State the role of the following in human digestive system :
(i) Digestive enzymes
(ii) Hydrochloric acid
(iii) Villi
(iv) Liver
(v) Large Intestine
Answers
Explanation:
(i) Digestive enzymes – Foods need to be broken into their small or simpler molecules so that they can be absorbed into the bloodstream. However, the physical breakdown of food is not enough. Enzymes are hence needed for the chemical breakdown of food and speeding up the digestive process. The products of digestion can hence be small enough to be absorbed. (ii) Hydrochloric acid – Hydro chloric acid helps to kill the germs which might have entered in to the system through food. It creates acidic medium for the pepsin to act on food to breakdown proteins. (iii) Villi – Villi are finger like projections in the small intestine. They help to increase the surface area for absorption of the digested food. Villi are richly supplied with blood vessel which help to absorb digested food in to the blood stream.
The purpose of the large intestine is to absorb water and salts from the material that has not been digested as food, and get rid of any waste products left over. By the time food mixed with digestive juices reaches your large intestine, most digestion and absorption has already taken place.
Liver. The liver has many functions, but its main job within the digestive system is to process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat and some vitamins.