how do you appreciate the role of Alimentary canal nutrition of Human being
Answers
Explanation:
NUTRITION IN HUMAN BEINGS
Nutrition in human beings takes place through parts like mouth, stomach, small intestine, large intestine, anus
The process of nutrition takes place through an alimentary canal which is a long tube extending from the mouth to the anus.
Complex foods should be converted to smaller ones by crushing the food with teeth and by the enzyme salivary amylase of saliva secreted by salivary glands.
Salivary amylase breaks down starch which is a complex molecule into sugar.
As the canal lining is soft so food is made wet to make the passage smooth.
The alimentary canal has different parts and the food should be moved in a regulated manner along the digestive tube so the food is processed properly in each part.
The canal has muscles that contract rhythmically to push the food forward and this movement of food is called peristaltic movement which occurs all along the gut.
The food is taken to the stomach through the food pipe or oesophagus from mouth.
The muscular wall of stomach mixes the food with more digestive juices secreted by the gastric glands present in the wall of the stomach.
Gastric gland releases hydrochloric acid, a protein digesting enzyme called as pepsin, mucus.
Enzyme pepsin acts on the food and hydrochloric acid facilitates the action of pepsin.
Mucus protects the inner lining of the stomach from the action of acid under normal conditions.
From stomach acidic food enters small intestine, the longest part of alimentary canal and this is regulated by sphincter muscle.
Complete digestion of carbohydrates, protein and fats take place in the small intestine by the secretions of liver and pancreas.
Bile secreted by liver makes the acidic food alkaline and acts on large globules of fat into smaller globules so that the enzymes can act on easily.
The process of breakdown of large fats globules into small globules which increases the efficiency of the pancreatic enzymes is called
Pancreas secrete pancreatic juice which contains enzyme trypsin to break for digesting proteins, lipase for digesting emulsified fats.
The walls of the small intestine contain glands secreting intestinal juice which converts finally complex carbohydrates into glucose, proteins to amino acids and fats into fatty acids and glycerol.
The inner wall of small intestine has finger like projections called villi which are richly supplied with blood vessels and these take absorbed food to all the cells of the body.
The unabsorbed food is sent to the large intestine where more villi absorb water from this undigested material and the rest of the material is excreted from the body by anus.
The excretion of waste materials by anus is regulated by the anal sphincters.