Learn: The Digestive System in Humans

Welcome!Today we'll explore the human digestive system. We'll understand how food is broken down, absorbed, and used by the body. Let's get started!

What is Digestion?Digestion is the process where large, insoluble food molecules are broken down into smaller, soluble molecules that can be absorbed into the bloodstream. This ensures your body gets the nutrients it needs to function properly.

Why is Digestion Important?Without digestion, nutrients like glucose, amino acids, and fatty acids couldn't be absorbed by the body. These nutrients provide energy, help build and repair tissues, and regulate bodily functions.

Digestive EnzymesCarbohydrase breaks starch into glucose. Protease breaks proteins into amino acids. Lipase breaks fats into fatty acids and glycerol. These enzymes work best under specific pH conditions found in different parts of the digestive system.

The Human Digestive SystemThe digestive system includes organs like the mouth, oesophagus, stomach, small intestine, and large intestine. Each organ plays a specific role in the digestion and absorption of food.

How Digestion WorksIn the mouth, food is mechanically broken down by chewing and mixed with saliva containing amylase. It then travels down the oesophagus to the stomach, where protease and hydrochloric acid break down proteins. In the small intestine, bile emulsifies fats, and enzymes like lipase complete digestion.

Absorption in the Small IntestineThe small intestine absorbs nutrients into the bloodstream. Its inner walls are lined with villi, which increase the surface area for absorption. Villi contain blood and lymph vessels to transport nutrients.

PeristalsisPeristalsis is the wave-like contraction of muscles in the oesophagus, stomach, and intestines that moves food along the digestive system. This ensures food doesn't get stuck and continues towards absorption and excretion.

Review Time!Great work! You've learned about digestion, digestive enzymes, and the structure and function of the digestive system. Let’s review with a few questions.