The document provides an overview of the anatomy and physiology of the heart. It discusses the location of the heart in the thoracic cavity. It describes the layers of the heart - epicardium, myocardium, and endocardium - and the functions of each layer. It outlines the four chambers of the heart and their roles in blood flow. It explains the cardiac cycle of diastole and systole. It provides details on the heart valves and conducting system. It concludes by listing and briefly defining several important heart conditions.

1. HEARTDr. SaBa Qureshi

3. CONTENTS
➤ Definition
➤ Location of heart
➤ Function of heart
➤ Different layers of heart
➤ Functions of different layers of
heart
➤ Chambers of heart
➤ Valves of heart
➤ Functions of the valves of the heart
➤ Blood flow and cardiac cycle of
heart
➤ conducting system of heart

4. DEFINITION
➤ The heart is a muscular organ
about the size of a fist

5. LOCATION OF
HEART➤ in thoracic cavity
➤ posterior to the sternum
➤ superior to the diaphragm
➤ between the lungs

6. CARDIOVASCULA
R SYSTEM➤ The heart pumps blood
through the network of arteries
and veins called the
cardiovascular system.

7. FUNCTION
➤ The heart pumps oxygen and
nutrient rich blood supply to
the organs, tissues and cells of
the body, and eliminates
waste products

8. DIFFERENT
LAYERS OF
HEART
➤ The heart wall is made of 3
layers
➤ Epicardium
➤ Myocardium
➤ Endocardium

9. EPICARDIUM
➤ Epicardium (epi-cardium) is
the outer layer of the heart
wall.
➤ It is also known as visceral
pericardium as it forms the
inner layer of the pericardium.
The epicardium is composed
primarily of loose connective
tissue, including elastic fibers
and adipose tissue.

10. FUNCTIONS OF
EPICARDIUM➤ The epicardium functions to
protect the inner heart layers
and also assists in the
production of pericardial fluid.
➤ This fluid fills the pericardial
cavity and helps to reduce
friction between pericardial
membranes.
➤ Also found in this heart layer
are the coronary blood
vessels, which supply the
heart wall with blood.

11. MYOCARDIUM
➤ Myocardium (myo-cardium) is the
middle layer of the heart wall.
➤ It is composed of cardiac muscle
fibers, which enable heart
contractions.
➤ The myocardium is the thickest
layer of the heart wall, with its
thickness varying in different parts
of the heart.
➤ The myocardium of the left
ventricle is the thickest as this
ventricle is responsible for
generating the power needed to
pump oxygenated blood from the
heart to the rest of the body.

12. ENDOCARDIUM
➤ Endocardium (endo-cardium)
is the thin inner layer of the
heart wall.
➤ This layer lines the inner heart
chambers, covers heart valves
and is continuous with the
endothelium of large blood
vessels.
➤ The endocardium of heart atria
consists of smooth muscle, as
well as elastic fibers.

13. CHAMBERS OF
HEART➤ The heart has four chambers
➤ The right atrium
➤ The right ventricle
➤ The left atrium
➤ The left ventricle

14. ➤ The right atrium receives blood from the veins and pumps it to
the right ventricle.
➤ The right ventricle receives blood from the right atrium and
pumps it to the lungs, where it is loaded with oxygen.
➤ The left atrium receives oxygenated blood from the lungs and
pumps it to the left ventricle.
➤ The left ventricle (the strongest chamber) pumps oxygen-rich
blood to the rest of the body. The left ventricle’s vigorous
contractions create our blood pressure.

15. VALVES OF THE
HEART➤ The heart has 4 valves
➤ Tricuspid valve: located
between the right atrium and
the right ventricle.
➤ Pulmonary valve: located
between the right ventricle and
the pulmonary artery.
➤ Mitral valve: located between
the left atrium and the left
ventricle.
➤ aortic valve: located between
the left ventricle and the aorta

16. CARDIAC CYCLE
➤ The cardiac cycle is the
sequence of events that
occurs when the heart beats.
➤ 1st Diastole Period
➤ 1st Systole Period
➤ 2nd Diastole Period
➤ 2nd Systole Period

17. FIRST DIASTOLE
➤ During the first diastole period,
the atria and ventricles are
relaxed and the atrioventricular
valves are open.
➤ Oxygen-depleted blood
returning to the heart from the
body passes through the
superior and inferior vena
cavae and flows to the right
atrium.
➤ The open atrioventricular valves
(tricuspid and mitral valves)
allow blood to pass through the
atria to the ventricles.

18. FIRST SYSTOLE
➤ At the beginning of the first systole
period, the right ventricle is filled with
blood passed on from the right
atrium.
➤ The ventricles receive impulses from
fiber branches (Purkinje fibers),
which carry electrical impulses to the
ventricles causing them to contract.
➤ As this occurs, the atrioventricular
valves close and the semilunar
valves (pulmonary and aortic valves)
open.
➤ Ventricular contraction causes
oxygen-depleted blood from the right
ventricle to be pumped to the
pulmonary artery.

19. SECOND
DIASTOLE➤ In the second diastole period, the
semilunar valves close and the
atrioventricular valves open.
➤ Oxygenated blood from the
pulmonary veins fills the left atrium
(blood from the venae cavae is also
filling the right atrium at this time). .
➤ Atrial contraction causes the left
atrium to empty its contents into the
left ventricle (the right atrium is also
emptying blood into the right ventricle
at this time).
➤ The mitral valve, located between the
left atrium and left ventricle, prevents
oxygenated blood from flowing back
into the left atrium.

20. SECOND
SYSTOLE➤ In the second diastole period, the
semilunar valves close and the
atrioventricular valves open.
➤ Oxygenated blood from the
pulmonary veins fills the left atrium
(blood from the venae cavae is also
filling the right atrium at this time). .
➤ Atrial contraction causes the left
atrium to empty its contents into the
left ventricle (the right atrium is also
emptying blood into the right ventricle
at this time).
➤ The mitral valve, located between the
left atrium and left ventricle, prevents
oxygenated blood from flowing back
into the left atrium.

21. SOME IMPORTANT
HEART CONDITIONS
➤ There are some important
heart conditions that are given
in next slides that must be
known to medical students

22. CORONARY
ARTERY
DISEASE
➤ Coronary artery disease: Over
the years, cholesterol plaques
can narrow the arteries
supplying blood to the heart.
The narrowed arteries are at
higher risk for complete
blockage from a sudden blood
clot (this blockage is called a
heart attack)

23. STABLE ANGINA
PECTORIS➤ Stable angina pectoris:
Narrowed coronary arteries
cause predictable chest pain
or discomfort with exertion.
The blockages prevent the
heart from receiving the extra
oxygen needed for strenuous
activity. Symptoms typically
get better with rest

24. UNSTABLE
ANGINA
PECTORIS
➤ Unstable angina pectoris:
Chest pain or discomfort that
is new, worsening, or occurs at
rest. This is an emergency
situation as it can precede a
heart attack, serious abnormal
heart rhythm, or cardiac arrest.

25. MYOCARDIAL
INFARCTION➤ Myocardial infarction (heart
attack): A coronary artery is
suddenly blocked. Starved of
oxygen, part of the heart
muscle dies

26. ARRHYTHMIA
➤ Arrhythmia (dysrhythmia): An
abnormal heart rhythm due to
changes in the conduction of
electrical impulses through the
heart. Some arrhythmias are
benign, but others are life-
threatening

27. CONGESTIVE
HEART FAILURE➤ Congestive heart failure: The
heart is either too weak or too
stiff to effectively pump blood
through the body. Shortness of
breath and leg swelling are
common symptoms

28. CARDIOMYOPAT
HY➤ Cardiomyopathy: A disease of
heart muscle in which the
heart is abnormally enlarged,
thickened, and/or stiffened. As
a result, the heart's ability to
pump blood is weakened.

29. MYOCARDITIS
➤ Myocarditis: Inflammation of
the heart muscle, most often
due to a viral infection.

30. PERICARDITIS
➤ Pericarditis: Inflammation of
the lining of the heart
(pericardium). Viral infections,
kidney failure, and
autoimmune conditions are
common causes

31. PERICARDIAL
EFFUSIOY➤ Pericardial effusion: Fluid
between the lining of the heart
(pericardium) and the heart
itself. Often, this is due to
pericarditis.

32. ATRIAL
FIBRILLATION➤ Atrial fibrillation: Abnormal
electrical impulses in the atria
cause an irregular heartbeat.
Atrial fibrillation is one of the
most common arrhythmias.

33. PULMONARY
EMBOLISM➤ Pulmonary embolism:
Typically a blood clot travels
through the heart to the lungs

34. HEART VALVE
DISEASE➤ Heart valve disease: There are
four heart valves, and each
can develop problems. If
severe, valve disease can
cause congestive heart failure

35. HEART
MURMURS➤ Heart murmur: An abnormal
sound heard when listening to
the heart with a stethoscope.
Some heart murmurs are
benign; others suggest heart
disease.

36. ENDOCARDITIS
➤ Endocarditis: Inflammation of
the inner lining or heart valves
of the heart. Usually,
endocarditis is due to a
serious infection of the heart
valves.

37. SUDDEN
CARDIAC DEATH➤ Sudden cardiac death: Death
caused by a sudden loss of
heart function (cardiac arrest)

38. CARDIAC
ARREST➤ Cardiac arrest: Sudden loss of
heart function