The circulatory system ismade up of:1. heart- pumps blood around thebody2. blood vessels- network of tubes to carryblood around the body3. blood- a liquid that transportsmaterials around the bodyveinheartartery
HeadLungsDouble circulation:Blood passes through theheart twice in one completecirculation.Systemic circulationfrom heart to rest of bodyand back againPulmonary circulationfrom heart to lungs and backagain+Other partsof bodyVIDEOII
lungsleftatriumrightatriumleftventriclerightventricledigestivesystemrest of bodyPulmonaryarteryPulmonaryveinAorta (artery)Vena cava(vein)Deoxygenatedblood at lowpressureOxygenatedbloodDeoxygenatedbloodOxygenatedblood athigher pressure
ORGANBlood VesselsHEARTArteryVeinCapillariesarteries branchinto network ofcapillaries, whichlie close to thecellsfood and oxygenpass from theblood into the cellscarbon dioxide andother wastesubstances passfrom the cells intothe capillariescapillaries jointogether to form theveins which carryblood back towardsthe heart
The Heartvena cava (vein)right atriumright ventricleleft ventriclemuscleleft atriumaorta(artery)pulmonaryarteryDeoxygenatedblood from thebodyDeoxygenatedblood from thebodyto the lungsto the lungsOxygenated bloodfrom the lungsOxygenated bloodfrom the lungsto the rest of thebody againto the rest of thebody againpulmonaryveinseptum
right atriumright ventricleleft ventriclemuscleleft atriumThe HeartPulmonaryarteryPulmonaryveinAorta (artery)Vena cava(vein)123456789
Why is the left side of the heartthicker than the right?The left ventricle is more muscular so thatit can contract forcefully, to sendoxygenated blood quickly to the rest of thebody.The less muscular right ventricular wallscontract less forcefully. Blood is pumpedout to the lungs at a lower blood pressureso as to allow time for exchange of gasesat the lungs
Arteries, veins and capillariesArteries, veins and capillaries
Watch Video on Blood vesselsIntro to blood vesselshttp://www.youtube.com/watch?v=CjNKbL_-cwA&feature=relatedStructure of blood vesselshttp://www.youtube.com/watch?feature=endscreen&v=3ffSxq9iyB8&NR=1
ArteriesArteriesThick & elastic muscular walls enablesthe vessel to withstand the immensepressure of blood as it is forced out ofthe heart.Dilation & constriction of vessel isbrought about by contraction &relaxation of muscles in the vesselwall.
Semi-lunar valves on our handshttp://www.youtube.com/watch?v=d5DGVLTLPg0
Heart valvesHeart valves Semi-lunar valves in pulmonary artery andSemi-lunar valves in pulmonary artery andaorta.aorta. Bicuspid valve (left side of heart, betweenBicuspid valve (left side of heart, betweenleft atrium and left ventricle)left atrium and left ventricle)TTrricuspid valve (icuspid valve (rright side of heart,ight side of heart,between right atrium and right ventricle)between right atrium and right ventricle)
Differences betweenDifferences betweenArteriesArteriesCarry blood awayfrom heart tolimbs & organs ofbodyCarry redoxygenated bloodThick and elasticmuscular wallsVeinsVeinsReturn bloodfrom tissues backto the heartCarry bluish-reddeoxygenatedbloodWalls are thinner,with less elastic &muscular tissue
Differences betweenDifferences betweenArteriesArteriesInternal valves areabsentElasticity allowsstretching &recoiling of vesselwall, help to pushblood alongVeinsVeinsHave internalvalves along theirlength to preventbackflow of bloodMovement ofblood is assistedby action ofskeletal musclesin the body.
Characteristics ofCharacteristics of CAPILLARIECAPILLARIESSMicroscopic blood vessels foundbetween cells of almost all tissuesWalls are made up of only a singlelayer of greatly flattened cellsWall of vessel is partially permeable
Characteristics ofCharacteristics of CAPILLARIECAPILLARIESSDense network of fine vesselsConnects two types of vesselstogetherFunction: Site of exchange ofsubstances between blood andtissue cells
•Blood plasma and some dissolved food substances are forcedout of the capillary walls by diffusion into the tissue fluid, to thebody cells•Blood flow is slow, to enable exchange of substances to occur
bloodcapillarycarbon dioxide diffuse fromthe cell into the bloodoxygen diffuse from the bloodinto the cellExchange of substances betweencells and bloodO2CO2Body cellsPartiallypermeablemembrane
Describe how is the blood capillaryadapted for its function 1 cell thick capillary wall enables substancesto be exchanged quickly (faster rate ofdiffusion) as the distance between body cellsand blood is shorter. Network of branching capillaries increasessurface area for exchange of substances Size of lumen is that of a red blood cell. Rateof blood flow is slow, giving more time forexchange of substances between blood andtissue cells.
Coronary Heart DiseaseDuring a heart attack, blood flow to aparticular part of the heart may becompletely blockedDue to blocked blood flow, that region ofheart muscles are deprived of oxygen andnutrientsThe heart muscles are damaged anddead.
Causes of Coronary Heart DiseaseDiet rich in cholesterolEmotional stressSmoking
Treatment of Coronary HeartDiseaseAngioplasty (ballooning)Coronary Heart Bypass Grafting
What are the consequences of ahole in the heart? The oxygenated blood on the left side of the heartwill be mixed with the deoxygenated blood on theright side of the heart. Blood pumped out of theheart to the rest of the body through the aorta is notfully oxygenated. Thus less oxygen transported toother parts of the body. As blood from left ventricle is pumped into the rightside of the heart, this will cause an increasedpressure, resulting in enlargement of right side ofheart, overworking the heart.