The digestive system comprises of gastrointestine tract with various gland attached to it. The tract start from mouth and ends at the anus, the tract is around 8-10m in length. The activity in the digestive system can be grouped under 5 main headings they are;
- Ingestine; It is the process of taking the food into the alimentary tract i.e drinking and eating.
- propulsion; this mixer and moves the contents along the alimentary tract.
- Digestion; It is the mechanical breakdown of food by mastication and the chemical digestion of food into small molecules by enzymes presention secretion produced by gland and accessory organs of the digestive system.
- Absorption; this is the process by which digestive food substance passes through the walls of somes organs of the alimentary canal into the blood and lymph capillaries for circulation and use by blood cells.
- Elimination; Food substance that have been eater but can not be digested and absorbed are excreted from the alimentary canal as faeces by the process of defaecation.
Organs of the digestive ststem:
It includes Alimentary tract and Accessory organs.
Alimentary tract: It is also known as gastrointestinal tract and is a long tube through which the food passes, it starts from the mouth and ends at the anus, the various parts are:
- Mouth/oral cavity
- Pharynx
- Oesophagus
- Small intestine
- Large intestine
- Rectum and Anus canal
The accessory organs include:
- 3 pairs of salivary glands
- pancreas
- liver and biliary tract.