Definition of Heart
Heart ek muscular pumping organ hai jo body me blood circulate karta hai. Ye ek hollow, four-chambered organ hai jo continuously oxygenated aur deoxygenated blood ko pump karta hai taaki body ke cells ko oxygen aur nutrients mil sakein.
Location of Heart
● Heart thoracic cavity me, mediastinum ke beech me situated hota hai.
● Ye sternum ke piche aur lungs ke beech me hota hai.
● Thoda left side me tilted rehta hai.
● Approximate size: Closed fist jitna.
● Weight: 250–300 gm (female) aur 300–350 gm (male).
External Structure of Heart
Heart ke surface par 3 major grooves (sulci) hote hain:
1. Atrioventricular groove (coronary sulcus) →atria aur ventricles ke beech.
2. Interatrial groove →Dono atria ke beech.
3. Interventricular groove→Dono ventricles ke beech.
● Heart ke surface ko pericardium protect karta hai.
Coverings of Heart
1. Pericardium: Double-layered covering hoti hai.
i. Fibrous pericardium: Outer tough layer – heart ko protect karta hai.
ii. Serous pericardium: Inner double membrane layer.
→ Parietal layer: Fibrous pericardium ke andar.
→ Visceral layer (Epicardium): Directly heart ke upar.
● In dono ke beech pericardial cavity hoti hai jisme pericardial fluid present hota hai (friction kam karta hai).
Chambers of Heart
Heart me 4 chambers hote hain:
1. Right Atrium:
● Deoxygenated blood receive karta hai from body (via superior and inferior vena cava).
● Blood ko right ventricle me bhejta hai.
2. Right Ventricle:
● Deoxygenated blood ko pulmonary artery ke through lungs me bhejta hai for oxygenation.
3. Left Atrium:
● Lungs se oxygenated blood receive karta hai (via pulmonary veins).
● Blood ko left ventricle me bhejta hai.
4. Left Ventricle:
● Oxygenated blood ko aorta ke through pure body me pump karta hai.
● Iska wall sabse thick hota hai (powerful contraction ke liye).
Valves of Heart
Valves ensure karte hain ki blood sirf one direction me flow kare:
1. Tricuspid valve
● Right atrium aur right ventricle ke beech.
2. Pulmonary valve
● Right ventricle aur pulmonary artery ke beech.
3. Bicuspid (Mitral) valve
● Left atrium aur left ventricle ke beech.
4. Aortic valve
● Left ventricle aur aorta ke beech.
Ye valves chordae tendineae aur papillary muscles ke support se function karte hain.
Blood Supply of Heart
Heart ka khud ka blood supply coronary arteries se hota hai.
Right coronary artery (RCA)
● Right atrium, right ventricle aur SA node ko supply karti hai.
Left coronary artery (LCA)
● Left anterior descending (LAD) branch aur circumflex branch me divide hoti hai.
● Left atrium, left ventricle aur interventricular septum ko supply karti hai.
● Venous return coronary sinus ke through right atrium me jata hai.
Conducting System of Heart
Heart me impulse generate aur conduct hone ke liye ek electrical system hota hai:
1. SA Node (Sinoatrial Node)
● Natural pacemaker, impulse initiate karta hai.
2. AV Node (Atrioventricular Node)
● Impulse delay karta hai taaki atria contract kar sakein.
3. Bundle of His
● Impulse ventricles tak le jata hai.
4. 4. Right & Left Bundle Branches
● Ventricular walls tak impulse distribute karte hain.
5. Purkinje Fibers
● Impulse ko ventricles me spread karte hain for contraction.
Functions of Heart
● Blood ko pump karna (oxygenated and deoxygenated circulation).
● Nutrients aur oxygen ko cells tak pahunchana.
● Waste products (CO₂) ko lungs tak bhejna.
● Blood pressure maintain karna.
● Endocrine control (Atrial natriuretic peptide secretion).
Summary Anatomy Of Heart
Heart ek four-chambered muscular organ hai jo continuous blood circulation ke liye responsible hai. Iske major parts hain chambers, valves, pericardium, aur coronary vessels. SA node heart ka pacemaker hai jo rhythmic contractions control karta hai. Healthy lifestyle aur balanced diet se heart function maintain kiya ja sakta hai.
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