22 Aug Hour 12 Human Digestive System Part II
HUMAN DIGESTIVE SYSTEM
- Small intestines are roughly 7 meters long
- Lining of intestine walls has finger-like projections called “Villi”, to increase surface area.
- The villi have microvilli which further increases surface area for absorption.
DIGESTION IN SMALL INTESTINE
3 Juices reach in Duodenum part of small intestine viz. –
- 1. Bile from Liver
- Pancreatic Juice from Pancreas
- Succus Entericus from Intestinal Glands
- Bile “Emulsifies” fat.
- Pancreatic Juice contains enzymes like ‘Trypsin’ for partially digesting proteins, ‘Amylase’ for Starch and ‘Lipase’ for fat.
Succus Entericus contains an array of enzymes which completes the process of digestion of all the components of food.
Directly affects digestion by producing bile, which is stored in Gall Bladder.
- Bile helps digest fat by emulsifying it.
- Filters out toxins and waste including drugs and alcohol
A leaf like structure, present below the stomach.
- Produces digestive enzymes to digest fats, carbohydrates and proteins.
- Regulates blood sugar by producing insulin and glucagon
ABSORPTION OF FOOD
- Digested food gets absorbed in Small Intestine and enters blood vessels and lymphatic vessels.
- After digestion, Proteins are broken down in Amino Acids ; Starch and other carbohydrates in to Simple Sugars and enter Blood Capillaries.
- Fats are broken down in to Fatty Acids and Glycerol which enter the Lymphatic Vessels.
- Villi and Microvilli make the process of ABSORPTION effective by increasing the absorptive surface area.
- About 5 feet long
- Accepts what small intestines don’t absorb.
- Absorption of water and minerals take place.
- Rectum, last part of large intestine, holds faeces before it is expelled out through anus.
- Absorbs more water
- Concentrate wastes
- The process of removal of undigested and unabsorbed components of food from the Rectum through Anus is called as Egestion or Defaecation.
- It involves the peristaltic movement of all the organs of digestive system.