Cardiovascular system Layers of heart ECG of heart

2. INTRODUCTION

3. The heart is roughly cone shaped
hollow muscular structure.
It is 10cm long, 9cm wide, 6cm
thickness.
Weight 250-300g.
The heart is situated in the thoracic
cavity between lungs and above
diaphragm.
It is lies obliquely, a little more to the
left than the right side.

4. PERICARIDUM/
EPICARDIUM(OUTER
LAYER)
MYOCADIUM
( MIDDLE LAYER)
ENDOCARDIUM
(INNER LAYER)

5. PERICARIDUM EPICARDIUM(OUTER LAYER)
Also called outer covering layer.
Double layer or sac
Attach outer layer to the diaphragm and sternum.
Maintain the position of heart.
MYOCADIUM ( MIDDLE LAYER)
 Thick middle layer of the heart.
Form bulk of the heart.
Responsible for the pumping action of the heart.
Act as contractile unit, pacemaker, conductive system.
ENDOCARDIUM (INNER LAYER)
It is innermost lining of the heart.
It is lining the cavities, valves of the heart

6. TWO SUPERIOR CHAMBER
RIGHT ATRIUM
RIGHT VENTRICLES
TWO INFERIOR CHAMBER
LEFT ATRIUM
LEFT VENTRICLES

7. There are three types of blood vessels:-
1. Arteries: they carry blood away from your heart.
2. Arterioles: medium sized arteries then divided int small arteries which
in turn divide into still smaller arteries as arterioles.
3. Veins: They carry blood back toward your heart.
4. Venules: the group of capillaries within a tissue reunite to form small
veins called as venules.
5. Capillaries: The smallest blood vessels, connect arteries and veins.

8. Atrioventricular valve
Tricuspid valve( 3 cups/flaps)
Bicuspid valves( 2 cups/flaps)
Semilunar valves
Pulmonary valves
Aortic valve

9. 1. Pumping oxygenated blood to the other body parts.
2. Pumping hormones and vital substances to different parts of the body.
3. Carrying metabolic waste products from the body.
4. Maintain blood pressure.
5. There are approximately 40,000 cells present in the heart known
as sensory neurits which play a vital role in memory transfer.

10. DIFFERENT BETWEEN ARTERIES AND VEINS

11. STRUCTURE OF HEART

13. STEPS INVOLVED IN BLOOD flow IN HEART
First of all know that,
1. The right chamber of the heart carries de-oxygenated blood ( oxygen-
poor) blood.
2. The left chamber carries oxygenated blood( oxygen rich)blood.
3. The superior vena cava responsible to carry deoxyenated blood from the
upper part of the body.
4. The inferior vena cava responsible to carry deoxyenated blood from the
lower part of the body.
5. Coronary sinus delivers deoxygenated blood from the heart muscles
directly into right atrium.
6. All the collected deoxygenated blood from right atrium to right ventricles go
through tricuspid valve ( right atrioventricular valve)

14. 7. When the blood goes to the right ventricles closed tricuspid valve for the
prevention of backflow of the blood.
8. After this , pulmonary valve going to the open and then blood goes o pulmonary
arteries.
( Here 2 arteries are presents in heart. 1. is present on the right side that
called right pulmonary artery and it is responsible for the transfer blood to
the right lung, 1. is present on the left side that called left pulmonary artery
and it is responsible for the transfer blood to the left lung)
9.The blood is collected into the lungs and here deoxygenated blood convert into
oxygenated.
10.The oxygenated blood from right and left lung is collected by four pulmonary
veins and poured into left atrium.
11.After this the bicuspid valve get open and blood goes to the left ventricles and
bicuspid valve get closed to prevent back flow of blood.

15. 12. After this blood goes to aortic valve and aorta
13.Through aorta blood get pumped to the different organ of the body.
Circulation of blood
1. Systemic circulation
2. Pulmonary circulation
3. Coronary circulation
4. Portal circulation
Systemic circulation
A. Circulation of blood supply to all parts except lungs.
B. Circulation start from aorta

16. C. Then goes to arteries, capillaries, venules.
D. This venules are joint with superior vena cava, inferior vena cava.
E. This 2. trunks SVC and IVC open in right atrium.
PULMONARY CIRCULATION
A. Involve purification of blood in lungs.
B. Right ventricles pump deoxygenated blood.
C. Then goes to the lungs and get purified.
D. Then blood goes to the right and left pulmonary veins.
E. This veins are open in the left atrium.
Coronary circulation
A. In this circulation blood supply heart itself.
B. The right and left coronary arteries arise from ascending aorta.

17. C. They supply blood to heart.
D. Then blood goes to the coronary sinus.
E. Coronary sinus open in right atrium.
Portal circulation
Circulation of blood through liver,
A. Portal vein carries blood to liver ( circulate blood in stomach, intestine,
pancreas)
B. The portal vein divides into capillaries.
C. Capillaries joint to hepatic artery.
D. The venous blood of liver is collected by hepatic vein.
E. Venuoles joint with inferior vena cava.

18. CONDUCTING SYSTEM OF HEART
A special system of the heart is responsible for the rhythmic contraction and
relaxation which leads conduction of impulses in the heart.
This system can be divided into five parts,
SA nodes or sinoatrial node
AV node or Atrioventricular node
AV bundle or bundle of his
Right and left bundle branches.
Conduction myofibrils.
SA nodes or sinoatrial node
1. Also called natural pacemaker of heart.
2. They produce electrical impulses(100tmes/min)
3. Located at walls of right atrium below the enterance of SVC
4. It initiate the contraction of cardiac muscle producing heart beat

20. AV node or Atrioventricular node
1. It is second pacemaker
2. Located at the lower side of intratrial septum
3. It is consist intrnodal fibre. These fibres conduct impulses from SA to AV node.
4. It is having width- 10mm, long- 22mm, thick- 3mm.
 AV bundle or bundle of his
1. It is also called as A.V bundles.
2. Receive impulse from AV node and transmit to purkinji fibrer.
3. It is locates septum of heart.
 Right and left bundle branches
1. After traveling along the AV bundle, the action potential then enters both the
right and left bundle branches that runs through the interventricular septum
towards the apex of the heart.
 Conduction myofibrils/ purkinji fibres
1. It is conduct the impulse from the apex of the heart to reminded the ventricular
myocardium.

21. Cardiac cycle
The event occurring in the heart from the beginning of one heart beat to
the beginning of other heart beat is called as the cardiac cycle.
In normal cardiac cycle, the two atria contract while two ventricles relax.
Then, the two ventricles contract and the two atria undergo relaxation.
A single cardiac cycle includes all the events associated with one heartbeat/min
72-75/day
A cardiac cycle lasts 0.8 sec.
A cardiac cycle occurs in two phases, systole and diastole of the atria plus
systole and diastole of the ventricles.
The cardiac cycle is divided into three phases:-
1. Phases of ventricular filling.
2. Phase of relaxation.
3. Phases of ventricular contraction.

23. Heart sound
The sound of the heart beat comes primarily from blood turbulence
caused by the closing of the heart values.
There are four heart sounds but in a normal heart only the first and second
heart sounds (S1 and S2) are loud enough to be heard through a stethoscope.
 The timing of heart sounds relative to other event in the cardiac cycle.
 The first sound (S1) which can be described as a Lubb sound is louder and a
bit longer than second sound.
 S1 is caused by blood turbulence associated with closure of the AV values
soon after ventricular systole begins.
 The second sound (S2) which is shorter and not as loud as the first sound can
be described as a Dupp sound.

24. CARDIACOUTPUT
It is the volume of blood ejected from the left ventricles into the aorta each minute.
Cardiac output(CO) equals the stroke volume(SV) : - The volume of blood
ejected by the ventricles during each contraction.
multiplied by Heart rate(HR):- The number of heart beat per minute.
CO(ml/min)= SV(ml/beat) X HR(beat/min)
The average CO is,
CO= 70ml/beat X 75beats/min
5250ml/min
5.25l/min

25. BASICS OF ECG
THE WORD electrocardiogram is derived from Greek word,
Electro- Electrical activity.
Kardia- Heart.
Graph- Write.
The pattern of electrical activity can be displayed on oscilloscope screen or
printed out on paper. This tracing called an electrocardiogram.
The instrument used to record the change is called as an electrocardiograph.
When muscle contract, there is in the electral potential across the member be of
muscle fibers.
It consist of three waves,
P wave.
QRS wave.
T wave.

26. The detection is done by connecting lead
on the surface of body.
Lead I- right arm and left arm
Lead II- right arm and left leg
Lead III- Left arm and left leg
The recording is design by letters
P,Q,R,S and T.
 Wave P- Caused by contraction of
atria.
 Wave QRS -Caused by contraction
of ventricles.
 Wave T- Produced by relaxation of
ventricles.

27. FACTOR AFFECTING HEART RATE
1. AUTONOMIC NERVOUS SYSTEM
2. CIRCULATING NEUROHORMONES
3. EXERCISE
4. EMOTIONAL STATES
5. GENDER
6. AGE
7. TEMPERATURE
8. BARORECEPTOR REFLEX

28. BLOOD PRESSURE
Blood pressure is lateral pressure exerted by blood on the vessels walls while
flowing through it.
 systolic BP- it refers to phase of ventricular contraction.
Diastolic BP- it refers to phase of ventricular relaxation.
Normal BP =120/80mm Hg.
The various methods for determination of blood pressure are as follows;
1. Oscillatory method.
2. Palpatory method.
3. Auscultatory method.

29. BLOOD PRESSURE REGULATION
A. Short term control of BP.
1. Baroreceptor reflex.
2. Chemoreceptor reflex.
3. CNS schemic response.
B. Intermediate term
1. Capillary fluid shift.
2. Stress relaxation.
C. Long term
1. Renal body fluid mechanism.
2. Rennin angiotensin system.

30. Disorders of cardiovascular system
Coronary artery disease(CAD)
In this condition plaque is accumulated in coronary arteries, which leads to the
reduction in blood flow in heart.
Myocardial infarction/ schemia
Partial obstruction of blood flow in coronary arteries and reduce the blood flow
in myocardium. Ischemia causes the reduction of oxygen supply and weaken
the cells without killing them.
Angina pectoris
Angina isn’t a disease. It’s a symptom and a warning sign of heart
disease.angina is chest pain due to lack of oxygen supply to the myocarium.
Arrhythmia
The arrhythmia is abnormal rhythm as result of a defect in the conduction system
of he heart.

31. Bradycardia
It refers to a slow heart rate( below 50 beats per min)
Tachycardia
It refers to a fast heart rate( over 100 beats per min)
Fibrillation
It refers to rapid , uncoordinated heart beat.
Hypotension
Decreased blood pressure below110/60mm hg
Hypertension
Increased blood pressure above 120/80mm hg