Body systems Flashcards
What is digestion?
Digestion is the process of breaking down food into a usable form and making the nutrients available.
What are the parts of the digestive system?
- Mouth
- Oesophagus
- Stomach
- Small intestine
- Large intestine.
Other: Pancreas, Liver.
What is the function of the mouth in the digestive system?
Your teeth break down food and the saliva moistens the food to make it easy to swallow.
What is the function of the oesophagus in the digestive system?
It is a long muscular tube that connects the mouth and stomach and the muscles (bolus) push the food down by contracting and relaxing. This process is called peristalsis.
What is the function of the stomach in the digestive system?
Food is then stored in the stomach for 1-6 hours where the food is turned into a thick, acidic soup. Mechanical digestion occurs as the muscular walls relax and contract, churning the food and mixing it with gastric juice.
What is the function of the small intestine in the digestive system?
A 6 metre long narrow tube with a diameter of 3cm which breaks down food, absorbs the nutrients the body needs, and excretes unnecessary components.
What are the 2 parts of the small intestine and what do they do?
duodenum: tubes from the liver and pancreas deliver chemicals for digestion.
ileum: where the food reaches in the form of very tiny particles that are then absorbed.
What is a villi?
The villi cover the inner lining of the ileum. They are microscopic fingers that increase the surface area available for absorbing nutrients.
What is a capillary?
Within each villus is a tiny blood vessel called the capillary with walls only 1 cell thick, so the nutrients have only a tiny bit to travel into the blood. They transport, blood and nutrients to cells and organs in your body
What is the function of the large intestine in the digestive system?
Is the final section of the digestive tract and is 1.5m long and 6-7cm wide. Water is reabsorbed into the body from what is left of our food and any remaining nutrients.
What is the pancreas?
It is connected to the digestive tract and produces pancreatic juice that contains chemicals that break down carbohydrates, protein and fats.
What is the liver?
The largest internal organ that is responsible for over 500 chemical processes. It produces bile which is a greenish liquid responsible for the mechanical breakdown of fats. It breaks large pieces of fat into tiny pieces.
Define mechanical digestion
Mechanical digestion is a physical change when food is broken down into smaller pieces that happen when you tear and chew things in your mouth.
Define chemical digestion
When the large substances in your food are broken down into simpler chemicals.
How does chemical digestion happen?
It happens when saliva in your mouth and gastric juices in your stomach break down your food.
Why is chemical digestion a chemical change?
This is a chemical change because new substances are made and these new smaller chemicals can be absorbed by the body.
Define respiration as a series of chemical reactions
It is a series of chemical changes that take place in cells to release energy.
Describe the process of respiration
The respiratory system burns oxygen and glucose for energy, and are changed for carbon dioxide. It takes out oxygen from the air you breathe in and passes it into the bloodstream. It also gets rid of carbon dioxide which is a waste product produced by cells.
What are the new substances formed during respiration?
New substances like carbon dioxide and water are formed.
How does the respiration process produce energy?
By combining glucose with oxygen from the air and burning it for energy.
How is respiration a chemical change?
It is a chemical change because new substances like carbon dioxide and water are formed by burning extracted oxygen from the air you breathe in and combining it with glucose.
Explain the process of breathing
Breathing is the physical process of exchanging gases, breathing oxygen in, and breathing carbon dioxide out.
Is breathing a physical or chemical process?
Physical
Outline the main organ in the respiratory system and how it works
The lungs.
When you breathe in, air enters your lungs and oxygen from that air enters your lungs. Carbon dioxide, a waste gas, moves from your blood to your lungs and is breathed out.
