*Digestive tract or Digestive system.

 The digestive tract is functionally divided into two main groups or  parts, Alimentary canal so called *Gastrointestinal tract [GIT]

 &  Accessory digestive organs, as example for a large Digestive glands, like, Salivary glands, liver, & pancreas….etc….NB: In a way the liver  includes the accessory D/glands is by production of bile secretion, although it has many metabolic & regulatory processes…. such as; filtration of blood composition….

So, The GIT is a continuous muscular digestive tube, that breaks down food into small fragments [i.e. dissolve] * and also absorbs into the blood.

 The digestive system  involves six  essential  activities:

1-  Ingestion (i.e. intake of food).

2- Mechanical digestion (i.e. breaking down of food into small particles by chemically, [ by enzymes]  & by physically [act of chewing]         [*occur in oral cavity.]

3- Propulsion (i.e. act of swallowing, It is about the movement of muscular layer…

4- Chemical digestion (i.e. act of dissolving and mixing with enzymes, * this complex steps Occur in stomach and complete in duodenum [stomach/duodenum]

5- Absorption (i.e. transported into the blood stream at absorptive site).

& Finally 6- Defecation (i.e. Eliminates indigestible substances via the anus).