Human body
Blood vessels carry blood throughout the body, which moves because of the beating of the heart. Venules and veins collect blood low in oxygen from tissues throughout the body. These collect in progressively larger veins until they reach the body's two largest veins, the superior and inferior vena cava, which drain blood into the right side of the heart. From here, the blood is pumped into the lungs where it receives oxygen and drains back into the left side of the heart. From here, it is pumped into the body's largest artery, the aorta, and then progressively smaller arteries and arterioles until it reaches tissue. Here blood passes from small arteries into capillaries, then small veins and the process begins again. Blood carries oxygen, waste products, and hormones from one place in the body to another. Blood is filtered at the kidneys and liver.
Coronary artery ectasia
Coronary artery ectasia is a rare disease that occurs in only 0.3-4.9% of people in North America. Coronary artery ectasia is characterized by the enlargement of a coronary artery to 1.5 times or more than its normal diameter. The disease is commonly asymptomatic and is normally discovered when performing tests for other conditions such as coronary artery disease, stable angina and other acute coronary syndromes. Coronary artery ectasia occurs 4 times more frequently in males than in females and in people who have risk factors for heart disease such as smokers. While the disease is commonly found in patients with atherosclerosis and coronary artery disease, it can occur by itself and in both cases it can cause health problems. The disease can cause the heart tissue to be deprived of blood and die due to decreased blood flow, and blockages due to blood clots or spasms of the blood vessel. This blood flow disruption can cause permanent damage to the muscle if the deprivation is prolonged. Coronary artery ectasia also increases the chance of developing large weak spots in the affected coronary arteries, or aneurysms that can rupture and result in death. The damage can result in angina which is pain in the chest and is a common complaint in these patients.