Circulatory system

• Your pulmonary vein is the only vein that carries oxygenated blood
• Your pulmonary artery is the only artery that carries deoxygenated blood
• The circulatory system is made up of three parts; the heart, the blood, the blood vessels
• The heart is divided into four chambers: two atria and two ventricles.
• Blood carries all materials needed by the body, it also removes waste
• Blood is made up of plasma, red blood cells, white blood cells, and platelets
• Red blood cells are made in the bone marrow
• Red blood cells carry oxygen around our body to give to our cells
• Red blood cells contain haemoglobin
• Red blood cells have a flattened disc (bioncave) shape to increase surface area
• White blood cells help fight pathogens
• White blood cells are bigger than red blood cells
• Platelets are broken up bits of cells that are produced in the bone marrow
• Platelets help our blood clot to prevent bleeding
• If you don't have enough platelets, you might bleed excessively. This condition is known as Haemophilia
• If you have too many platelets, you may form clots in your heart or brain which can cause a heart attack
• There are three types of blood vessels: arteries, veins, and capillaries
• Arteries carry blood away from the heart. The blood is pumped from the heart with a lot of pressure.
• To withstand high pressure, the walls of arteries are thick and elastic. They are protected deep in the body to prevent being cut open
• The artery is depicted on the left and the vein is depicted on the right

  
• Capillaries are a network of vessels that join the arteries and veins
• Capillaries are very small and thin so nutrients from blood can pass through it and into cells that need them.
• Veins carry blood back to the heart. The pressure in the blood has been lost, so veins don't have thick walls like arteries
• The left ventricle is much thicker than the right
• Valves make sure blood is flowing in the right direction
• The heart is made of cardiac muscle which doesn't fatigue
• Cardiac muscle contain a lot of mitochondria because they are continuously contracting and relaxing which requires a lot of energy
• The valve between the right atrium and ventricle is called the tricuspid valve
• The valve between the left atrium and ventricle is called a bicuspid or mitral valve
• The beating sound your heart makes comes from valves closing
• The heartbeat has 3 phases - Atria contract, blood goes to ventricles - ventricles contract, blood to body and lungs - heart relaxes, atria fill with blood
• The circulatory system is a double circuit because blood passes through the heart twice per circuit
• The walls of alveoli and capillaries are only a cell thick and share a membrane
• The total surface area of the alveoli in the lungs is large - somewhere between 70m2 and 90m2
• the alveolus has a moist lining to help dissolve the gases
• Heres some information.

  
• The circulatory system is a double circuit because there are two circuits: pulmonary and systemic
• The right ventricle is the pump for the pulmonary circuit
• The left ventricle is the pump for the systemic circuit