4 Function of the Digestive System

Question 1

Ingestion

Answer 1

• Intake of nutrients and water into the digestive tract
• The process of taking food, drink or another substance into the body by placing it into the oral cavity

Question 2

Digestion

Answer 2

• Complex process of turning the food into nutrients, which can move from the digestive organs into the blood
• The body uses these for energy, growth and cell repair
• Mechanical - Physically breaks down food in the mouth by chewing into smaller pieces. Teeth used as incisors to tear and cut food
• Chemical Digestion - Uses enzymes to chemically break down complex food substances into their simplest form, e.g Starch to amylase to maltose.

Question 3

Absorption

Answer 3

• The process by which nutrients pass through the walls of the intestine into the bloodstream or lymphatic system for distribution to the cells.
• Villi increase surface area for absorption
• Water is absorbed mainly in the large intestine

Question 4

Excretion

Answer 4

• The process of expelling residues from food that the body that has not passed through the cells.
• Removal of ‘metabolic waste’ from the body
• A solid waste (faeces) is created from material not absorbed, and is stored in the rectum to be excreted via the anus.
• ‘Defection’ occurs