John Garfield (real name Julius Garfinkle) was an American actor. He was born in 1913 at New York and died in 1952 of a coronary thrombosis. Research John Garfield
Noah Beery Jr was an American actor. He was born in 1913 at New York and died in 1994 of cerebral thrombosis. He is perhaps best known for playing the father, 'Rocky Rockford' in the 1970's television series 'The Rockford Files'. Research Noah Beery Jr
Like all body organs, the heart needs a supply of blood to bring it oxygen. It cannot get oxygen from the blood within its chambers, which passes through too quickly and under too great a pressure, and in the right side is very low in oxygen. Instead, the muscle that makes up the wall of the heart, the myocardium, receives oxygen-rich blood from a system of small arteries that branch from the aorta. These are called the coronary arteries. They cross over the hearts surface, dividing and sending tiny branches into the heart muscle. The two coronary arteries are no wider than a drinking straw.
The right coronary artery lies in a groove between the right atrium and right ventricle and loops around the lower side and to the rear of the heart like a crown. Hence the name, coronary. This artery supplies blood to the thick muscle of the right ventricle.
On the other side, the left coronary artery divides almost immediately into two large branches, one of which (the anterior descending branch) passes over the front of the heart toward the tip. The other branch (the circumflex branch) lies in a groove between the left atrium and left ventricle. This artery supplies blood to the muscle of the left ventricle. The anterior descending branch supplies the front surface and tip of the heart and the front part of the septum. The circumflex branch supplies the portion of the left ventricular wall away from the septum. From the large coronary vessels, smaller branches arise, which divide and insert into the heart muscle, supplying its nutritional needs. If a blood clot occludes some part of the coronary artery, as in coronary thrombosis or coronary embolism, the cells of the heart are deprived of oxygen and soon die. This is called myocardial infarction. Research Coronary Artery
The wall of the heart is composed of cardiac muscle tissue, referred to as
myocardium. This tissue is similar to the voluntary muscles of the body. In the cardiac tissue, however, the elongated muscle cells are highly interconnected to assure the maintenance of a coordinated and orderly heartbeat. The medical term myocarditis refers to inflammation of the heart muscle. A very smooth tissue, endocardium, lines the interior chambers of the heart. This lining helps to reduce any friction that may be caused by blood that is constantly moving through the four hollow chambers of the heart. Endocarditis is an inflammation of the heart lining. This condition can cause rough spots to develop in the endocardium, which may lead to thrombosis. Research Myocardium
Blood may escape from the blood vessels as a result of injury. Capillaries are fractured by simple abrasion, veins with their very fragile walls are easily torn, while arteries are usually injured by a cut, either accidental or intentional. Infective or malignant disease, as it eats its way through tissues, may invade the wall of a blood vessel which subsequently gives way allowing free escape of blood. In the case of capillaries and veins, the inflammatory process involving the vessel usually sets up thrombosis so that haemorrhage does not occur. With arteries, while thrombosis may sometimes occur as the result of the inflammation, severe haemorrhage frequently follows erosion.
Perhaps the most common site of such arterial haemorrhage is in the base of a gastric ulcer. Because of the inflammation in the walls of the artery which may be coursing through the base of the ulcer, the vessel is prevented from contracting, and when it bursts the hole is held rigidly open with resultant severe and sometimes fatal haematemesis (vomiting of blood). High blood pressure is frequently associated with disease of the walls of the arteries, which lose their elasticity. In most parts of the body, the arteries are surrounded by fairly firm tissues which tend to support them, but this is not the case in the brain which is the most common site for the rupture of small arteries. Such cerebral haemorrhage is responsible for one form of apoplexy. The wall of an artery may be weak from injury, from congenital defect or from disease, and instead of it bursting it develops a large bulge which continues to increase in size as the years go by. The surrounding tissues become eroded by the continuous beating of the artery and eventually the stretched-out thin-walled sac bursts. This arterial bulge is known as aneurism. A congenital form occurs near the base of the brain. Aneurism follows gun-shot wounds in the region of arteries and the aorta undergoes a similar change as the result of arterio-sclerosis or syphilis. Research The Cause of Bleeding
Thrombocytopenic purpura is a bleeding condition in which there is a shortage of platelets due to excessive destruction. It is treated by removing the spleen (splenectomy). Occasionally blood transfusion is required at such an operation, but there is very little risk of bleeding being excessive since the number of platelets in the blood rises rapidly once the spleen, which has been destroying them, is removed. In fact, the number of platelets circulating in the blood for the few days following the operation may become so excessive that spontaneous thrombosis may occur in veins. Research Thrombocytopenic Purpura
Thrombosis is the formation of a clot within a blood vessel. If blood vessels have been damaged by inflammation (from the spread of infection in the surrounding tissues) or if their walls are thickened and rough from arteriosclerosis, clotting may start within the vessel while the blood is still circulating through it. Very soon the clot becomes piled up on the walls of the vessel and the tube becomes completely blocked. Once this clotting process has started it spreads rapidly up and down the vessel, blocking the mouths of the little branches, and consequently the blood how to or from the part affected becomes completely obstructed. If it is an artery which is blocked by this process, gangrene may supervene very rapidly. Arterial thrombosis occurs frequently in the coronary arteries of the heart: the heart muscle is deprived of oxygen and the patient collapses; if the clotting extends to one of the bigger vessels of the coronary circulation, the patient dies. If a vein becomes affected and arterial blood is still being pumped into the part, the tissues become greatly swollen and painful.
Venous thrombosis occurs perhaps most commonly in the veins of the leg following operation, leading to the formation of an oedematous leg which is called 'white leg'. If part of the clot within the vessel becomes detached and carried on into the circulation, it is known as an ' embolus', and will be carried to distant parts, blocking smaller vessels. Blood emboli travelling in the venous circulation pass through the right side of the heart into the pulmonary artery and thence into the smaller arterioles of the lungs. If a large pulmonary artery is blocked this condition of pulmonary embolism produces sudden death. The area of the lung which has been deprived of its blood supply is an infarct. A small infarct is compatible with life. The surrounding area of lung becomes inflamed and an area of pleurisy develops. Research Thrombosis
A tourniquet is a bandage or piece of rubber tubing used for stopping the flow of blood through a part of the body, generally a limb. Owing to the fact that the main arteries for the limbs are for the most part surrounded by muscle, any attempt to compress them with a tourniquet must involve: (a) A very tight constricting force. (b) Simultaneous compression of muscles and nerves. (c) Complete ischaemia (bloodlessness) of all the tissues beyond the point of application of the tourniquet. Risks of applying a tourniquet are therefore: 1. Insufficient compression of the artery but occlusion of the vein only, leading to congestion and increased bleeding from the ends of the cut veins. 2. Peripheral nerve injury and subsequent paralysis. 3. If the tourniquet remains in position too long, ischaemia and damage to muscles resulting in their contracture. 4. Damage to the artery wall, especially if it is already affected by arterio-sclerosis. Subsequent arterial thrombosis may occur.
In severe injuries where there has been considerable muscle damage, there is one distinct advantage in the application of a tourniquet. It prevents the return to the circulation of the histamine products of tissue damage, and as long as a tourniquet is in position there is less likelihood of severe surgical (secondary) oligaemic shock. Immediately the tourniquet is removed however, these substances reach the general circulation and the onset of oligaemic shock may be very rapid. In operations upon the limbs, a surgeon is able to work in a bloodless field by means of a suitably applied tourniquet. Research Tourniquet
The tunica interna, is a thin layer only a few cells thick of a vein and artery. It is sometimes referred to as the intima membrane. It is this layer that gives smoothness to the lining of the vessel, enhancing blood flow. It is through this tunica interna that nutrients reach the deeper parts of the media. With the passage of time the tunica interna of major arteries become coated with atheromatous plaques. These plaque deposits vary in size and shape. At a relatively early stage, these plaques consist of little lumps or nodules of scartissue in the tunica interna. In the centre of each nodule is a small cavity containing a yellowish, soft material known as cholesterol. Over time, the nodules may enlarge and protrude into the artery increasing the risk of total blockage of the vital artery (thrombosis). Atheromatous deposits also weaken the walls of the arteries causing them to bulge (aneurysm) and eventually rupture. Research Tunica Interna
The Probert Encyclopaedia was designed, edited and programed by
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Abbreviations
Research John Garfield
