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The heart and circulation

The heart and Circulation

Heart detail

• The heart is divided into 4 distinct chambers
• Upper chamber is called Atria (Left Atrium & Right Atrium)
• Lower chamber is called Ventricles ( Left Ventricle & Right ventricle)
• 4 main blood vessels linked to the heart:
• Artery (Pulmonary Artery & Aorta Largest Artery)
• Veins (Vena Cava largest vein & pulmonary veins)
• Pulmonary tells you it travels to and from the lungs
• Heart has 4 sets of Valves

Slide 4

• Heart pumps blood to the lungs to get oxygenated
• Then the oxygenated blood returns to the heart
• Heart will them pump the oxygenated blood to every part of the body
• Then the de-oxygenated blood returns back to the heart

Heart Function in details

• 1) Red blood cells arrive through the Vena carva and enters the Right Atrium
• 2) When right atrium fills up with blood it then contract causing the blood to escape through the valves into the Right Ventricle, then the Right Atrium relaxes.
• 3) Then the ventricles wall contract causing the valves to shut, then the force pushes the valves to open into the pulmonary artery, then ventricle relaxes
• 4) Blood exits through the pulmonary artery away from the hear into the lungs where it is oxygenated .
• 5) The oxygenated blood travels along the pulmonary veins
• 6) The atrium walls contract causing the blood to open the valves into the left ventricle
• 7) the left ventricle contacts causing the valves to open and the blood enters through the Aorta
• 8) The blood exits through the Aorta into all the parts of the body
• The left ventricles has the thickest walls as more muscle needed to pump blood around the whole body

Components of blood

• Plasma - Transports useful materials to cells & Transport waste materials away from cells
• White blood cell - Changes shape to engulf pathogenes & produces antibodies and antitoxine
• Platelets - helps blood to clot around a wound
• Red blood cells - consists of 280 million of haemogoblin (It contains 4 units - each unites contain iron) It is biconcave for O2 aspiration & Haemogoblin contains iron to carry O2 & no nucleus more space for haemogoblin

Artery and veins

• Arteries always carry blood away from heart
• Usually oxygenated
• Under high pressure
• Thick muscular walls
• Small Lumen
• Veins always carry blood to the heart
• Usually de-oxygenated
• Under low pressure
• Thinner muscular walls
• Valves prevent backflows
• Larger Lumen - help blood flow

Capillaries

• It transports blood to cells from arteries
• Transports waste away from cells to vein
• Walls are one cell thick
• Walls are permeable
• Allows rapid diffusion of substances