Learn: Digestive System and Digestion

Welcome!Today we'll learn about the digestive system and the process of digestion. This topic is all about how our bodies break down food into smaller, absorbable molecules. Let's dive in!

What is Digestion?Digestion is the process of breaking down large, insoluble food molecules into smaller, soluble molecules that can be absorbed into the bloodstream. It ensures our body gets the nutrients it needs for energy, growth, and repair.

Why Do We Need Digestion?Our bodies cannot directly use the food we eat unless it's broken down into smaller molecules. For example, proteins must be broken into amino acids, and starch must be converted into glucose for energy. Without digestion, our cells wouldn't get the nutrients they need to function.

Digestive EnzymesDuring digestion, special proteins called enzymes help break down food molecules. Different enzymes work on different types of nutrients:Carbohydrase: Breaks carbohydrates into sugars like glucose.Protease: Breaks proteins into amino acids.Lipase: Breaks fats into fatty acids and glycerol.

The Digestive SystemThe digestive system is a series of organs that work together to digest food. Key parts include:Mouth: Chews food and mixes it with saliva.Oesophagus: A muscular tube that pushes food to the stomach.Stomach: Produces acid and enzymes to help break down food.Small intestine: Absorbs nutrients into the bloodstream.Large intestine: Absorbs water and forms waste.

PeristalsisPeristalsis is the wave-like muscle contractions that move food through the digestive system. It happens in the oesophagus, stomach, and intestines. This ensures food keeps moving in the right direction.

Bile and Its FunctionBile is a substance produced by the liver and stored in the gall bladder. It helps digest fats by breaking them into smaller droplets, making it easier for lipase to work.

Absorption in the Small IntestineThe small intestine absorbs nutrients from digested food. It has tiny finger-like structures called villi, which increase the surface area for absorption. Villi contain blood vessels that carry nutrients to the rest of the body.

Review Time!Great work! You've learned about digestion, digestive enzymes, and the structure and function of the digestive system. Now let's test your understanding with a few questions.