Heart

thingiverse

The human heart beats as a sturdy muscle located within the chest cavity, positioned centrally between the lungs and encased by a double-walled sac known as the pericardium. This vital organ weighs approximately 250-300 grams, with its average size equivalent to the palm of an adult hand. In terms of structure, the human heart is divided into four chambers - the upper right and left atria, which serve as blood receptacles, and the lower right and left ventricles that act as powerful pumps. The superior and inferior vena cavae enter the upper chambers on the backside, returning oxygen-depleted blood to the heart for replenishment with life-giving oxygen. A complex network of cardiac valves regulates the flow of blood within these four compartments, directing deoxygenated blood towards the lungs while oxygen-rich blood flows to various organs throughout the body via an extensive arterial system. Meanwhile, pressure gradients created by both the atria's and ventricles' contractions propel blood in rhythmic pulsations through an intricately intertwined vascular network.