Digestion and Absorbption

What is Digestion

Digestion is a process in which large, Complex and insoluble food molecules are converted into smaller, simpler and soluble one.

Types of Digestion and their description

Their are two types of digestions one Physical and the other chemical. The list below shows the difference between physical and chemical digestion

Physical	Chemical
food is break down to increase surface area	Food is break down by the actions of Enzymes

What are two parts used in digestion, in which parts the food enters and which enzymes are present in organ and what they do

There are two parts of used in digestion one allimentary canals and the Digestive glands. The allimentary canals are the parts in which food passes while digestive glands are parts which produces enzymes but food does not passes through it.

The food is first chewed up in mouth and saliva which is 90% water and 10% Amylase break is further. (Note : The teeth make it into smaller pieces to increase surface area while Amylase converts starch into maltose.)The food is converted to Bolus (A ball like structure)

Then, it travels in a long tube called esophagus. The esophagus is also known as gullet or food pipe. The food is broken down into smaller pieces to increase surface area (physical digestion) through peristalses (wavy like movement when the esophagus contracts and relaxes.

It reaches to the stomach where the HCl kills Pathogens (bacteria) and makes an acidic environment for pepsin. In simple it converts Pepsinogens to pepsin. Then pepsin converts protein to polypeptides. Then, the food is made into Chyme (A paste like thing).

Then, the food finally enters into small intestine where Absorbption is taken place and Digestion is completed. Here, Bile from liver and pancreatic juices from pancreas are produced. Bile emulsify fats (Emulsification is similar to physical digestion). Amylase converts starch to maltose, Protease convert polypeptides to peptides and lipase converts fats into fatty acids and glycerol. Then small intestine produces peptidases, sucrase, Maltase and lactase. Peptidases convert peptides to amino acids, Sucrase convert sucrose to glucose and fructose, Maltase convert maltose to glucose, Finally, ;lactase convert lactose to glucose and galactose

Absorbption and diffusion

As the food is converted in its simplest form and gets absorb by our intestinal walls where it enters villi (A finger like projection

Villi has three properties. One is that it has thin wall. Second, it is richly supplied with blood capillaries. Last, It has a large surface area. Then, in Villi there are tiny villi’s known as microvilli which is richly supplied with blood capillaries and has high concentration of fats also. Her the food is diffused into the blood and is supplied to other parts of body.

Diffusion means random movement of particles from high concentration to low concentration down the concentration gradient