GENERAL KNOWLEDGE

     DIGESTION

The Body Needs the Nutrients in Food to Grow .Maintain Its Structure, And Provide Energy, But the Food until It Is Processed by the Digestive System. This Essentially A Long Tube, Running From  Mouth To Annus.As Food Passes A Long  The Digestive System It Is Chewed, And Crushed, And Then Broken Down Chemically By Enzymes, As It Passes Along The Small Intestine, Food Resembles A Thin Soup, And Simple Food Molecules Can Be Absorbed Into The Body Itself By Way Of The Bloodstream.

          Swallowing 

Once Food Is Chewed, The Tongue Pushes The Ball Of Food, Or Bolus, To The Back Of The Mouth. As It Touches The Throat, The Bolus Triggers A Reflex Action And Passes Into The Oesophagus. A Flap Called The Epiglottis Closes The Entrance To The Trachea To Stop Food Entering The Lungs.

      Peristalsis

Rhythmic Contraction of the Muscles in the Wall of the Oesophagus Squeeze Food Down To The Stomach. This Wave Like Movement Is Called Peristalsis, It Also Occurs In The Small Intestine.

       Digestive Process 

        

        The digestive process has four stages

1)    Ingestion

Ingestion is the process by which food is taken into the alimentary canal.  It includes the processes that take place while the food is in the mouth, such as chewing and grinding using the teeth, the lubrication and chemical effects of saliva released from the salivary glands, and swallowing of the food - which sends it onwards down the digestive tract.

2)   Digestion

Digestion is the process by which ingested (food) material is broken down in the earlier stages of the alimentary canal into a form that can then be absorbed and assimilated into the tissues of the body.Digestion includes two types of processes -

• Mechanical (e.g. chewing, grinding, churning, mixing), and

• Chemical (e.g. action of digestive enzymes, bile, acids, etc.).

The mechanical processes include the chewing and grinding of food by the teeth and also the churning and mixing of the contents of the stomach.Chemical processes that contribute to digestion also begin in the mouth with action of saliva on food. However, most of the chemical digestive processes occur in the stomach and small intestine - where the partly-digested materials are subjected to gastric juices, pancreatic juice, success entericus and so on

3)   Absorption

  Absorption is the uptake of fluids or other substances by the tissues of the body.
Digested "food"  is absorbed into the bodily fluids blood and lymph from the alimentary canal. Most of the absorption part of the digestive process occurs in the jejunum and the ileum of the small, though alcohol is readily absorbed through the stomach. The small intestine is lined with minute finger-like processes (called "villi", a single example being a "villus"), that greatly increase its surface area, and hence the rate at which absorption can take place.Assimilation is the process by which components/chemicals from food (incl. liquid refreshments such as milk drinks, fruit juices etc.) are taken into the cells of the body - after the food/beverage has been digested and absorbed.

  4) Egestion

Elimination is the final stage of this 4-stage summary of digestion. In physiology more generally the term "elimination" can apply to the entire process of excretion of metabolic waste products, incl. from the blood via the kidneys and urinary tract.

    Food and Enzymes

   Enzymes Are Biological Catalyst That Speed Up The Conversion Of One Substance Into Another. Digestive Enzymes Are Speed Up the Breakdown of the Complex Carbohydrates, Fats, and Proteins That Make Up Most of Our Food.

       William Beaumont 

William Beaumont was a surgeon in the U.S. Army who became known as the "Father of Gastric Physiology" following his research on human digestion.