Hemostasis commands special attention among physicians and investigators. The importance and appeal of this discipline rests on exciting scientific advances as well as its obvious clinical relevance. The mechanisms underlying the initiation and control of blood coagulation constitute a complex but beautifully integrated system of cellular and molecular interactions that fulfill a biological function of crucial importance. As summarized in Chapter 1, the circulation of blood cells and plasma through the vascular tree is essential for providing the body's organs and tissues with nutrients and oxygen and for defense against infection and inflammation. Platelets, endothelial cells, and coagulation proteins cooperate in a complex and dynamic way to repair leaks in the vasculature and protect against hemorrhage in a high-pressure circulatory system.
From the Hulton Getty Collection
Prince Leopold (left) and Sir William Jenner (right)
A solid understanding of the pathophysiology of blood coagulation is essential in the practice of both medicine and surgery. Thrombosis is the leading cause of death in developed countries, impacting a broad range of common medical problems including diabetes, obesity, myocardial infarction, stroke, and pulmonary embolization.
From the state archives of the Russian Federation, Moscow
Prince Alexei and his mother
Clinical and laboratory investigation of congenital bleeding disorders have been crucial in working out the structure and function of the blood clotting proteins. The two most famous patients with hemophilia are descendants of Queen Victoria. They are shown in the photographs on the right, convalescing from acute bleeding episodes. On the upper right, the queen's son, Prince Leopold of Albany, is attended by the celebrated British physician Sir William Jenner. Below, Prince Alexei, czarevitch of all the Russias and great-grandson of the queen, is attended by his mother, Czarina Alexandra.