It's about heart

1. Anatomy of
heart

2. Introduction
The heart is a muscular organ that serves to
collect deoxygenated blood from all parts of the
body, carries it to the lungs to be oxygenated and
release carbon dioxide. Then, it transports the
oxygenated blood from the lungs and distributes it
to all the body parts.

3.  The heart pumps around 7,200 litres of blood in a day throughout the
body.
 The heart is situated at the centre of the chest and points slightly
towards the left.
 On average, the heart beats about 100,000 times a day, i.e., around 3
billion beats in a lifetime.
 An adult heart beats about 60 to 100 per minute.
 Newborn babies heart beats faster than an adult which is about 70 to
180 beats per minute.

4. Anatomy
The heart is a conical hollow muscular
organ situated in the middle mediastinum
and is enclosed within the pericardium
The heart measures 12 x 8.5 x 6 cm
weighs ~310 g (males) and ~255 g
(females)
The Greek name for the heart is cardia from
which we have the adjective cardia

5. Relations Anteriorly: the body of the sternum, and
adjoining costal cartilages; left lung, and
pleura
Posteriorly: esophagus, descending thoracic
aorta, azygos, hemiazygos veins, and thoracic
duct
Superficially : bifurcation of the main
pulmonary trunk
Inferiorly: diaphragm
Laterally: lungs, pleura

6. Coverings of the Heart Walls
Pericardium: The heart is enclosed in a double-walled sac called the pericardium.
It consists of two main parts:
The fibrous pericardium - The fibrous pericardium is composed of tough, inelastic, dense
irregular connective tissue.
o Prevent overstretching of the heart
o Protection of heart
o Anchors the heart in the mediastinum
The serous pericardium - The serous pericardium is a thinner membrane that forms a
double layer around the heart.
oThe outer parietal layer: it is fused to the fibrous pericardium.
oThe inner visceral layer is also called the epicardium helps the layers of the heart wall to
adheres tightly to the surface of the heart

8. Layers of the Heart
• The heart wall consists of three layers enclosed in the pericardium:
1. Epicardium - the outer layer of the wall of the heart and is formed by the visceral
layer of the serous pericardium.
2. Myocardium - the muscular middle layer of the wall of the heart and has excitable
tissue and the conducting system.
3. Endocardium-
 A middle concentric layer
 A subendocardial layer.

9. Structure and Function
• Right atrium
• Left atrium
• Right ventricle
• Left ventricle

11. Heart Valves
tricuspid
valve
mitral
valve
/bicuspid
valve
aortic
valve
pulmonary
valve
Atrioventricular valves
Semilunar valves

12. Blood Supply
• Left main coronary artery carries 80% of the
flow to the heart muscle.
 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.
• Right coronary artery: branches supply the right
ventricle, right atrium, and left ventricle's inferior
wall.

13. Venous drainage and Lymphatics
Brachiocephalic nodes, in front of brachiocephalic veins
Tracheobronchial nodes, located at the distal end of the trachea
Venous drainage is via the variable coronary veins and the coronary
sinus.
The lymphatic vessels drain mainly into:

14. Nerve Supply
The main control of the heart resides
with the medulla oblongata. There is
an area called the cardio acceleratory
centre, or pressor centre, in the upper
part of the medulla oblongata, and an
area called the cardioinhibitory centre,
or depressor centre, in the lower
part. Together they are called the
cardio regulatory centre, since they
interact to control heart rate, etc.

15. Nerve Supply The sympathetic nervous system acts on the
sinoatrial node, speeding up the depolarization
rate, and therefore increasing the heart rate
The parasympathetic system works in
reverse in order to slow the heart rate down
The heart itself has a natural pacemaker,
the sinoatrial node, which does not need a
nervous supply to function
The nervous supply to the heart
is autonomic, consisting of
both sympathetic and parasymp
athetic parts. The sympathetic
fibres arise from the pressor
centre, while the parasympathetic
fibres arise in the depressor
centre.

16. Conduction system of heart
Your cardiac conduction system contains specialized cells and nodes that control your
heartbeat. These are the:
• Sinoatrial node:
Your sinoatrial node is sometimes called your heart’s natural pacemaker. It sends the
electrical impulses that start the heartbeat.
Your autonomic nervous system controls how fast or slowly your SA node sends
electrical signals. This part of the nervous system directs hormones that control
your heart rate based on what you are doing. For example, your heart rate increases
during exercise and slows when you are asleep.

18. • Atrioventricular node
The atrioventricular node delays the SA node’s electrical signal. It delays the signal by
a consistent amount of time (a fraction of a second) each time.
The delay ensures that your atria are empty of blood before the contraction stops. The
atria are the heart’s upper chambers. They receive blood from your body and empty it
into the ventricles.
• Bundle of His (atrioventricular bundle)
 It is a branch of fibers (nerve cells) that extends from your AV node. This fiber bundle
receives the electrical signal from the AV node and carries it to the Purkinje fibers.
The bundle of His runs down the length of the interventricular septum, the structure
that separates your right and left ventricles.

19. • Purkinje fibers
The Purkinje fibers are branches of specialized nerve cells. They send electrical signals very
quickly to your right and left heart ventricles.
Your Purkinje fibers are in the subendocardial surface of your ventricle walls. The
subendocardial surface is part of the endocardium, the inner layer of tissue that lines your
heart’s chambers.
When the Purkinje fibers deliver electrical signals to your ventricles, the ventricles contract.
As they contract, blood flows from your right ventricle to your pulmonary arteries and from
your left ventricle to your aorta. The aorta is the body’s largest artery. It sends blood from
your heart to the rest of your body

20. Recapitulation
• What is the weight of the human heart?
• Explain the blood supply of heart.
• What are the layers of heart?
• What are the components involved in conduction system of heart?
• Name the atrioventricular valves.

21. Conclusion
The heart is an essential, powerful organ that constantly pumps
oxygen and nutrients around the body. If a person is born
with congenital heart disease, or if damage occurs due to illness or
other factors, the heart’s function may diminish, and this can lead
to life threatening complications, such as heart failure. If the heart
stops, a person cannot survive for long. Staying active and
maintaining a healthful diet are two ways to protect the heart

22. Bibliography
1. Ross and Wilson. Anatomy and physiology.12th edition. Toronto;
Elsevier:2014. p. 87-92
2. https://www.slideshare.net/binuenchappanal/anatomy-of-heart-65381385
3. https://www.physio-pedia.com/Anatomy_of_the_Human_Heart
4. https://my.clevelandclinic.org/health/body/21704-heart
5. https://www.texasheart.org/heart-health/heart-information-
center/topics/heart-anatomy/

23. Thank you!