Source:Wikipedia
Digestion involves the breakdown of food into smaller and smaller particles,until they can be absorbed and assimilated into the body. DIgestion begins from the first stage "Cephalic phase" of which digestion starts with gastric secretions due to response to the smell and sight of food substance. it also includes the breakdown of food substance by chewing and the enzymes or catalyst does a chemical breakdown in the mouth.
This is also known as the gastrointestinal (GI) tract. This is essentially a long tube through which food passes. It starts from the mouth and ends at the anus.
Source:istock
And to this, there are various organs along its length with different function although structurally they are similar. The parts includes :
Various waste products extractions in the body are poured into the alimentary tract as transported by the glands in the lining membrane of the organs. for instance gastric juice secreted by glands in the lining of the stomach and some by glands situated outside the tract. The latter are the accessory organs of digestion
Source:wikipedia
And the secretions pass through ducts to enter the tract. They consist of :
-three pairs of salivary glands
-the pancreas
-the liver and biliary tract.
The organs and glands are linked physiologically as well as anatomically in the digestion and absorption occur in stages. Each stage being dependent on the previous stage or stages. The layers of the walls of the alimentary canal follow a set pattern from the oesophagus onwards. From the oesophagus onwards, modification of structure occurs.
Source:wikipedia The walls of the alimentary tract are formed by four layers of tissues they are:
This is the outermost layer. In the thorax,it consists of loose fibrous tissue and in the abdomen,the organs are covered by a serious membrane (sensa) called peritoneum. The peritoneum and associated structures.
This consists of two layers of involuntary muscle. The fibres muscles of the outer layer are arranged longitudinally and the inner layer encircle the wall of the tube. Between the muscles are blood vessels,lymph vessels and plexus of parasympathetic and sympathetic nerves called myentenic plexus.
It consists of loose areolar connective tissue containing collage and some elastic fibres that binds the muscle layer to the mucosa.
It consists of 3 layers of tissues
