Lesson 6 - Digestion And Digestive System Flashcards
What are the five stages of digestion
Ingestion
Digestion
Absorption
Assimilation
Egestion
What is mechanical digestion
Happens primarily in the mouth
Increases surface area
Also happens in stomach
What is chemical digestion
Starts in mouth
Continues in the stomach and small intestine
It involves breaking the chemical bonds in the large molecules resulting in the formation of smaller molecules
What are enzymes responsible for
Chemical digestion
What are the 3 main enzymes
Amylase
Protease
Lipase
What does amylase do
Breaks down carbs into sugar molecules
What does protease do
Breaks down protein into amino acid molecules
What does lipase do
Breaks down fats into fatty acids and glycerol
What happens in the mouth
Food is chewed
Teeth cut up food into smaller pieces
This increases surface area
Saliva is also added
This contains amylase to digest starch
What is the oesophagus
Tube that carries food from mouth to stomach
What does the oesophagus have
Muscular walls
What happens in the stomach
Mechanical and chemical digestion
What do the walls of the stomach produce
Hydraulic acid
What does this ensure
Any bacteria on our food is killed off
What are features the small intestine have that increase fee surface area
- it’s very long
- walls are folded
- walls are covered in villi
What is ingestion
Food is taken in through the mouth
What is digestion
Food is broken down into soluble substances
Starts in the mouth with chemical digestion of starch
And continues in the stomach and small intestine
What is absorption
The soluble products are absorbed into the bloodstream
And transported around the body
This happens in a part of the small intestine called the ileum
Assimilation
The soluble products of digestion are taken into the cells where they’re used
What is egestion
Removal of waste products via the anus
