Final answer:
A blood clot that originates in the leg and travels to the lung is known as a pulmonary embolism (PE), which is a serious, potentially fatal condition that must be treated immediately.
Step-by-step explanation:
A blood clot that forms in a blood vessel in the leg and then travels to a blood vessel in the lung is best described as a pulmonary embolism (PE). This occurs when a clot, medically known as a deep vein thrombosis (DVT), breaks free forming an embolus, moves through the bloodstream, and lodges within a pulmonary artery. The pulmonary arteries are responsible for transferring deoxygenated blood from the heart to the lungs for oxygenation. The presence of a clot can block this essential flow of blood, leading to serious complications or even death.
The formation of a thrombus involves an aggregation of platelets, erythrocytes, and WBCs trapped within fibrin strands. Once a thrombus detaches and becomes an embolus, it can travel to major organs, potentially resulting in life-threatening conditions such as pulmonary embolism, heart attack, or stroke. It is a medical emergency requiring immediate attention.