Cardiology may be a medical science that's involved with the structure and function of the heart and circulatory system, and also the diagnosing and treatment of patients with cardiovascular diseases. Physicians who specialize in this field of medicine are referred to as cardiologists, a specialty of internal medicine. Physicians who specialize in cardiac surgery are known as cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery. Cardiology is split into many fields like pediatric cardiology, adult cardiology, interventional procedures, electrophysiology and echocardiography etc. Although the circulatory system is inextricably coupled to blood, cardiology is comparatively unconcerned with haematology and its diseases. Some obvious exceptions that have an effect on the occupation of the heart would be blood tests, remittent oxygen carrying capability and coagulopathies.