of parts. The first category consists of those organs that are directly involved in the process of digestion and absorption. The second category consists of those organs that aid the process of digestion and absorption of food by producing chemical substances or by some other way, but are not directly involved in the process of digestion and absorption. The first category of organs may be called as “necessary organs” and the second category as “accessory organs” but it should be kept in mind that without the aid of accessory organs, the process of digestion is seriously impaired. When the accessory organs fail to perform their functions completely, the process of digestion may also completely stop.
Necessary Organs Of the digestive system:

  1. ORAL CAVITY
  2. ESOPHAGUS
  3. STOMACH
  4. SMALL INTESTINE
  5. LARGE INTESTINE
  6. ANUS

Accessory Organs of the digestive system:

  1. LIVER AND GALLBLADDER
  2. PANCREAS
  3. SALIVARY GLANDS
  4. TEETH
  5. TONGUE

Functions of the digestive system:

As stated above, the digestive system is the food processing system of human body. The food taken by human beings is digested into simpler molecules that can be absorbed into the blood and utilized for various functions of human body. As the digestive system is the only route of intake of nutrients (in normal conditions), therefore necessarily all the nutrient requirements of human body are fulfilled by this system alone. If the digestive system is impaired for some reason, health of the affected individual will seriously decline.

Digestive System Outline:

Components
Necessary Organs
Oral cavity It is the cavity of mouth, irregular in shape, contains tongue, teeth and salivary glands,
Esophagus Muscular tube passing the food from pharynx to stomach
Stomach Muscular, hollow and dilated part of alimentary canal, involved in both mechanical and chemical digestion of food, secretes strong acid and enzymes to aid in digestion of food
Small Intestine Lies between stomach and large intestine, majority of digestion and absorption takes place here, About 5 meters in length
Large Intestine Second-to-last part of alimentary canal, main function is to absorb water from indigestible food.
Anus Last part of alimentary canal, opens to outside for ejection of food, Controls the expulsion of feces
Accessory Organs
Liver Produces bile for emulsification of fats
Pancreas Secretes pancreatic juice containing different digestive enzymes into the small intestine
Teeth Chewing and mastication of food
Tongue Rolling and lubrication of food
Functions Digestion and absorption of food