What are the types of digestion?

1. Mechanical digestion:

- Physical breakdown of food into smaller particles by chewing, grinding, and churning.

- Occurs in the mouth (mastication) and stomach (churning).

2. Chemical digestion:

- Breakdown of complex food molecules into simpler substances through the action of enzymes.

- Occurs in the mouth, stomach, and small intestine.

a) Carbohydrate digestion:

- Begins in the mouth with salivary amylase, which breaks down starches into simpler sugars.

- Continues in the small intestine with pancreatic amylase, which further breaks down starches and disaccharides into monosaccharides like glucose, fructose, and galactose.

b) Protein digestion:

- Begins in the stomach with pepsin, which breaks down proteins into smaller peptides.

- Continues in the small intestine with pancreatic proteases such as trypsin, chymotrypsin, and elastase, which further break down peptides into individual amino acids.

c) Fat digestion:

- Begins in the stomach with gastric lipase, which breaks down some dietary fats into fatty acids and glycerol.

- Continues in the small intestine with pancreatic lipase and bile salts. Bile salts emulsify fats, increasing their surface area for lipase to break them down into fatty acids and glycerol.

3. Absorption:

- Process by which digested nutrients are absorbed into the bloodstream.

- Occurs primarily in the small intestine, where the inner lining (mucosa) is covered in tiny finger-like projections called villi that increase the surface area for absorption.

After absorption, nutrients are transported throughout the body by the circulatory system to provide energy and building blocks for various metabolic processes.