3 What is the circulatory system? The circulatory system carries blood and dissolvedsubstances to and from different places in the body.The Heart has the job of pumping these things aroundthe body.The Heart pumps blood and substances around thebody in tubes called blood vessels.The Heart and blood vessels together make up theCirculatory System.
4 The Closed Circulatory System Humans have a closed circulatory system, typical of all vertebrates, in which blood is confined to vessels and is distinct from the interstitial fluid.The heart pumps blood into large vessels that branch into smaller ones leading into the organs.Materials are exchanged by diffusion between the blood and the interstitial fluid bathing the cells.
5 The Cardiovascular System Three Major Elements – Heart, Blood Vessels, & Blood1. The Heart- cardiac muscle tissuehighly interconnected cellsfour chambersRight atriumRight ventricleLeft atriumLeft ventricle
6 Our circulatory system is a double circulatory system. It has two parts.LungsBody cellsthe right side of the system deals with deoxygenated blood.the left side of the systemdeals with oxygenated blood.
7 Pathway of the blood Bicuspid Valve Left Ventricle Superior Vena CavaRight AtriumTricuspid ValveRight VentriclePulmonary Semi lunar ValveLungsPulmonary VeinBicuspid ValveLeft VentricleAortic Semilunar ValveAortaTo the bodies organs & cells
8 How does the Heart work? blood from the body STEP ONEblood from the bodyblood from the lungsThe heart beat begins when theheart muscles relax and bloodflows into the atria.
9 the valves open to allow blood into the ventricles. How does the Heart work?STEP TWOThe atria then contract andthe valves open to allow bloodinto the ventricles.
10 The cycle then repeats itself. How does the Heart work?STEP THREEThe valves close to stop bloodflowing backwards.The ventricles contract forcingthe blood to leave the heart.At the same time, the atria arerelaxing and once again filling withblood.The cycle then repeats itself.
11 Blood from the heart gets around the body through blood vessels There are 3 types of blood vesselsa. ARTERYb VEINc CAPILLARY
12 Arteries carry blood away from the heart. The ARTERYArteries carry blood away from the heart.the elastic fibres allow the artery to stretch under pressurethe thick muscle can contract to push the blood along.thick muscle and elastic fibres
13 Veins carry blood towards from the heart. The VEINVeins carry blood towards from the heart.veins have valves which act to stop the blood from going in the wrong direction.thin muscle and elastic fibresbody muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel.
14 The CAPILLARY Capillaries link Arteries with Veins they exchange materials between the blood and other body cells.the wall of a capillaryis only one cell thickThe exchange of materials between the blood and the body can only occur through capillaries.
15 The CAPILLARY artery vein body cell A collection of capillaries is known as a capillary bed.arteryveincapillariesbody cell
16 what’s in BLOOD digested food red blood cells white blood cells oxygen waste (urea)plateletscarbon dioxidehormonesplasma
17 The Bloodwhite blood cellred blood cellplasmaplatelets
18 Red Blood Cellscontain haemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it.a biconcave disc that is round and flat without a nucleuscan change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries.
19 White Blood Cellsthere 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.
20 Platelets Platelets are bits of cell broken off larger cells. Platelets produce tiny fibrinogen fibres to form a net. This net traps other blood cells to form a blood clot.
21 PlasmaIt also contains useful things like;carbon dioxideglucoseamino acidsproteinsmineralsvitaminshormoneswaste materialslike urea.A straw-coloured liquid that carries the cells and the platelets which help blood clot.