3. The body’s largest organ is the size of six tennis courts, yet is only one cell thick
The smooth lining of more than 60,000 miles of blood vessels, known as the ‘Endothelium’ would cover 6 tennis courts if they were removed from the human body and flattened!
The role of the endothelium is to act as a barrier to control substances that can pass fom the blood into the wall of the arteries. They help regulate blood pressure, fight off disease, control blood clotting and fine-tunes the blood so it flows easily around the body.