Test Your Knowledge of Nutrition and Digestion in Humans

Nutrition and Digestive System in Human Beings

• Digestion of food starts in the mouth with the help of teeth, saliva, and the enzyme salivary amylase.
• The food is then swallowed by the tongue and goes down the food pipe called oesophagus.
• The stomach is a J-shaped organ that contains three tabular glands which secrete gastric juice containing hydrochloric acid, pepsin enzyme, and mucus.
• Hydrochloric acid kills bacteria and germs in food and creates an acidic medium that facilitates the action of enzymes.
• Pepsin enzyme converts protein present in food into peptones in the presence of hydrochloric acid.
• Mucus enzyme helps to protect the stomach wall from its own secretion of hydrochloric acid.
• Small intestine is the site of complete digestion of food and receives secretion from the liver and pancreas.
• Liver secretes bile juice that makes the acidic food coming from the stomach alkaline and breaks down fats into small globules.
• Pancreas secretes pancreatic juice which contains enzymes like pancreatic amylase, trypsin, and lipase for digestion of starch, proteins, and fats.
• The wall of the small intestine contains glands that secrete intestinal juice, which finally converts the proteins into amino acids, complex carbohydrates into glucose, and fats into fatty acids and glycerol.
• The small intestine is the main region for the absorption of digested food, and the inner wall has numerous finger-like projections called villi which increase the surface area for rapid absorption of digested food.
• The unabsorbed food is sent into the large intestine where villi absorb water from this material, and the rest of the material is removed from the body via the anus.