Unit Three: Circulatory System Flashcards
What is the double circulatory systems purpose?
One pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart.
The second one pumps oxygenated blood around all the other organs. The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs.
What are valves for? (In the heart?)
To make sure that blood goes in the right direction (prevents it from flowing backwards)
How does the heart work?
1) Blood flows into the two atria from the vena cava and the pulmonary artery
2) The atria contract, pushing the blood into the ventricles
3) The ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart
4) the blood then flows to the organs through and returns though veins
5) The atria fill again and the whole cycle starts over
Name the sections of the heart:
Pulmonary artery X1 Vena cava X1 Aorta x1 Pulmonary vein x1 Right and left atrium Valve x4 Right and left ventricle
Name the three types of blood vessels and state their function:
Arteries: carry the blood away from the heart
Capillaries: these are involved in the exchange of materials at the tissues
Veins: these carry blood to the heart
What features do arteries have?
They become strong and elastic when the heart pumps the blood out at high pressure
What are capillaries?
What do they branch from?
What are their features?
They carry tiny and carry the blood really close to every cell in the body to exchange substances with them
Capillaries
They have permeable walls- diffusion
They supply food and oxygen and take away waste like CO2
What do veins do?
Take blood back to the heart
What do red blood cells do?
What are their features?
They carry oxygen from the lungs to all the cells in the body
They have a biconcave shape-large surface area
No nucleus-more room for oxygen
Contains haemoglobin
What do white blood cells do?
Features?
They defend against disease
Can change shape-engulf
Can produce antibodies-fight microorganisms as well as antitoxins
Have a nucleus
What do platelets do?
Features?
Help blood clot
No nucleus
Small fragments of cells
What is plasma?
The liquid that carries everything in your blood (red and white blood cells, glucose and amino acids, CO2, urea, hormones and antibodies and antitoxins
What is artificial blood made from?
A salt solution e.g. saline
What is an artificial heart?
Mechanical devices that are put into a person to pump blood if their own heart fails
Advantage of an artificial heart:
They’re not rejected-the body doesn’t recognise the metals or plastics as foreign
