heart anatomy

1. Anatomy
of the heart
MCH – DR.Jaydeep

4. Heart Anatomy
 Size, Location, and Orientation
 Enclosed in the mediastinum
 Base (posteriorsuperior portion)
and Apex (inferioranterior portion)

5. Heart Anatomy
 Coverings
 Pericardium
 protects the heart
 anchors the heart to
surrounding structures such as
the diaphragm and the great
vessels
 prevents overfilling of the heart
with blood

6. Heart Anatomy
Coverings
 pericardial cavity contains a film of
serous fluid
 pericarditis: inflammation of the
pericardium which may lead to
adhesions between the layers or
the buildup of fluid in the pericardial
cavity (cardiac tamponade)

7. Heart Anatomy
 Heart Wall
 Epicardium
 Myocardium
 bulk of the heart consisting
mainly of cardiac muscle

8. Heart Anatomy
 Heart Wall
 Endocardium
 simple squamous epithelium
and a thin CT layer that lines the
heart chambers and valves and
is continuous with the
endothelial lining of the blood
vessels

9. Heart Anatomy
 Chambers
 Atria
 Features
 small, thin-walled chambers
 Functions
 receiving chambers for blood
returning to the heart from the
circulation
 push the blood into the adjacent
ventricles.

10. Heart Anatomy
 Chambers
 Atria
 Receive blood from
 right side
 Superior and Inferior Vena Cava
 Coronary Sinus (draining the
myocardium)
 left side
 Pulmonary Veins

11. Heart Anatomy
 Chambers
 Ventricles
 Features
 make up most of the mass of the
heart
 the walls of the left ventricle are
3X thicker than those of the right

12. Heart Anatomy
 Chambers
 Ventricles
 Functions
discharging chambers of the heart
propel blood to Pulmonary Trunk (right
ventricle), Aorta (left ventricle)

14. Heart Anatomy
 Pathway of Blood Through the Heart
 Pulmonary Circuit
 functions strictly as gas exchange
 the right side of the heart is the
pulmonary circuit pump
 this is a short, low-pressure circuit

15. Heart Anatomy
 Pathway of Blood Through the Heart
 Systemic Circuit
o functions as both gas and nutrient
exchange
o the left side of the heart is the
systemic circuit pump
o this is a long, high-resistance
pathway through the entire body

16. Heart Anatomy
 Heart Valves
 These enforce the one-way flow of
blood through the heart
 The valves open and close in response
to differences in blood pressure on
their two sides

17. Heart Anatomy
 Heart Valves
 Atrioventricular Valves
 the valves close when the ventricular
pressure increases and forces blood
against the valve flaps
 Tricuspid (right side)
 Bicuspid (Mitral) (left side)

18. Heart Anatomy
 Heart Valves
 Semilunar Valves
 located between the ventricles and
the large arteries
 these open when the pressure
produced by the contracting ventricle
exceeds that in the artery and close
when the arterial pressure exceeds
the pressure produced by the
relaxing ventricle
 Pulmonary (right side)
 Aortic (left side)

20. Coronary Circulation
 Coronary Arteries
 the coronary arteries arise from the
base of the aorta and actively deliver
blood only when the heart is relaxed
 the heart is 0.5% of body weight and
receives 5% of the body's blood supply
(most to the left ventricle)

21. Coronary Circulation
 Coronary Arteries
 left main coronary artery
 left anterior descending artery:
serves the interventricular septum
and anterior walls of both ventricles
 circumflex artery: serves the left
atrium and posterior wall of the left
ventricle

22. Coronary Circulation
Coronary Arteries
 Right main coronary artery
 posterior descending artery: serves the
posterior walls of both ventricles
 marginal artery: lateral wall of the right
side of the heart
 Cardiac Veins follow arteries and join at
the Coronary Sinus which empties blood
into the right atrium

24. Heart Physiology
 Electrical Events
 Intrinsic Conduction System of the
Heart
 the ability of cardiac muscle to
depolarize and contract is intrinsic
(no nervous stimulation is required)
 nerve impulses can alter the basic
rhythm of heart activity set by
intrinsic factors

25. Heart Physiology
 Electrical Events
 Action Potential Generated by
Autorhythmic Cells
 Sequence of Excitation
o Sinoatrial Node
o Atrioventricular Node
o Atrioventricular Bundle (bundle of
His)
o Bundle Branches
o Purkinje Fibers

26. Heart Physiology
 Electrical Events
 Extrinsic Innervation of the Heart
 fibers of autonomic nervous system
accelerate or inhibit the basic rate of
heartbeat set by the intrinsic
conduction system

27. Heart Physiology
 Electrical Events
 Electrocardiography
 electrical currents generated and
transmitted through the heart spread
throughout the body and can be
monitored
 the graphic recording of electrical
changes during heart activity is
called an electrocardiogram (ECG or
EKG)

28. SA
AV

29. Thank You