Category: Cardiac Anatomy & Physiology

Introduction The cardiac cycle is the sequence of mechanical and electrical events that occur during a single heartbeat, enabling the heart to efficiently pump blood throughout the systemic and pulmonary circulations. Each cycle ensures unidirectional blood flow, optimal ventricular filling, and effective stroke volume. Understanding the cardiac cycle is fundamental to cardiology, physiology, and clinical…

The heart is not only a mechanical pump but also a complex organ intricately regulated by the autonomic nervous system (ANS). Cardiac innervation is crucial for maintaining proper heart rate, conduction velocity, contractility, and overall cardiovascular homeostasis. Understanding cardiac innervation involves examining the sympathetic and parasympathetic inputs, as well as the cardiac plexus, which serves…

Introduction The left coronary artery (LCA) is a pivotal vessel supplying the majority of the left heart, including the left ventricle (LV), left atrium (LA), and interventricular septum (IVS). Its branches — most importantly the left anterior descending (LAD) and the left circumflex (LCX) — have critical anatomical and clinical significance. A thorough understanding of…

Introduction The right coronary artery (RCA) is one of the two main coronary arteries supplying the myocardium. Arising from the right aortic sinus, the RCA runs along the right atrioventricular (AV) groove, giving off multiple branches that supply the right atrium, right ventricle, sinoatrial (SA) and atrioventricular (AV) nodes, and parts of the interventricular septum.…

Introduction The heart is a highly organized pump that relies on unidirectional blood flow to maintain efficient circulation. This directionality is enforced by the cardiac valves, which open and close in response to pressure gradients during the cardiac cycle. Broadly, these valves are divided into two categories: atrioventricular (AV) valves and semilunar valves. The AV…

1. Introduction The left ventricle (LV) is the thickest-walled chamber of the heart, responsible for pumping oxygenated blood into the systemic circulation via the aorta. Its anatomical design supports high-pressure output and efficient ejection of blood. Understanding LV anatomy is crucial for interpreting cardiac imaging, evaluating function, and managing cardiovascular diseases such as heart failure,…

Introduction The right ventricle (RV) is more than “the weaker cousin” of the left ventricle. Its form and internal architecture are uniquely adapted for handling venous return and delivering blood to the low-resistance pulmonary circulation. Three anatomical features — the overall shape of the chamber, the trabeculae carneae, and the moderator band (septomarginal trabecula) —…

The left atrium (LA) is one of the four chambers of the human heart and plays a crucial role in cardiac physiology. Its primary function is to receive oxygenated blood from the pulmonary veins and deliver it to the left ventricle, which then pumps the blood to the systemic circulation. Understanding the anatomy of the…

Introduction The right atrium (RA) is one of the four cardiac chambers and plays a crucial role in collecting systemic venous blood and channeling it into the right ventricle. It is often underestimated in its importance, yet its structural integrity, conduction system elements, and hemodynamic function are essential for maintaining normal cardiac output and rhythm.…

The human heart is one of the most fascinating and crucial organs in the body, tirelessly pumping blood day and night to sustain life. While most people think of the heart as a single muscle, it is actually a highly organized, layered structure designed for maximum efficiency, protection, and durability. Understanding the layers of the…