Question

Trace the various steps of digestion of food from the time it is placed in the mouth to the time it gets absorbed by cells.​

Answer 1

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    Buccal cavity:

• The food first enters our body through our mouth/buccal cavity and the salivary glands present in the cavity release the saliva along with salivary amylase which acts upon the carbohydrates in the food and breaks it down into simple sugars.

    Oesophagus :

• Then the food enter our oesophagus and moves down towards the stomach via the peristaltic movement . It is approx. 25cm long with sphincters present at both ends to prevent the food from going into the wind pipe at the top and also to prevent food going back from stomach at the bottom.

    Stomach:

• It has the gastric gland present in its walls which release the Hydrochloric Acid which plays an important role in killing the bacteria in the food and also provide an acidic medium for the enzyme pepsin to get activated and act on the proteins to break them down and it also release mucus which makes an outer covering for the inner stomach lining to protect it from the strongly acidic Hydrochloric Acid as the lining of stomach is thin.

    Liver and Pancreas:

• The liver secretes the bile juice which provides the basic medium for the pancreatic enzymes which are the pancreatic lipase which brakes down the fat globules into the tiny fat particles . Pancreatic amylase completes digestion of carbohydrate, producing glucose, a small molecule that is absorbed into your blood and carried throughout your body .

    Small intestine:

• The digested food enters the small intestine and the small intestine walls have ville present which increases the surface area and absorbs the digested food particles and the rest is passed into the large intestine.

    Large intestine:

• The leftover food enters the large intestine the water and the salt are reabsorbed back and the left if thrown out of the body as the feceal  matters through anus.