In this presentation there is the complete basic anatomy of the Heart. in this presentation there is complete description of heart including anatomy, external feature, relations of the heart, layers of heart, structure and functions of heart, circulation of heart, blood supply and nerve supply of the heart is explained in the simplest form which is very useful for the students who are appearing for the various medical entrance exams like medical, dental, physiotherapy, ayurved, pharmacy, nursing and also beneficial for the students who are doing preparation for NEET and other medical entrance

1. Anatomy Of The Heart
SAURABH PURI

2. Objectives
 Anatomy of the Heart
 External feature of heart
 Functions
 Circulation of blood
 Blood supply and Nerve supply

3. Heart
 The heart is a conical hollow muscular organ
situated in the middle mediastinum(middle
space left in the thoracic cavity in between the
lungs).
 It is enclosed within the Pericardium.
 It pumps blood to various parts of the body to
meet their nutritive requirements.
 The direction of blood flow, from atria to the
ventricles is downwards forwards and to the
left.
 The heart measures about 12 × 9 cm and
weighs about 300g in males and 250g in
females.

4. External features
The heart has :
 An apex
 A base
 Three surfaces – anterior, inferior, lateral
 Borders : upper, inferior, right and left
borders are present.

5. Relations of heart
 Superiorly – the aorta, superior vena
cava, pulmonary artery and pulmonary
vein.
 Inferiorly – the diaphragm
 Anteriorly – the ribs and and intercostal
muscles.
 Posteriorly – the esophagus, trachea, left
and right bronchus, descending aorta,
inferior vena cava and thoracic vertebrae
 Laterally – the lungs

6. Structure and function
The heart is subdivided by septa into right and left halves, and a
constriction subdivides each half of the organ into two cavities, the
upper cavity being called the atrium, the lower the ventricle. The
therefore, consists of four chambers:
 right atrium
 left atrium
 right ventricle
 left ventricle

7. The Heart Chambers
 Atria
Small thin walled chambers, receive blood from right side through
superior vena cava and from left side through pulmonary veins
 Ventricle
Ventricles make up the most of the mass of the heart. The heart has
two ventricles which are its lower chambers. These ventricles pump
blood from the heart to the body.

8. Layers of heart wall
The wall of the heart consist of
three layers
- The epicardium (external layer)
- The myocardium (middle layer)
- The endocardium (inner layer)

9.  The epicardium is the outermost layer of heart, it is actually the visceral
layer of the serous Pericardium. It protects and lubricate the heart.
 The myocardium is the middle thickest layer of the heart contains the
muscle fibres which are responsible for pumping.
 The endocardium lines inner surface of the heart chambers and valves
comprised of a layer of endothelial cells, and a layer of subendocardial
connective tissue.

10. Valves
The heart has four valves. All four valves of the heart have a singular purpose:
allowing forward flow of blood but preventing backward flow.
Atrioventricular valves between the atria and ventricles
 tricuspid valve (R side of the heart)
 mitral valve/bicuspid valve (left side of the heart)
Semilunar valves which are located in the outflow tracts of the ventricles
 aortic valve (Left side heart)
 pulmonary valve (Right side heart)

11. Valves of the Heart

12. Circulation of blood
It is best to remember the four chambers and four valves in order of the
series that blood travels through the heart:
 Venous blood returning from the body drains into the right atrium via
the SVC, IVC and coronary sinus
 The right atrium pumps blood through the tricuspid valve into the right
ventricle
 The right ventricle pumps blood through the pulmonary semilunar valve
into the pulmonary trunk to be oxygenated in the lungs

13.  The right ventricle pumps blood through the pulmonary semilunar valve
into the pulmonary trunk to be oxygenated in the lungs
 Blood returning from the lungs drains into the left atrium via the four
pulmonary veins
 The left atrium pumps blood through the bicuspid (mitral) valve into the
left ventricle
 The left ventricle pumps blood through the aortic semilunar valve into the
ascending aorta to supply the body.

14. Pathway of blood flow

15. Blood supply
The heart is supplied by two coronary arteries:
(1). Left main coronary artery carries 80% of the flow to the heart muscle. It
is a short artery that divides into two branches
 Left anterior descending artery that supplies anterior two-thirds of the
inter-ventricular septum and adjoining part of the left ventricular anterior
wall
 Circumflex coronary artery that supplies blood to the lateral and posterior
portions of the left ventricle.

16. (2). Right coronary artery: branches supply the right ventricle, right atrium, and
left ventricle's inferior wall.
 The right coronary artery divides into smaller branches, including the right
posterior descending artery and the acute marginal artery. Together with the
left anterior descending artery, the right coronary artery helps supply blood to
the middle or septum of the heart.
 Smaller branches of the coronary arteries include: obtuse marginal (OM),
septal perforator (SP), and diagonals.

17. Coronary arteries

18. Nerve supply
 The nervous supply to the heart is autonomic, consisting of both
sympathetic and parasympathetic parts.
 The sympathetic fibres arise from the pressor centre in the upper part of
the medulla oblongata.
 The parasympathetic fibres arise from the depressor centre in the lower
part of the medulla oblongata.

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