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www.GOALias.blogspot.comCompare the values you obtained andinsert them in Table 11.1.Table 11.1 Pulse rateS. No. Name1.2.3.4.5.Pulse per minuteVeins are the vessels which carrycarbon dioxide-rich blood from all partsof the body back to the heart. The veinshave thin walls. There are valves presentin veins which allow blood to flow onlytowards the heart.PulmonaryarteryVeinLungsHeartCapillariesPulmonaryveinArteryFig. 11.3 Schematic diagram of circulationI am confused! I have learntthat an artery alwayscarries oxygen-rich blood.Paheli explained that thepulmonary artery carries bloodfrom the heart, so it is called anartery and not a vein. It carriescarbon dioxide-rich blood to thelungs. Pulmonary vein carriesoxygen-rich blood from thelungs to the heart.Refer to Fig. 11.3. Do you see thearteries divide into smaller vessels. Onreaching the tissues, they divide furtherinto extremely thin tubes calledcapillaries. The capillaries join up toform veins which empty into the heart.HeartThe heart is an organ which beatscontinuously to act as a pump for thetransport of blood, which carries othersubstances with it.Imagine a pump working foryears without stopping! Absolutelyimpossible. Yet our heart works like apump non-stop. Let us now learn aboutthe heart.The heart is located in the chestcavity with its lower tip slightly tiltedtowards the left (Fig. 11.1). Hold yourfingers inwards on your palm. That123TRANSPORTATIONIN ANIMALSAND PLANTS123