21-1The Heart & The Blood PipesOur heart is one of the hardestworking organs in our body. It isthat organ which beats many timeseach and every second of our life.They do their work and make surethat we are able to live and enjoylife too. The moment our heart stops work- ing. We are dead. In this chapter, let us learn all about this important organ in our body. The heart works along with a complicated system of pipes that runs through our body.
21-2 HeartThe heart is a precious organ inside the chestslightly to the right of the midline. It is aboutthe size of the person’s closed fist and the heartbeats without a break throughout the life of the heartthe person.The heart is like an automatic pump. Made ofspecial muscle, its walls first squeeze the bloodout of its pipes. It then waits for a while forblood to rush into it from distant parts of the the heartbody and from the lungs. Then again, it pipessqueezes the blood out, pumps in blood fromother parts and the cycle continues. What is the pulse? Each time the heart beats, the wave A hard working pump is carried to the last parts of the Imagine how hard working the blood pipes and is called pulse. The heart is? Whenever the heart pulse just like the heart should also beats, it is pumping blood. The record sixty to eighty per minute. heart beats, or in other wordsUsually we measure the pulse in the pipe in the wrist on the squeezes the blood out sixty toside of the thumb where it can be felt easily. eighty times every minute! When exercising or when we have feverEach time the heart squeezes, about eighty to hundred ml of and some diseases, the heart mayblood is sent out. Since each of us has nearly eighty ml of have to squeeze much more oftenblood for each kilo of weight we can easily see that almost all to meet the higher oxygen andthe blood is passed through the heart and lungs at least once other demands of the body.a minute Rush a Bleeding Child to Hospital An average adult with sixty kilo weight will have 80 ml x 60kgs i.e. 4800 ml of blood or nearly five litres of blood. A child with ten kilo weight will have only 80 ml x 10 kgs, that is less than one litre of blood. Hence, in an accident where an adult and a child are bleeding, the child is more likely to die from losing just half litre loss of blood. Rush children with bleeding to the hospital!
21-3 How our heart works Our heart has four compartments. Two of the compartments (the right side of the heart) receive blood from differ- ent parts of the body and pump it to the lungs where it gets fresh oxygen. From the lungs, the blood with fresh oxygen goes back to the heart (the left side) and from there it gets pumped to different parts of the body. It works some- thing like this: The first (I) is called the Right Atrium(at-ri- yum). This is where blood is brought from all parts of the body AORTA through the Vena Cava Takes Fresh (or big veins). Blood to rest of Body From here , the blood flows to the second compartment (II), the Right Ventricle. The blood gets squeezed out to the lungs from here. The lungs put fresh oxygen into the blood and now send it to the left side of the heart (Part III).It first goes to the left atrium (Part III) and then to the left ventricle (Part IV) where it gets pumpedto other parts of the body.A large artery called the aorta takes the fresh blood from the left ventricle (Part IV) for giving it to allparts of the body.
21-4 Parts of the Heart Heart Valves The valves of the heart make sure that Repairing Heart Valves blood flows down only in one direction People whose valves are in the pipe. damaged permanently because of repeated sore Damaged Valves throat infections or by birth, Sometimes these valves can get dam- may need operation to repair aged. Some children are born with the valves or to replace them damaged valves. Sometimes, repeated with artificial ones. Replac- throat infections can damage the valves. ing heart valves is more ex- The heart has to beat more and the load pensive than operating the on the heart increases. heart to repair them.If the heart does not work well , the lungs get full of water because there is a backlog that cannot bepushed out. Such patients get breathless very easily and if the illness gets serious, they cannot breatheproperly even while sitting or lying down. Gradually, the heart weakens and could cause heart fail-ure.Pacemaker & ECGPacemaker (pase-may-ker) is a part of the heart. It sends weak currents at regular intervals to help the heartsqueeze and maintain the regular beating rhythm. In case of a heart attack affecting the area of the pacemaker, theregular beat may be lost. Unless such patients get a artificial pacemaker, they are not likely to survive long.ECG Our Heart Can Change Its Beat What are heart attacks?Does our heart not beat faster when we are From the heart, the aorta collects blood to give toangry or scared or anxious or even very ex- other parts through a sys-cited or happy? Nerve connections to the brain tem of blood pipes.make the pacemaker beat at a faster or a slowerpace. The body prepares to react and face emer- But like how drain pipe orgencies when it senses strong feelings. It gets water pipes in our own ready to give more food and oxy- homes get blocked with gen and so pumps faster to get the dirt, blood pipes can also blood moving. get blocked. Don’t we feel our heart beating Older people and people hard when we do some exercise? who eat very oily and greasy food could have their Every time the body exercises and blood pipes blocked. Those who take meat, eggs there is more blood coming back to and fried things very often are more likely to havethe heart, the heart muscle stretches out wider. this problem.In response to the stretch, it tends to beatstronger so that instead of the normal 80 to If a pipe is completely blocked, blood and hence100 ml per squeeze, it now throws out 100 to oxygen cannot reach one or more parts of the heart.150 ml per squeeze. But this cannot happen This is what is meant by a heart attack. If too largefor long. If such conditions continue too long, an area is affected, the heart may no longer be ableit shows on the performance of the heart and it to squeeze out blood properly and heart may failmay fail. completely. The person would die.
21-5 The Blood PipesPipes throughout the body carry blood from and to the heart. One set of pipes carries the blood tothe heart (veins) and another set of pipes (arteries) takes it away from the heart. Another set ofpipes that are very thin and allow things to pass out from their walls are called capillaries. 1. Arteries 2. VeinsAny pipe that carries blood Veins carry blood back to theaway from the heart is called heart from the diffrent parts ofan artery. The biggest artery is the body. The process is oppsite Network of Veins & Arteriesthe Aorta, that comes directly are like roads on which the from the arteries. Here, tiny cap-from the heart. blood travels carrying illaries join together to form oxygen & food for all body veins.Most organs like the brain, parts!heart, liver, kidneys and Small narrow veins, startingstomach have one or more ar- from far off capillaries, keep join-teries supplying blood to ing into larger ones. Blood hasthem. to be brought to the heart both from the top of the body andThe walls of these pipes are from the bottom.thick and strong so that theycan take the force of the push Veins from the upper part of themade by the heart. body end in the Superior Vena Cava and those from the lowerEach artery keeps giving rise parts of the body end in the Infe-to smaller and smaller rior Vena Cava. Both these veinsbranches until they become pour blood into the Right Atriumvery narrow and the wall (compartment I) of the heart.thickness also lessens. Thesmallest arteries end in a loose Veins have thin walls and henceweb of pipes that have very the blood can be seen throughthin walls through which them. As they have no heart likemany substances can pass pump that keeps pushing thethrough. These webs are blood, there is a chance that thecalled capillaries and allow blood may flow back. Veins haveoxygen and other small nutri- valves that allow the flow onlyents to pass through its walls. towards the heart. 3. Capillaries : The Smallest Blood Pipes The smallest arteries end in a loose web of pipes that have very thin walls. Through these walls many substances can pass leave and also enter. These webs are called capillaries and allow oxygen and other small nutrients to pass through its walls. For example, such capillaries in the brain or in the leg muscles will allow the oxygen to slip out and be available to the organ there. At the same time, the thin walls allow the waste carbon dioxide to slip into the blood. This is carried back to the heart through the veins. Form the heart they go to the lungs and oxygen is put into them.
21-6 Learning To Find Our Arteries & VeinsFinding Arteries Finding VeinsTake your friend’s hand. Lightlypress your middle three fingers – Tie a thin string or anot hard – against the bone just shoelace just aboveabove the wrist on the side of the your elbow. It should bethumb. Turn the hand down and loose enough to allowlet the wrist hang loose. Do you your little finger to passfeel the throb of the artery? Count through. Soon you willit. This is the artery that brings blood from the heart to the hand. see the veins of your forearm and hand very Another artery that can be easily felt clearly. Why do they takes blood to the brain. For this, look blue or green when look straight and try to feel the hard the blood inside them is cartilage of the voice box in your red in colour? neck. Reach its upper end and go one finger width above. Now take your Block the upper end of finger to the side of the neck - one a small vein, and side at a time - till it reaches the mus- squeeze out the bloodcle. Press lightly. You will feel the throb of the artery. In uncon- to the lower end. Doesscious people, if this artery is not throbbing, it tells us that blood the blood fill up againis no longer going to the brain and the person may have died very quickly? Nowalready! block it at the lower end and squeeze it the upper way? Does the blood fill up asYou may feel another artery ‘one in the middle of the elbow. Try quickly? Why?to feel other arteries in the body. BLOOD PRESSURE What is What is the Blood Pressure? “Normal Pressure”? In normal people of young age,The heart has to pump blood the blood pressure ranges fromnon-stop every single second 100 to 140 mm of Hg (mercury)as it has to reach food for the when the heart is squeezingbody (oxygen, glucose and (called systolic BP) and betweenmany things) from the head 60 and 90 mm of Hg when theto the toes. If blood fails to reach heart is relaxing (also calledit would would mean certain diastolic BP).death. This is because the brain cannot stay without oxygen formore than three minutes while the heart muscles themselves would It is the pressure in the arteriesdie in less than five minutes. Therefore it is crucial that the heart that the heart has to overcome tomakes sure blood reaches till the very last and the very smallest get the blood across. The highercapillary. the pressure in the arteries, the stronger the heart has to pump.To do this, it will require some pressure to push the blood In old age, and in those who havethrough these pipes. Some ‘pressure’ or ‘tension’ has to be high levels of cholesterol, themaintained by the arteries so that the blood reaches unto walls of the pipe become rigidthe farthest capillaries. This tension or pressure is called and hard. This causes the pres-blood pressure. sure in the blood pipes to rise.
21-7 High B.P & Low B.PHigh Blood Pressure Low Blood PressureIf the blood pressure is above 160 mm Hg while the On the other hand, blood pressureheart is squeezing and above 95 mm Hg when resting below 100 mm Hg while the heart is(we measure it early morning for three days continously), squeezing, and below 60 mm Hgthen we call it as hypertension or high blood pres- when it is relaxing is also not normal.sure. But low blood pressure is not a dis- ease by itself unlike high blood pres-The term Hypertension simply means more tension (or sure.pressure) in the wall of the arteries. It has nothing todo with mental tension, though also, that can contrib- Whenever low blood pressure is de-ute to high blood pressure! High B.P may be due to tected, it is a sign of an underlyingsome kidney diseases, but usually we cannot find any illness that must be treated to raiseother disease with it. the blood pressure back to normal. Look for any cause that may have Treating High B.P caused bleeding : like accidents, frac-Pumping blood at pressures above 160/95 mm Hg results tures, piles, childbirth, etc. It may alsoin the heart getting little rest and hence getting tired. High be the effect of severe loss of water –blood pressure can cause heart disease and later heart dehydration – that may happen infailure. It can also lead to some artery in the brain or diarrhoea or burns. People with lowanother part of the body to burst out and cause bleed- nutrition levels and with mental de-ing. Less salt in the diet and good exercise may prevent pression are also found to have bloodone from taking medicines altogether. pressures below normal. Learn to Measure Blood Pressure Find your friend’s blood pressure by using a blood pressure machine. Go Step By Step 1 Get familiar with the parts of the BP machine like cuff, tube, rubber bulb, valve etc. Also get familiar with the stethoscope, its earpieces, tube, diaphragm and bell. 2 Wrap the cuff of the blood pressure machine above your friend’s elbow, taking care that the rubber cuff covers the front of the elbow. 3 Pump the rubber bulb after closing its valve while ob serving the meter (gauge). Keep pumping the bulb until the meter shows 200 mm Hg. 4 Keeping the diaphragm of the stethoscope on the front of the elbow – a little towards the inner side – slowly start releasing the cuff by opening the valve of the rubber bulb. 5 Note the meter reading – say ‘X’ – when you start hearing the regular beat of the heart (or pulse). 6 Once again, note the meter reading when the sound can no longer be held – say ‘Y’. 7 The first is the pressure when the heart is squeezing and the second reading tells us the pressure when the heart is at rest. Write your friend’s blood pressure as X / Y mm Hg. Isn’t it simple?
21-8 Know the Answers The Heart & Blood Pipesa. Please Mark if “right” or “wrong”:1. The normal pulse rate is between 18 and 20 per minute.2. A child with 10 kilo weight will have 80 ml X 10 kilo or 800 ml of blood in the body.3. Blood from the legs reaches the left side of the heart before going to the lungs.4. Our heart beats slower and harder when we exercise.5. The arteries carry blood with oxygen and take them to far off parts of the body.6. The veins carry blood from the heart to the lungs.7. Capillaries are small nerves that carry blood.b. Please fill in the blanks:1. Normal B.P ranges from _____ to _______ / ________ to ________ mm Hg.2. Arteries end in a web of small tubes called ________________.3. The biggest artery is called ___________.4. The blood goes from Chamber ____ to Chamber _____ before going to the lungs. From the lungs it comes to Chamber ______ to Chamber _____ from where it is pumped out to the rest of the body.
21-9 HEART DISEASES heart valves Mainly three common heart diseases need to be kept in mind. They are: 1. Rheumatic Heart Disease (RHD) 2. Heart Failure 3. Heart Attack 1. Rheumatic Heart Disease (RHD) RHD is a common heart problem in our place. Caused by bacteria, the disease spoils the valves of the heart. The opening of the valves becomes so small that they block the blood being pumped. Or, the valves have started leaking and the blood instead of getting pumped out, comes back into the chamber (II or IV).What Happens In RHD? Sore Throats Can DamageOnce the valves of the heart have been dam- Heart Valves In Childrenaged, they may worsen with every new at- RHD is basically caused by bacteria that alsotack of the sore throat bacteria. If valves are cause sore throat in children and youngdamaged, the blood is unable to be pumped adults. While the body tries to make antibod-out of the heart and hence a backlog keeps ies against the germ, by mistake the anitibodiescollecting. This causes the heart to increase attack the person’s own heart valves or herin size so that it has problems beating prop- joints.erly. This illness starts with what we call RheumaticThe blood also gets stuck in veins of the (Ryoo- ma-tik) Fever in which we have alungs, so that water collects in the lungs and history of sore throat, joint swell-hence oxygen cannot be absorbed. If the ing and high heart rate (pulse). Ifheart disease is serious, RHD patients feel not treated quickly with antibioticsweak, have a bulged out chest on the left like PENICILLIN,side, may feel bad palpitations and get blue. COTRIMOXAZOLE OR DOXYCYCLINE,As the heart has problems in beating, they the illness may worsen and go on to damagemay be seen with swelling of legs and face the heart valves. Highest possible doses of AS-and ultimately die of heart failure. PIRIN – as much as 3 to 6 tablets four times a day with food - are also allowed during the at- tack for Rheumatic Fever. Treating RHD The RHD keeps worsening if the person gets sore throat repeatedly. It is advised that such patients should get Injection Penicillin every month from a doctor, or take COTRIMOXAZOLE daily until five years of the last attack OR till the person becomes 20 years of age, whichever is later. It is rare to see the germ troubling people beyond this age, although the effect on the heart will be there for life. Once RHD has affected the heart, regular treatment from a doctor is needed to avoid further strain on the heart. Any load of pregnancy, an operation or even something simple like getting a tooth removed can put the life of a RHD patient in danger. Persons’ with RHD should avoid getting pregnant and inform the surgeon/doctor about RHD before operation is performed. Valve damage can be operated upon or by replacing the defective valves with artificial valves, but the treatment is costly and available only in very big hospitals.
21-10 2. Heart AttackThe term means that there is a sudden blocking of the blood supply to aportion of the heart and it has stopped functioning properly. Seen in deathscenes in many films, the signals are known to many : · sudden squeezing pain in the chest continuing for more than half an hour · pain spreading to the left arm or neck · feeling of “ end of this world,” · cold sweat on the forehead.Who Gets Heart Attacks ? Why Heart Attacks Happen?People who get heart attacks are usually be- It is mainly because of a clot blocking one or more of the threeyond 45 years of age, but not always. Many arteries supplying blood to the heart. Until the blood supplywould have been on treatment for high B.P. can be arranged from the other arteries, some parts of heartor for heart disease due to repeated pain in muscle get no oxygen and pain a lot.the heart (that lasts for a few minute at a timeand worsens with exertion). Yet, in many the If a large part of the heart muscle is affected, the heart mayillness is a first ‘attack’ on the heart. not be able to pump sufficient amount of blood. In such cases, the heart fails and the person may even die. What To Do In Heart Attacks ? Refer to a hospital immediately any such patient that you suspect has suffered a HEART ATTACK ! But give an ASPIRIN tablet with something to eat before you send her. It can make the difference between living and dying as ASPIRIN decreases the ability of blood to clot. 3. Heart Failure The heart may fail if there is too much of pressure in the arteries to pump across – as in high B.P. - or if there is too much to pump that the heart muscles cannot cope. This is what is called Heart Failure. It may also hap- pen if a Heart Attack (see above) damages too large a part of the heart muscle that it cannot pump effectively. Heart failure of the Left side of the heart causes Heart Failure of the Right side may cause breathlessness (that may worsen to such a level swelling of the legs and face. The liver also that it is not possible to lie down also), pain in the enlarges to press on the stomach, and the chest and dry cough with a wheeze. If severe, blood patient feels heavy in the stomach. may be thrown out with cough.The only way to help the heart is to help improve the underlying reason for heart failure. Loweringthe blood pressure and decreasing fluids helps, but under the monitoring eyes of a doctor. RHDcan be corrected by heart operation, but has its own problems.Where nothing much can be done to help, decreasing the activity to match the heart’s capacity is the onlyway to a longer life. Refer any patient to a doctor for regular, long term treatment of s/he shows signs of heart failure
21-11 Know the Answers The Heart & Heart Diseasesa. Please Fill in the blanks:1. Germs that cause sore throat in children may be responsible for a disease of the ________ of the heart. This is called ____________ Heart Disease.2. Children with RHD should be given germ killer medicines regularly until ______ years og age.3. Signs of serious RHD are _______________, ______________ and ____________________.4. The first aid for heart attack is to give ______________ tablet before sending to a hospital.5. Signs of heart attack seen commonly in people above 45 years of age are ___________, ________________, _____________________ and __________________________.6. Heart Failure of the left side causes _____________ and ____________________.7. Heart failure of the right side causes __________________ and ____________________.