Disorders of digestive system : There are following common disorders of digestive system in addition to infections of parasites.
1. Jaundice : In this the liver is affected and skin and eyes turn yellow due to the deposit of bile pigments (billirubin and biliverdin) in liver which pass into blood.
2. Vomiting : The ejection of stomach contents through the mouth. This reflex action is controlled by the vomit centre in the medulla. A feeling of nausea precedes vomiting.
3. Diarrhoea : The abnormal frequency of bowel movement and increased liquidity of the faecal discharge is known as diarrhoea.Tthe absorption of water is reduced. It occurs when less water is absorbed in colon from food.
4. Constipation : It occurs when excess of water is absorbed from faecal mater. In constipation the faeces are retained within the rectum as the bowel movements occur irregularly.
5. Indigestion : It is the process in which the food is not properly digested leading to feeling of fullness. The cause of indigestion are inadequate enzyme, secretion, anxiety, food poisoning, over eating and spicy food.
Diphyodont is the condition of having two set of teeth during the life of an organism. For example : humans are diphyodont as they have two set of teeth namely temporary milk or deciduous teeth which are replaced by permanent or adult teeth.