The Heart & The Blood Pipes

Our 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 allabout this important organ in ourbody. The heart works along witha complicated system of pipesthat runs through our body.

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Heart

The 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 ofthe 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 thebody and from the lungs. Then again, itsqueezes the blood out, pumps in blood fromother parts and the cycle continues.

What is the pulse?Each time the heart beats, the waveis carried to the last parts of theblood pipes and is called pulse. Thepulse just like the heart should alsorecord sixty to eighty per minute.

Usually we measure the pulse in the pipe in the wrist on theside of the thumb where it can be felt easily.

Each time the heart squeezes, about eighty to hundred ml ofblood is sent out. Since each of us has nearly eighty ml ofblood for each kilo of weight we can easily see that almost allthe blood is passed through the heart and lungs at least oncea minute

the heart

the heartpipes

A hard working pumpImagine how hard working theheart is? Whenever the heartbeats, it is pumping blood. Theheart beats, or in other wordssqueezes the blood out sixty toeighty times every minute! Whenexercising or when we have feverand some diseases, the heart mayhave to squeeze much more oftento meet the higher oxygen andother demands of the body.

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 ornearly five litres of blood. A child with ten kilo weight will have only 80 ml x 10 kgs, thatis less than one litre of blood.

Hence, in an accident where an adult and a child are bleeding, the child is more likely todie from losing just half litre loss of blood. Rush children with bleeding to the hospital!

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It works some-thing like this:The first (I) is called theRight Atrium(at-ri-yum). This is whereblood is brought from allparts of the bodythrough the Vena Cava(or big veins).

From here , the bloodflows to the secondcompartment (II), theRight Ventricle.

The blood gets squeezedout to the lungs fromhere.

The lungs put freshoxygen into the bloodand now send it to theleft side of the heart (PartIII).

How our heart worksOur heart has fourcompartments.

Two of the compartments(the right side of the heart)receive blood from differ-ent parts of the body andpump it to the lungswhere it gets freshoxygen.

From the lungs, the bloodwith fresh oxygen goesback to the heart (the leftside) and from there itgets pumped to differentparts of the body.

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.

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AORTATakes FreshBlood to rest

of Body

Heart ValvesThe valves of the heart make sure thatblood flows down only in one directionin the pipe.

Damaged ValvesSometimes these valves can get dam-aged. Some children are born withdamaged valves. Sometimes, repeatedthroat infections can damage the valves.The heart has to beat more and the loadon the heart increases.

What are heart attacks?From the heart, the aorta collects blood to give toother parts through a sys-tem of blood pipes.

But like how drain pipe orwater pipes in our ownhomes get blocked withdirt, blood pipes can alsoget blocked.

Older people and peoplewho eat very oily and greasy food could have theirblood pipes blocked. Those who take meat, eggsand fried things very often are more likely to havethis problem.

If a pipe is completely blocked, blood and henceoxygen cannot reach one or more parts of the heart.This is what is meant by a heart attack. If too largean area is affected, the heart may no longer be ableto squeeze out blood properly and heart may failcompletely. The person would die.

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 BeatDoes our heart not beat faster when we areangry or scared or anxious or even very ex-cited or happy? Nerve connections to the brainmake the pacemaker beat at a faster or a slowerpace. The body prepares to react and face emer-gencies when it senses strong feelings. It gets

ready to give more food and oxy-gen and so pumps faster to get theblood moving.

Don’t we feel our heart beatinghard when we do some exercise?Every time the body exercises andthere is more blood coming back to

the heart, the heart muscle stretches out wider.In response to the stretch, it tends to beatstronger so that instead of the normal 80 to100 ml per squeeze, it now throws out 100 to150 ml per squeeze. But this cannot happenfor long. If such conditions continue too long,it shows on the performance of the heart and itmay fail.

Parts of the Heart

Repairing Heart ValvesPeople whose valves aredamaged permanentlybecause of repeated sorethroat infections or by birth,may need operation to repairthe valves or to replace themwith artificial ones. Replac-ing heart valves is more ex-pensive than operating theheart 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.

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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.

3. Capillaries : The Smallest Blood Pipes

The smallest arteries end in a loose web of pipes that have very thin walls. Throughthese walls many substances can pass leave and also enter. These webs are calledcapillaries 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 toslip out and be available to the organ there. At the same time, the thin walls allow thewaste carbon dioxide to slip into the blood. This is carried back to the heart throughthe veins. Form the heart they go to the lungs and oxygen is put into them.

2. VeinsVeins carry blood back to theheart from the diffrent parts ofthe body. The process is oppsitefrom the arteries. Here, tiny cap-illaries join together to formveins.

Small narrow veins, startingfrom far off capillaries, keep join-ing into larger ones. Blood hasto be brought to the heart bothfrom the top of the body andfrom the bottom.

Veins from the upper part of thebody end in the Superior VenaCava and those from the lowerparts of the body end in the Infe-rior Vena Cava. Both these veinspour blood into the Right Atrium(compartment I) of the heart.

Veins have thin walls and hencethe blood can be seen throughthem. As they have no heart likepump that keeps pushing theblood, there is a chance that theblood may flow back. Veins havevalves that allow the flow onlytowards the heart.

1. ArteriesAny pipe that carries bloodaway from the heart is calledan artery. The biggest artery isthe Aorta, that comes directlyfrom the heart.

Most organs like the brain,heart, liver, kidneys andstomach have one or more ar-teries supplying blood tothem.

The walls of these pipes arethick and strong so that theycan take the force of the pushmade by the heart.

Each artery keeps giving riseto smaller and smallerbranches until they becomevery narrow and the wallthickness also lessens. Thesmallest arteries end in a looseweb of pipes that have verythin walls through whichmany substances can passthrough. These webs arecalled capillaries and allowoxygen and other small nutri-ents to pass through its walls.

Network of Veins & Arteriesare like roads on which the

blood travels carryingoxygen & food for all body

parts!

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What isBlood Pressure?

The heart has to pump bloodnon-stop every single secondas it has to reach food for thebody (oxygen, glucose andmany things) from the headto the toes. If blood fails to reachit would would mean certaindeath. This is because the brain cannot stay without oxygen formore than three minutes while the heart muscles themselves woulddie in less than five minutes. Therefore it is crucial that the heartmakes sure blood reaches till the very last and the very smallestcapillary.

To do this, it will require some pressure to push the bloodthrough these pipes. Some ‘pressure’ or ‘tension’ has to bemaintained by the arteries so that the blood reaches untothe farthest capillaries. This tension or pressure is calledblood pressure.

What is the“Normal Pressure”?

In normal people of young age,the blood pressure ranges from100 to 140 mm of Hg (mercury)when the heart is squeezing(called systolic BP) and between60 and 90 mm of Hg when theheart is relaxing (also calleddiastolic BP).

It is the pressure in the arteriesthat the heart has to overcome toget the blood across. The higherthe pressure in the arteries, thestronger the heart has to pump.In old age, and in those who havehigh levels of cholesterol, thewalls of the pipe become rigidand hard. This causes the pres-sure in the blood pipes to rise.

Finding ArteriesTake your friend’s hand. Lightlypress your middle three fingers –not hard – against the bone justabove the wrist on the side of thethumb. Turn the hand down andlet the wrist hang loose. Do youfeel the throb of the artery? Countit. This is the artery that brings blood from the heart to the hand.

Another artery that can be easily felttakes blood to the brain. For this,look straight and try to feel the hardcartilage of the voice box in yourneck. Reach its upper end and go onefinger width above. Now take yourfinger to the side of the neck - oneside at a time - till it reaches the mus-

cle. Press lightly. You will feel the throb of the artery. In uncon-scious people, if this artery is not throbbing, it tells us that bloodis no longer going to the brain and the person may have diedalready!

You may feel another artery ‘one in the middle of the elbow. Tryto feel other arteries in the body.

Finding Veins

Tie a thin string or ashoelace just aboveyour elbow. It should beloose enough to allowyour little finger to passthrough. Soon you willsee the veins of yourforearm and hand veryclearly. Why do theylook blue or green whenthe blood inside them isred in colour?

Block the upper end ofa small vein, andsqueeze out the bloodto the lower end. Doesthe blood fill up againvery quickly? Nowblock it at the lower end and squeeze it theupper way? Does the blood fill up asquickly? Why?

Learning To Find Our Arteries & Veins

BLOOD PRESSURE

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Low Blood PressureOn the other hand, blood pressurebelow 100 mm Hg while the heart issqueezing, and below 60 mm Hgwhen it is relaxing is also not normal.But low blood pressure is not a dis-ease by itself unlike high blood pres-sure.

Whenever low blood pressure is de-tected, it is a sign of an underlyingillness that must be treated to raisethe blood pressure back to normal.Look for any cause that may havecaused bleeding : like accidents, frac-tures, piles, childbirth, etc. It may alsobe the effect of severe loss of water –dehydration – that may happen indiarrhoea or burns. People with lownutrition levels and with mental de-pression are also found to have bloodpressures below normal.

High Blood PressureIf the blood pressure is above 160 mm Hg while theheart is squeezing and above 95 mm Hg when resting(we measure it early morning for three days continously),then we call it as hypertension or high blood pres-sure.

The term Hypertension simply means more tension (orpressure) in the wall of the arteries. It has nothing todo with mental tension, though also, that can contrib-ute to high blood pressure! High B.P may be due tosome kidney diseases, but usually we cannot find anyother disease with it.

Treating High B.PPumping blood at pressures above 160/95 mm Hg resultsin the heart getting little rest and hence getting tired. Highblood pressure can cause heart disease and later heartfailure. It can also lead to some artery in the brain oranother part of the body to burst out and cause bleed-ing. Less salt in the diet and good exercise may preventone from taking medicines altogether.

Learn to Measure Blood PressureFind your friend’s blood pressure by using a blood pressuremachine.

Go Step By Step1 Get familiar with the parts of the BP machine like cuff,

tube, rubber bulb, valve etc. Also get familiar with thestethoscope, its earpieces, tube, diaphragm and bell.

2 Wrap the cuff of the blood pressure machine above yourfriend’s elbow, taking care that the rubber cuff coversthe front of the elbow.

3 Pump the rubber bulb after closing its valve while observing the meter (gauge). Keep pumping the bulb untilthe meter shows 200 mm Hg.

4 Keeping the diaphragm of the stethoscope on the frontof the elbow – a little towards the inner side – slowly start releasing the cuff by opening the valve of therubber 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 pressurewhen the heart is at rest. Write your friend’s blood pressure as X / Y mm Hg. Isn’t it simple?

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Know the Answers

The Heart & Blood Pipes

a. 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.

Mainly three common heart diseases need to be kept in mind. They are:1. Rheumatic Heart Disease (RHD)2. Heart Failure3. Heart Attack

HEART DISEASES

1. Rheumatic Heart Disease (RHD)RHD is a common heart problem in our place. Caused by bacteria, the disease spoils the valves ofthe 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 intothe chamber (II or IV).

Sore Throats Can DamageHeart Valves In Children

RHD is basically caused by bacteria that alsocause sore throat in children and youngadults. While the body tries to make antibod-ies against the germ, by mistake the anitibodiesattack the person’s own heart valves or herjoints.

This illness starts with what we call Rheumatic(Ryoo- ma-tik) Fever in which we have a

history of sore throat, joint swell-ing and high heart rate (pulse). Ifnot treated quickly with antibioticslike PENICILLIN,

COTRIMOXAZOLE OR DOXYCYCLINE,the illness may worsen and go on to damagethe heart valves. Highest possible doses of AS-PIRIN – as much as 3 to 6 tablets four times aday with food - are also allowed during the at-tack for Rheumatic Fever.

What Happens In RHD?Once the valves of the heart have been dam-aged, they may worsen with every new at-tack of the sore throat bacteria. If valves aredamaged, the blood is unable to be pumpedout of the heart and hence a backlog keepscollecting. This causes the heart to increasein size so that it has problems beating prop-erly.

The blood also gets stuck in veins of thelungs, so that water collects in the lungs andhence oxygen cannot be absorbed. If theheart disease is serious, RHD patients feelweak, have a bulged out chest on the leftside, may feel bad palpitations and get blue.As the heart has problems in beating, theymay be seen with swelling of legs and faceand ultimately die of heart failure.

Treating RHDThe RHD keeps worsening if the person gets sore throat repeatedly. It is advised that suchpatients should get Injection Penicillin every month from a doctor, or takeCOTRIMOXAZOLE daily until five years of the last attack OR till the person becomes20 years of age, whichever is later. It is rare to see the germ troubling people beyond thisage, 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 avoidfurther strain on the heart. Any load of pregnancy, an operation or even something simplelike getting a tooth removed can put the life of a RHD patient in danger. Persons’ withRHD should avoid getting pregnant and inform the surgeon/doctor about RHD beforeoperation 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.

heart valves

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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 halfan hour

· pain spreading to the left arm or neck· feeling of “ end of this world,”· cold sweat on the forehead.

Why Heart Attacks Happen?It is mainly because of a clot blocking one or more of the threearteries supplying blood to the heart. Until the blood supplycan be arranged from the other arteries, some parts of heartmuscle get no oxygen and pain a lot.

If a large part of the heart muscle is affected, the heart maynot be able to pump sufficient amount of blood. In such cases,the heart fails and the person may even die.

Who Gets Heart Attacks ?People who get heart attacks are usually be-yond 45 years of age, but not always. Manywould have been on treatment for high B.P.or for heart disease due to repeated pain inthe heart (that lasts for a few minute at a timeand worsens with exertion). Yet, in many theillness is a first ‘attack’ on the heart.

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3. Heart FailureThe heart may fail if there is too much of pressure in the arteries to pumpacross – as in high B.P. - or if there is too much to pump that the heartmuscles 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 heartmuscle that it cannot pump effectively.

Heart failure of the Left side of the heart causesbreathlessness (that may worsen to such a levelthat it is not possible to lie down also), pain in thechest and dry cough with a wheeze. If severe, bloodmay be thrown out with cough.

Heart Failure of the Right side may causeswelling of the legs and face. The liver alsoenlarges to press on the stomach, and thepatient feels heavy in the stomach.

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

What To Do In Heart Attacks ?Refer to a hospital immediately any such patient that you suspect has suffereda HEART ATTACK ! But give an ASPIRIN tablet with something to eatbefore you send her. It can make the difference between living and dying asASPIRIN decreases the ability of blood to clot.

Know the Answers21-11

The Heart & Heart Diseases

a. 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 ____________________.

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