Digestive system
Digestive system is the system of organs that is responsible for food digestion.
This process includes breaking down large food particles into small molecules and
their absorption in the blood stream.
The digestive system consists of organs of digestive tract and accessory
organs.
The organs of digestive tract are the oral cavity, the pharynx, the
oesophagus, the stomach, the small and large intestines. The stomach is the Cshaped organ in the upper part of the abdomen. The small intestine starts with the
duodenum, then it is continued with the jejunum and it is finished with the ileum.
The large intestine consists of caecum, ascending colon, transverse colon,
descending colon, sigmoid colon and rectum.
The accessory organs of the oral cavity are teeth, tongue, gums, hard & soft
palates, salivary glands that secrete saliva. When the food enters the oral cavity, it is
crushed and chewed by teeth, moistened by saliva and mixed by the tongue. Bolus
is formed. It is pushed to the pharynx by the tongue. The accessory organs of the
stomach are gastric glands that secrete gastric juice. It is necessary for food
digestion. The accessory organs of the duodenum are the liver, the pancreas and the
gall bladder where bile is stored. The duodenum receives bile produced by the liver
and pancreatic juice produced by the pancreas. Undigested parts of food are mixed
with fluids to form faeces. They are stored in the rectum and later are excreted from
the body.