The work of the human heart реферат

Обновлено: 02.07.2024

WORK OF THE HUMAN HEART. The human heart contract from the first moment of life till the last. Reduction of the heart pumps blood through the arteries to all parts of the body. Physiology found that adult heartbeat ranges from 60 to 72 beats per minute. Children have a much higher rate of heartbeats. Research has found that the rate of heart rhythm increases depending on different emotions. Each heart beat is accompanied by a rest period. Each contraction and relaxation period of cardiac cycle. Each cardiac cycle consists of three phases: the first phase short cuts atrial systole, the second phase of a longer-term reduction in ventricular Systole. The rest period is called diastole. Research many physiologists evaluated the role of the ventricles as main pump of the human heart.

РАБОТА человеческого сердца. Человеческого сердца контракт с первого момента жизни до последнего. Сокращение сердца качает кровь через артерии ко всем частям тела. Физиология обнаружили, что диапазоны взрослых пульса от 60 до 72 ударов в минуту. Дети имеют гораздо более высокую скорость сердечных сокращений. Исследования показали, что скорость сердечного ритма увеличивается в зависимости от различных эмоций. Каждое биение сердца сопровождается периодом отдыха. Каждое сокращение и расслабление период сердечного цикла. Каждый сердечный цикл состоит из трех фаз: первая фаза коротких стрижек систолы предсердия, второй этап сокращения долгосрочного в желудочковой систолы. Период покоя называется диастолы. Исследования многие физиологи оценили роль желудочков как основного насоса человеческого сердца.

работу человеческого сердца.сердце человека, контракт с первых минут жизни до последнего.сокращение сердце перекачивает кровь через артерии всех частей тела.выяснилось, что взрослые сердца физиологии составляет от 60 до 72 удара в минуту.дети имеют гораздо более высокие темпы сердцебиения.исследования показали, что уровень сердечный ритм увеличивается в зависимости от различных эмоций.каждое сердце бьется, сопровождается период отдыха.каждое сокращение и ослабление период сердечный цикл.друг сердечный цикл состоит из трех этапов: первый этап сокращениям фибрилляция систола, второй этап долгосрочного сокращение желудочков систола.остальной период называется диастола.исследования многих физиологов оценку роли желудочков в качестве основного насоса сердца человека.

human heart is about the size of a fist and weighs about 250-350 gm (9 oz).

Blood supplies food and oxygen to the cells of the body for their life needs and removes the waste

products of their chemical processes. It also helps to maintain a consistent body temperature, circulate

hormones, and fight infections. The brain cells are very dependent on a constant supply of oxygen. If the

circulation to the brain is stopped, death ensues shortly. Since heart attacks are the number-one cause

of death in the United States, the heart gets a great deal of attention.

The role of the heart was long considered a mystery and often given elevated importance. Some thought it

was the seat of the soul. Others thought it was the center of love, courage, joy, and sadness. Primitive

man must have been aware of the heartbeat and probably recognized the heart as an organ whose malfunction

could cause sudden death.

The Hippocratic De Corde, which probably dates from the time of ARISTOTLE, describes the construction of

the heart’s valves. LEONARDO DA VINCI made exquisite drawings of the heart, but it was not until the

publication of William HARVEY’s De Motu Cordis (1628) that the heart’s specific role in relation to

circulation was widely understood.

STRUCTURE AND FUNCTION OF THE HUMAN HEART

The heart’s wall has three parts. Muscle tissue, or myocardium, is the middle layer. The inner layer, or

endocardium, that lines the inside of the heart muscle consists of a thin layer of endothelial tissue

overlying a thin layer of vascularized connective tissue. The outside of the heart, the epicardium, is in

intimate contact with the pericardium; this serous membrane is a closed sac covering the heart muscle’s

outside wall. Within the sac, a small amount of fluid reduces the friction between the two layers of

tissue. In addition to muscular and connective tissue, the heart muscle contains varying amounts of fatty

tissue, especially on the outside. Both anatomically and functionally, the heart is divided into a left

and a right half by the cardiac septum. Each half contains two separate spaces: the atrium (pl. atria),

or auricle, and the ventricle. The upper reservoirs, or collecting chambers, are the thin-walled atria,

and the lower pumping chambers are the thick-walled ven!

tricles. The total thickness of the ventricular walls is about three times that of the atria; the wall of

the heart’s left half is approximately twice as thick as that of the right half. The thickness of the

heart muscle varies from 2 to about 20 mm (0.1 to 0.8 in). This thickness is correlated with the maximum

pressure that can be attained in each chamber.

FLOW OF BLOOD THROUGH THE HEART

The right atrium receives oxygen-poor blood from two major veins: the superior and inferior vena cava,

which enter the atrium through separate openings. From the right atrium the blood passes through the

tricuspid valve, which consists of three flaps, or cusps, of tissue. This valve directs blood flow from

the right atrium to the right ventricle. The tricuspid valve remains open during diastole, or ventricular

filling; however, when the ventricle contracts, the valve closes, sealing the opening and preventing

backflow into the right atrium. Five cords attached to small muscles (papillary muscles) on the

ventricles’ inner surface prevent the valves’ flaps from being pushed backward. From the right ventricle

blood is pumped through the pulmonary, or semilunar, valve, which has three half-moon-shaped flaps, into

the pulmonary artery. This valve prevents backflow from the artery into the right ventricle. From the

pulmonary artery, blood is pumped to the lungs, where it gives up ca!

rbon dioxide and receives oxygen, and then is returned to the heart’s left side through four pulmonary

veins (two from each lung) to the left atrium and then through the mitral valve, a two-flapped valve also

called a bicuspid valve, to the left ventricle. As the ventricles contract, the mitral valve prevents

backflow of blood into the left atrium, and blood is driven through the aortic valve into the AORTA, the

major artery, which supplies blood to the entire body. The pulmonary valve, like the aortic valve, has a

semilunar shape and a unidirectional function.

The blood supply to the heart muscle is furnished mainly by the CORONARY ARTERIES, which originate from

the aorta immediately after the aortic valve. These vessels pass through the fatty tissue beneath the

pericardium and then branch out into the heart muscle.

The coronary veins transport the deoxygenated blood from the heart muscle to the right atrium. The

heart’s energy supply is almost completely dependent on these coronary vessels. Only the tissues lying

directly beneath the endocardium receive a sufficient amount of oxygen from the blood within the cavities

REGULATION OF THE HEARTBEAT

The heart muscle pumps the blood through the body by means of rhythmical contractions (systole) and

dilations (diastole). The heart’s left and right halves work almost synchronously. When the ventricles

contract (systole), the valves between the atria and the ventricles close, as the result of increasing

pressure, and the valves to the pulmonary artery and the aorta open.

When the ventricles become flaccid during diastole and the pressure decreases, the reverse process takes

place: through the valves between the atria and the ventricles, which are now open again, blood is drawn

from the atria into the ventricles, and the valves to the pulmonary artery and the aorta close.

At the end of diastole the atria also contract and thus help to fill the ventricles. This is followed by

systole. The electrical stimulus that leads to contraction of the heart muscle originates in the heart

itself, that is, in the sinoatrial node (SA node), or pacemaker. This node, which lies just in front of

the opening of the superior vena cava, measures no more than a few millimeters. It consists of heart

cells that emit regular impulses. Because of this spontaneous discharge of the sinus node, the heart

muscle is automated, and a completely isolated heart can contract on its own, as long as its metabolic

processes remain intact. The electrical stimulus from the SA node becomes propagated regularly over the

muscle cells of both atria and reaches the atrioventricular node (AV node), which lies on the border

between the atria and the ventricles. The stimulus continues into the bundle of His. This bundle proceeds

for about a centimeter and then divides into a left and a right!

bundle branch. The two bundle branches lie along the two sides of the heart’s septum and then proceed

toward the apex. The small side branches that come off are the Purkinje fibers, which conduct the

stimulus to the muscle cells of the heart’s ventricles.

The Purkinje fibers differ from the cardiac muscle cells and conduct the stimuli more rapidly. However,

the AV node conducts the stimulus relatively slowly. As a result, the heart chambers contract regularly

and evenly during systole, and ventricular contraction does not coincide with that of the atria; so the

pumping function is well-coordinated. Potentially, the whole conduction system is able to discharge

spontaneously and can take over the function of the SA node. The rate at which the cells of the SA node

discharge under normal circumstances is externally influenced through the autonomic nervous system, which

sends nerve branches to the heart. Through their stimulatory and inhibitory influences they determine the

resultant heart rate. In adults at rest this is between 60 and 74 beats a minute. In infants and young

children it may be between 100 and 120 beats a minute. Tension, exertion, or fever may cause the rate of

a healthy heart to vary between 55 and 200 beats a minu!

The output of the heart is expressed as the amount of blood pumped out of the heart each minute: the

heart minute-volume (HMV). This is the product of the heart rate and the stroke volume (SV), the amount

of blood pumped out of the heart at each contraction.

EVOLUTION OF THE HEART

The hearts of primitive vertebrates apparently had only one atrium and one ventricle. Since their body

temperature and metabolic rate fluctuated with the environmental temperature, they did not need as

efficient a circulatory system as mammals and birds. The two-chamber heart is retained by modern fish,

but oxygen-rich blood does not mix with oxygen-poor blood, because the blood is aerated at the gills and

goes directly into systemic circulation, not to the heart. As the primitive lung evolved in amphibians,

two circulatory systems arose. The problem of mixing oxygenated and deoxygenated blood was resolved in a

number of amphibians such as the FROG, in which the single atrium is divided into two separate chambers.

Thus there is only a slight mixing of the bloods in these three-chambered hearts. This adaptation appears

to help the frog when it is under water, since the skin provides oxygen when the lungs cannot be used. In

SIRENS a partial division takes place in the ventricle !

As animals became larger and more active on land, they needed more pressure to provide faster flow. The

sides of the heart were separated when a septum formed to divide the ventricle into two chambers. Birds

and mammals have completely separate chambers and have more blood per tissue weight and more pressure,

because the tissues of birds and mammals (warm-blooded vertebrates) require a constant perfusion of

oxygen-rich blood in order to maintain their high metabolic rates and constant body temperature.

The closure of the heart valves and the contraction of the heart muscle produce sounds that can be heard

through the thoracic wall by the unaided ear, although they can be amplified by means of a STETHOSCOPE.

The sounds of the heart may be represented as lubb-dupp-pause-lubb-dupp-pause. The lubb sound indicates

the closing of the valves between the atria and ventricles and the contracting ventricles; the dupp sound

indicates the closing of the semilunar valves. In addition, there may also be cardiac murmurs, especially

when the valves are abnormal. Some heart murmurs, however, may also occur in healthy persons, mainly

during rapid or pronounced cardiac action. The study of heart sounds and murmurs furnishes valuable

information regarding the condition of the heart muscle and valves. The heart sounds are recorded with

the aid of sensitive microphones (phonocardiography), so that anomalies of the heart or the valves can be

analyzed. The conduction of the contraction stimulus can!

also be recorded on the body surface by an ELECTROCARDIOGRAPH. This measures the differences in

potential (in microvolts) that exist between a number of fixed points on the limbs and the chest wall.

The electrocardiogram (cardiogram, ECG) that is obtained in this way furnishes information about the

rhythm of the heart, the conduction of the stimulus, and the condition of the heart muscle. Other methods

that have been devised to examine the heart are the mechanical recording of the heartbeat,

echocendiography and radioisotopes, X-ray analysis of the heart’s form and movements, and X-ray contrast

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. Physiologists have determined that in the adult the heart makes from 60 to 72 beats per minute. In children the rate of the heart beat is much higher. Research work has determined that rate of heart beat increases depending on different emotions. You can help it work long and well. You can strengthen 5 it, protect it from disease 6 by exercises and regular 7 regimen'.

Take your pulse and in such а way you can control the work of your heart.

After heavy exercises the heart works faster and then the pulse will be faster too, perhaps 100 (one hundred) beats. After a minute or two the pulse will be normal again.

Each beat of the heart is followed by a period of rest. Each contraction and a period of rest compose a cardiac cycle.Each cardiac cycle consists of three phases: the first phase of short contraction — the atrial systole, the second phase ofa more prolonged contraction — the ventricular systole. The period of rest is called the diastole.

Research work of many physiologists has estimated the role of the ventricles as the main pump of the human heart

Heart disorders fall into two broad groups: congenital and acquired. Congenital heart defects are caused by structural defects. Acquired heart disease is mainly due to rheumatic fever.

Congenital defects may result in cyanosis if the defect is such that blood does not pass through the lungs for oxygen-ation. The patient has blue lips and blue-finger and toe-nails. The ends of the fingers and toes are rounded and club-like. Sometimes there is an opening between the left and right side of the heart, or even between the aorta and pulmonary ' artery. Symptoms depend on the type of heart disease. Sometimes, the defect is picked up on a routine examination; at other times there may by breathlessness, difficulty in walking or running, swelling of feet and puffiness efface, and later of the whole body. Some these anomalies can be surgically corrected.

Proverb: A merry' heart does good 1 like 3 a medicine 4 .

Believe It or Not Different Hearts

The lion (лев) has the smallest heart of all wild animals (диких животных).

King Philip the Second of Spain (Филипп 11, король Испании) was a

coward (трус) but he had the largest heart of any known (известный) man

Exercises.

Give Russian equivalents:

a) 1. The human heart makes 60—80 contractions perminute.

2. On physical exertion the heart has a short period of restand the diastole becomes less.

3. Ten tons of blood are pumped through the heart daily.

4. The heart acts as a pump.

5. John Floyer, an English doctor, was the first scientist to find out the varying pulse rate in men.

b) 1) pump [рлтр] п насос, v накачивать, нагнетать, выталкивать, выбрасывать

2) rate [reit] п частота, степень pulse rate — частота пульса respiratory rate — частота дыхания

3) beat [bi:t] п удар; v ударять (beat, beaten)

4) per minute — в минуту

5) contract [kan'traekt] сокращаться

6) artery ['a:t9n] n артерия

7) systole ['sisteh] n систола

8) diastole [dai'estah] и диастола

9) atrium [eitriam] n (pi. atria) предсердие

10) ventricle ['ventrikl] n желудочек

1.1 disorder [dis'3:d9] расстройство, нездоровье

12 congenital [kan^emll] врожденный

13. acquired [a'kwaiad] приобретенный

14. club-like [klub] зд. похожие на барабанные палочки

15. pulmonary [рл1тэпэп] а легочный

16. to depend on [di'pend] v зависеть от

17. to pick up [pik] уловить, обнаружить

18. puffinss ['pAfmes] одутловатость

П Answer the questions:

1. How can you strengthen your heart?

2. Can you take anybody's pulse?

3. What do you learn when you take the pulse?

4. How many beats is the pulse of a healthy person?

5. When does the heart work faster?

6. Where do arteries cany blood?

7. Where do veins cany blood? .

8. What kind of groups do the heart disorders fall?

9. What are 1the symptoms of some congenital heart defects?

10. Can these anomalies be surgically corrected?

3. Translate into English

человеческое сердце, сокращаться, сокращения сердца, артерия, взрослый человек, 72 удара в минуту, определить частоту сердцебиения, зависит от различных эмоций, сердечный цикл, систола предсердия, систола желудочка, диастола, насос.

укрепить сердце; защитить сердце; это легко и полезно; щупать пульс;

таким образом; контролировать работу сердца; 70 ударов в минуту; пульс будет учащенным; пульс будет нормальным; измерить давление; прослушать сердце;

врожденный, приобретенный, дефекты (пороки) сердца, структурные дефекты, врожденные пороки сердца, у больного посиневшие губы, пальцы на руках и ногах — закругленные, похожи на барабанные палочки, отверстие, легочная артерия.

2)Задание на дом: Используя изученный материал , составьте рассказ “Work of the human heart. Heart Disease

Методическая разработка семинарско-практического занятия

(для учащихся)

ЗАНЯТИЕ №:7-2 часа

Тема: “ Pneumonia”

1. Мотивация цели: основанием для овладения данной темы является использование иностранного языка как средства получения новой информации , связанной с медицинской тематикой , актуализация межпредметных связей, овладение соответствующим языковым материалом для обсуждения актуальных событий в медицине, а также перспектива использования приобретенных навыков и умений в профессиональных целях ( умение говорить с коллегой, читать для расширения кругозора, писать иностранному коллеге)

2. Цель самоподготовки: после самостоятельного изучения темы

СТУДЕНТ ДОЛЖЕН ЗНАТЬ :

-лексико-фразеологический минимум по теме;

-изученную грамматическую конструкцию;

-границы применимости терминов и частоту их использования в медицинской литературе и практической деятельности.

СТУДЕНТ ДОЛЖЕН УМЕТЬ:

-участвовать в беседе на темы повседневной жизни ;знать речевой этикет;

-переводить тексты соответствующей тематики, при необходимости используя словарь;

-выражать свои мысли в устной форме по пройденной тематике с использованием активно усвоенных грамматических правил;

- пользоватьсятехническими словарями и другими справочными материалами , понимать невербальные средства кодирования информации – схемы, диаграммы, и т. д. грамотно писать термины ,относящиеся к лексико-фразеологическому минимуму ;

-воспринимать на слух тексты по пройденной теме ( с10-15 %незнакомой лексики)

Исходный уровень знаний

Для усвоения материала данной темы студент должен использовать знания по темам:

Темы , изученные на занятиях по клиническим дисциплинам.

4.План изучения занятия

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. Physiologists have determined that in the adult the heart makes from 60 to 72 beats per minute. In children the rate of heart beat is much higher. Research work has determined that rate of heart beat increases depending on different emotions.

Each beat of the heart is followed by a period of rest. Each contraction and a period of rest compose a cardiac cycle.

Each cardiac cycle consists of three phases: the first phase of short contraction - the atrial systole, the second phase of a more prolonged contraction - the ventricular systole. The period of rest is called the diastole.

Research work of many physiologists has estimated the role of the ventricles as the main pump of the human heart.

насос, накачивать, нагнетать, выталкивать, выбрасывать

beat (beat, beaten)

atrium (pi. atria)

Answer the questions to the text:

1. How many beats makes a heart of an adult?

2. Does the heart act as a pump?

3. Is the rate of heart beat much higher in children?

4. Is each beat of the heart followed by a period of rest?

5. How many phases has each cardiac cycle? Whatarethey?

Работа человеческого сердца

Человеческое сердце сокращается с первого момента жизни до последнего.Сокращений сердца качают кровьчерез артерии ко всем частям тела. Физиологи установили, что у взрослого человека сердце сокращается от 60 до 72 ударов в минуту. У детей скорость сердцебиения намного выше. Научно-исследовательская работа установила, что скорость сердцебиения увеличивается в зависимости от различных эмоций.

За каждым сокращением сердца следует период покоя. Каждое сокращение и каждый период отдыха составляют сердечный цикл.

Каждый сердечный цикл состоит из трех фаз: первая фаза короткого сокращение - систола предсердий, второй фаза более длительного сокращения - систолы желудочков.Период покоя называется диастола.

Научно-исследовательская работа многих физиологов оценила роль желудочков в качестве главного насоса человеческого сердца.

Ответьте на вопросы к тексту:

1. Сколько ударов делает сердце взрослого?

2. Действует ли сердце как насос?

3. Является ли скорость сердцебиения намного выше у детей?

4. За каждым ударом сердца следует период покоя?

5. Сколько фаз имеет каждый сердечный цикл? Какиеони?

The patients need your help

The whole life of a nurse is devoted to people. She is responsible for her patient. Every nurse must have enough knowledge of her work. She must help her patients at any hour of the day or night. That's why you should know how to help a person in different situations.

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