Circulatory System Flashcards
What is the circulatory system?
The circulatory system carries blood and dissolved substances to and from different places in the body.
What are the 3 main types of blood vessels?
Veins, Arteries and Capillaries are the 3 main types of blood vessels.
Veins: Carry Blood towards the heart
Thin Muscle and elastic fibres. Body muscles surround the veins so that when they contract they also squeeze the veins and push the blood along the vessel. The Veins have valves which act to stop blood from going in the wrong direction.
Artery: Carry Blood away from the heart
Thick muscle and elastic fibres. The Thick Muscle can contract to push the blood along and the elastic fibres allows it to stretch under pressure.
Capillary: Links arteries with the veins.
The wall of a capillary is only one cell thick
They exchange materials between the blood and other body cells. The exchange of materials between the blood and the body can only occur through capillaries.
What is in blood vessels?
Red Blood cells, digested food, white blood cells, oxygen, carbon dioxide, plasma, hormones, platelets and waste (Urea).
What are red and white blood cells?
Red: Contain haemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it. Can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries. A biconcave disc that is round and flat without a nucleus. White: There are many different types and all contain a big nucleus. The two main ones are the lymphocytes and the macrophages. Macrophages ‘eat’ and digest micro-organisms. Some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them. Other lymphocytes make antitoxins to break down poisons.
What is platelets and plasma?
Platelets: Platelets are bits of cell broken off larger cells. Platelets produce tiny fibrinogen fibres to form a net. This net trap other blood cells to form a blood clot. Plasma: A straw colored liquid that carries cells and the platelets which help blood clot.
How does the circulatory system and heart work?
- The Circulatory system is a double circulatory system which means it has 2 parts.
• The Right side (Blue) of the system deals with deoxygenated blood
• The Left side (Red) of the system deals with oxygenated blood.
How the Heart Works -
There are two main phases of action:
1. Heart muscle relaxes while the heart fills with blood
2. Heart muscle contracts and pumps blood forward
There are 4 chamber of the heart,
• The right atrium and below it is the right ventricle.
• The left atrium and below it is the left ventricle.
How does the blood flow through the heart?
The dexoygenated blood comes into the right atrium through the superior vena cava and then the tricuspid valve opens into the right atrium and then the dexogynated blood goes through the pulmonary artery and out into the left lung where the deoxygenated blood becomes oxygenated then that blood comes through the heart again through the aortic valve and is pumped out through the rest of the body.
