Blood and Circulation: Diseases and Components
Anemia
The main symptoms accompanying anemia are fatigue and loss of vitality. These symptoms are a direct consequence of a deficient supply of oxygen to the blood cells. Anemia is characterized by a low amount of hemoglobin, either because the red blood cell concentration is low, or because the amount of hemoglobin they contain is below what is usually considered sufficient. A balanced diet is crucial for preventing and managing anemia.
Leukemia
Leukemia is a form of cancer that affects cells in the bone marrow, the organ responsible for manufacturing blood. It is manifested by an increased number of white blood cells in the blood, but these cells are unable to fight infections. Additionally, the number of red blood cells and platelets decreases.
Hemophilia
Hemophilia is an inherited disease that is manifested by the appearance of bleeding, which can be spontaneous or caused by a blow or wound. It is due to problems in the coagulation of the blood. Platelets are responsible for initiating the process of blood clotting. For it to take place normally, it also requires the collaboration of 12 different substances, called plasma coagulation factors. Hemophiliacs lack one of these factors, so that coagulation is much slower. To alleviate these problems, it is necessary to inject the affected person with the missing factor.
Capillaries
Capillaries are very small diameter vessels, sometimes smaller than a hair. They form dense networks within organs that connect the two circulatory routes: arterial and venous. The capillary wall is extremely thin and allows exchanges between the blood and cells.
Arteries
Arteries are the tubes that carry blood from the heart towards the organs. Their walls are strong with powerful muscles, and also elastic. Blood circulates at high pressure inside the arteries, coming from the heart. Arteries branch and become finer.
Veins
Veins carry blood from the organs to the heart. Their walls are much thinner than the arteries. Blood circulates at low pressure inside the veins, going to the heart. This occurs due to the presence of valves that prevent backflow, and muscle contraction is used to facilitate forward movement. Numerous thin veins that collect blood from organs drain into veins, growing thicker as they approach the heart.
Pulmonary Circuit (Lesser Circuit)
Blood leaves the right ventricle through the pulmonary artery and is directed towards the lungs. There, gas exchange occurs between the alveoli and the capillaries in the infinite branching arteries. The blood picks up oxygen and loses carbon dioxide, and then returns to the heart through the pulmonary veins, reaching the left atrium.
Systemic Circuit (Greater Circuit)
Blood leaves the left ventricle through the aorta and reaches all organs. It distributes oxygen and nutrients needed for activity through the capillaries, while collecting waste products. The capillaries from the various organs converge into veins that return blood to the heart, entering the right atrium.
Arteriosclerosis
Arteriosclerosis is a hardening of the arteries that occurs when plaques formed essentially by fat and cholesterol are deposited inside these vessels. The plaque narrows the lumen of the artery and makes the wall harder and rougher. Platelets adhere to the rough surface and form clots that can clog an artery.