Healthy Notes

Heart 1. Location and Size The heart is situated in the mediastinum (central compartment of the thoracic cavity), slightly tilted to the left. It is about the size of a closed fist and weighs approximately 250–300 grams in adults. 2. Structure and Layers of the Heart Layers : Pericardium : A double-layered sac that encases the heart. Outer fibrous pericardium protects and anchors the heart. Inner serous pericardium consists of the parietal and visceral (epicardium) layers. Epicardium : The outermost layer of the heart wall, part of the serous pericardium. Myocardium : The thick, muscular middle layer responsible for contractions. It contains cardiac muscle fibers arranged in a spiral pattern. Endocardium : The innermost layer, which lines the chambers and valves, and is continuous with blood vessels. 3. Heart Chambers Right Atrium : Receives deoxygenated blood from the superior and inferior vena cava, as well as from the coronary sinus. Right Ventric...

Cardiovascular System The cardiovascular system , also called the circulatory system , is responsible for circulating oxygen (O₂)🔵, nutrients 🍎, hormones 💉, and waste products 🚮 throughout the body. It ensures that tissues receive adequate oxygen supply and metabolic waste is removed efficiently. ANATOMY OF THE CARDIOVASCULAR SYSTEM 1️⃣ The Heart: The Central Pump 🔹 The heart is a muscular organ , about the size of a fist, located slightly left of the sternum in the mediastinum. 🔹 It beats 60-100 times per minute at rest and pumps about 5 liters of blood per minute . 💡 Structure of the Heart 🔸 The heart has four chambers : ✅ Right Atrium (RA) 🏠 – Receives deoxygenated blood 🔴 from the body via the superior and inferior vena cava . ✅ Right Ventricle (RV) 🏠 – Pumps blood to the lungs 🌬️ via the pulmonary artery . ✅ Left Atrium (LA) 🏠 – Receives oxygenated blood 🔵 from the lungs via the pulmonary veins . ✅ Left Ventricle (LV) 💪 – Pumps ...