The heart is a cone-shaped muscular organ that pumps blood, characterized by its size and location within the mediastinum, with four chambers and both pulmonary and systemic circulation systems. It consists of three layers (endocardium, myocardium, epicardium) and is encased in a pericardial sac. Key functions include oxygenating blood, removing waste, and regulating its own impulses through a specialized conduction system.

1. THE HEART
THE HEART

2. • It is a cone-shaped hollow muscular organ which pumps blood to the
body and back.
• It has weight about 250-300 grams.
• Size is that of a fist: 12cm length, 8cm wide, 6cm thick
• Location: -in middle mediastinum.
-1/3rd to right of midsternal plane and 2/3rd to left of it.
-posterior to body of sternum and 2nd-6th costal cartilages.
-anterior to vertebral column at level of T5-T8
-superior to superior surface of diaphragm.

3. • Base -quadrilateral directed upward, backward and posteriorly
-made of –left atrium
--parts of right atrium
• Apex –directed forward, downward and to left
-made of –parts of left ventricle

4. • 4 Surfaces: sternocostal/anterior surface- consist of right ventricle, some right atrium, some left ventricle.
diaphragmatic/inferior surface- consist of left ventricle, some right ventricle.
left pulmonary surface- consist of left atrium and left ventricle.
right pulmonary surface- consist of right atrium.
• 4 Margins: right margin
left margin
inferior/ acute margin- between anterior and diaphragmatic surfaces
obtuse margin- between anterior and left pulmonary surfaces
• 4 Grooves: coronary sulci- divide atria from ventricles
interatrial groove- divide left and right atria
interventricular grooves - anterior
- posterior

5. FUNCTION
• Pumps blood throughout the body via the circulatory system.
• Supply oxygenated blood with nutrients to tissues.
• Remove carbon dioxide and other wastes therefore receive
deoxygenated blood from body.

6. HEART WALL
• The Heart has three layers from inside to
outside: endocardium, myocardium,
epicardium.
• All these are surrounded by a double-
membrane sac of Pericardium.

7. PERICARDIUM AND EPICARDIUM
• It has 2 components:
• 1) Fibrous pericardium- outer tough connective tissue
• 2) Serous pericardium- inner thin layer, has 2 layers – Parietal layer- line
inner surface of fibrous pericardium
--Visceral layer-
attached to heart {EPICARDIUM}
• In between these two present the pericardial cavity having serous fluid.
• It allow lubrication of heart for friction-free movements.
• Prevent overfilling of heart with blood.

8. MYOCARDIUM
• The middle layer of the heart wall, thickest
• Cardiac muscle- involuntary striated muscle tissue surrounded by
collagen.
• The cardiac muscle pattern- muscle cells swirl and spiral around
the chambers of the heart, with the outer muscles forming a
figure 8 pattern around the atria and around the bases of the
great vessels and the inner muscles, forming a figure 8 around
the two ventricles and proceeding toward the apex. This complex
swirling pattern allows the heart to pump blood more effectively

9. ENDOCARDIUM
• The innermost layer.
• Lining of simple squamous epithelium.
• Covers heart chambers and valves and is continuous with the
endothelium of the veins and arteries of the heart.
• Secrete Endothelin- regulate contraction of the myocardium.
• Conduction system is present here.

10. CHAMBERS
• Heart has 4 chambers divided by the grooves, septum and valves.
• Right Heart: right atrium and right ventricle
• Left Heart: left atrium and left ventricle
• There are interatrial septum, interventricular septum, and
atrioventricular septum.
• There are bicuspid (mitral) valve, tricuspid (bazian) valve, aortic valve and
pulmonary valve.

11. RIGHT HEART
• Right atrium is separated by right ventricle by atrioventricular septum and
tricuspid valve (ant., septal, post cusps).
• Right Atrium: has right auricle, pectinate muscles around wall
-has opening of inferior and superior vena cava, coronary sinus
- in interatrial septum, Fossa Ovalis is present.
• Right Ventricle: has papillary muscles
- has chordae tendineae which attach to tricuspid valve
-receive blood from right atrium and pass to pulmonary trunk
-semilunar pulmonary valve (right, left, ant. Cusps) is present at
opening of pulmonary trunk

12. LEFT HEART
• Left atrium is separated from left ventricle by atrioventricular septum and
bicuspid valve (ant , post cusps).
• Left Atrium: has left auricle, pectinate muscles around wall
- has opening of pulmonary veins carrying oxygenated blood
• Left Ventricle: has papillary muscles
- has chordae tendineae attached to bicuspid valve
-receive blood from left atrium and pass to aorta
-semilunar aortic valve (right, left, post cusps) is present at
opening of aorta
- wall is 3 times thicker than of right ventricle

14. CIRCULATORY SYSTEM
• It include heart, lungs and vessels.
• The Heart has double circulation: pulmonary circulation and
systemic circulation

15. PULMONARY CIRCULATION
• Begin from right ventricle ->> deoxygenated blood goes through pulmonary arteries ->> to lungs ->> oxygenation occur and
waste and carbon dioxide exhaled from body ->> oxygenated blood goes through pulmonary veins ->> to left atrium.

16. SYSTEMIC CIRCULATION
• Begin from left ventricle ->> oxygenated blood goes through
aorta ->> to body ->> transfer oxygen and nutrients to tissues
and become deoxygenated ->> deoxygenated blood goes
through inferior and superior vena cava and coronary sinus -
>> to right atrium.

17. CONDUCTION SYSTEM OF HEART
• Cardiac muscle cells have capacity of generating self-impulse.
• 1st Sino-Atrial Node: pacemaker, located at upper right corner of
right atrium, generate action potential and cause atrial systole.
• 2nd Atrio-Ventricular Node: located in right atrium near interatrial
septum, delay the signal.
• Between these 2 are present internodal pathways.
• 3rd Bundle of Hiss: AV bundle, located in interventricular septum, has
right and left bundle branches.
• 4th Purkinje Fibers: located in right and left ventricles, cause
ventricular systole.

18. CARDIAC CYCLE• Sequence of events that occurs when the heart beats.
• One cardiac Cycle is of 0.8 seconds.
• As the heart beats, it circulates blood through pulmonary and systemic
circuits of the body.
• There are two phases of the cardiac cycle: systolic and diastolic
• For 1st 0.1 sec. – atrial systole; rest 0.7 sec. – atrial diastole,
• after 0.1 sec, up to 0.3 sec. – ventricular systole; rest 0.5 sec. –
ventricular diastole
• Represented by ECG
• During systole- semilunar valves are open and atrioventricular valves are
closed. Closing of atrioventricular valves produce 1st heart sound ‘LUB’.
• During diastole- atrioventricular valves are open and semilunar valves
are closed. Closing of semilunar valves produce 2nd heart sound ‘DUB’.

20. VASCULATURE OF HEART
• Arteries:
• 1) Right coronary artery- supply right atrium and
posterior surface of both ventricles.
• Branches- marginal artery
- posterior interventricular artery
• 2) Left coronary artery- supply left atrium and ventricle.
• Branches- circumflex artery
- anterior interventricular artery

21. • Veins:
• Coronary sinus- receive blood from – great cardiac vein
- anterior cardiac vein
- middle cardiac vein
- small cardiac vein

22. INNERVATION
• Vagus nerve
• Sympathetic trunk
• These nerves form a network of nerves that lies over
the heart called the cardiac plexus.

23. CLINICAL CASES
• Heart Arrhythmia :
• Condition of irregular heart beat.
• Causes- Coronary artery disease.
-High blood pressure.
-cardiomyopathy
-Valve disorders.
-Electrolyte imbalances in the blood, such as
sodium or potassium.

24. • Cardiogenic Shock:
• condition in which heart suddenly can't pump enough blood to meet body's needs.
• Causes- damage to heart's right ventricle, which sends blood to lungs to receive oxygen.
- myocardial infarction
-pulmonary embolism
-pericardial tamponade
-sudden valvular regurgitation
-inability of heart muscle to work properly
-ventricular tachycardia.

25. • Keshan disease:
• congestive cardiomyopathy caused by a combination of dietary
deficiency of selenium and the presence of a mutated strain of
Coxsackievirus.
• Found in the areas with low selenium in the soil.
• Can cause- hypothyroidism, including extreme fatigue, mental
slowing, goiter, cretinism, and recurrent miscarriage

26. • Eisenmenger's syndrome:
• long-standing left-to-right cardiac shunt in interventricular
septum caused by a congenital heart defect causes pulmonary
hypertension
• Result into- Cyanosis
-High red blood cell count
-clubbed finger tips
-Heart failure
-Abnormal heart rhythms
-Iron deficiency
-Kidney problems
-Stroke

27. THANK YOU
-AKSHMALA SHARMA