Circulatory System Flashcards
Why do we need the Circulatory System?
• The circulatory system is vital as it is the sole way that nutrients, oxygen and waste products are transported to and from cells
Blood Vessels: Arteries
• Carry oxygenated blood away from the heart, to the body
• Need to be tough to take the high pressure. Cutting an artery is bad news!
Blood Vessels: Veins
• Carry deoxygenated blood back to the heart after it has been taken to cells
• Veins contain valves to stop blood flowing backwards. They need these as they do not have the pressure applied by the heart
Blood Vessels: Capillaries
• The smallest blood vessels. There walls are only one cell thick so that nutrients and waste can get through to and from cells
Parts of The Blood
Red blood cells:
• Carry oxygen around the body.
• Contain a chemical called haemoglobin which has iron in it - this attaches to oxygen
White blood cells:
• Help fight disease as part of the immune system
Platelets:
• Help blood to clot
Plasma:
• Clear, yellowish liquid that carries all the other parts of blood
Blood Has…
- 40,000 white blood cells
* 300 million red blood cells
The Heart
• The pump that gets blood to all the places it is needed
• Our circulatory system is called a double system as it has two totally different circuits - one for oxygenated blood and one for deoxygenated blood
Parts of The Heart: Left Atrium
• Take oxygenated blood from the lungs and pumps it down into the left ventricle
Parts of The Heart: Left Ventricle
- Contracts after the atrium to pump blood out into the body
* This happens in two stages so that blood does not flow backwards
Parts of The Heart: Right Atrium
• Takes deoxygenated blood from the body and pumps it down into the right ventricle
Parts of The Heart: Right Ventricle
- Contracts after the atrium to pump blood out into the lungs
- This happens in two stages so that blood does not flow backwards
