- Human digestive system is composed of alimentary canal and digestive glands.
- Mouth is made up of teeth, tongue and salivary glands.
- Teeth masticates the food, tongue mixes food with saliva and salivary gland secrete an enzyme salivary amylase which breaks down starch into simple forms.
- After mouth food enters into the pharynx, and then passes through a tube like structure called the esophagus with the help of peristaltic movement.
- Food reaches the stomach.
- Stomach is muscular bag like structure and partial digestion of food occurs here.
- Glands embedded in the wall of the stomach secrete HCl, mucus and pepsin.
- HCl makes food acidic for the action of pepsin and kills harmful bacterias.
- Mucus protects the wall of the stomach from the action of HCl.
- Pepsin breaks down proteins into simpler forms.
- Food moves into a highly coiled structure called the small intestine.
- The 100% digestion of food occurs in the small intestine.
- Small intestine gains secretion from the liver and pancreas.
- Liver secretes bile juice which makes food alkaline and breaks down large fat globules into smaller fat globules, called emulsified fats.
- Pancreas secrete pancreatic juice which contains, pancreatic lipase, pancreatic amylase and trypsin.
- Pancreatic lipase breaks down emulsified fats into fatty acid and glycerol.
- Pancreatic amylase breaks down starch into simple forms.
- Trypsin breaks down proteins into simple forms.
- Many enzymes are secreted by the wall of the small intestine which finally digest carbohydrates into the simplest sugars, proteins into amino acids and fats into fatty acids and glycerol.
- The digested food is absorbed by the finger-like projections called villi.
- The undigested food enters into the large intestine, and water is absorbed here.
- The undigested food is finally removed out of the body, through anus.
Final Answer
Hence, this is the well labeled diagram of the human digestive system and its explanation.