- Erythrocytes or red blood cells are the most well-known components of the whole blood. They contain hemoglobin, a complex protein, which contains iron. This helps red blood cells to carry oxygen through the body. And this is the main function of erythrocytes. When hemoglobin concentrations fall down and there is no sufficient amount of red blood cells to carry oxygen it is termed anemia. Iron is very important component of the erythrocytes because iron can bind oxygen and transport it to the tissues.
- The blood runs a certain path through the body. It moves through pulmonary circuit and then continues on through systemic circuit. Deoxygenated blood, which contains mostly carbon dioxide, enters the right atrium through superior vena cava (upper part of the body) and inferior vena cava (lower part of the body). From the right atrium blood runs to the right ventricle through right atrioventricular valve. Then deoxygenated blood moves through another valve to the pulmonary artery. It takes blood to the lungs and it becomes oxygenated. Such blood comes back to the heart through pulmonary veins. Actually, veins transfer the deoxygenated blood to the heart, except the pulmonary ones. Then blood enters the left atrium and then oxygenated blood drains into left ventricle through the valve. Then blood is pumped to the main artery – aorta. After aorta blood goes through the body. Capillaries connect small arteries and small veins. Valves pump blood through the heart.
- There are many factors that will affect blood flow. When the viscosity of blood increases it becomes thicker and flow decreases. It can happen because of diabetes, when blood contains abnormal amount of sugar. Blood flow can be also changes when blood vessels are blocked. Plaques can form on the walls of the blood vessels and slows down the blood flow.
- Cardiac conduction system is a group of muscle cells in the heart that send special signals to contract the heart. Cardiac arrhythmias are irregular conditions of the electrical activity of the heart. Tachycardia is a heart rate that exceeds the normal range or contracting speed. Bradycardia is a heart rate slower than the normal range. An ectopic pacemaker site in left or right atrium and starts the atrial premature beat outside the normal sinuatrial node. Eelectrocardiogram is an interpretation of the electrical activity of the heart detected by special equipment. SA node is an impulse-generating tissue at the right atrium of the heart .
- Cardiovascular system is a system that regulates the blood circulation through the body. Capillaries, veins and arteries transport the blood. Veins transport deoxygenated blood, arteries blood with oxygen and capillaries bridge the smallest veins and arteries.
American Heart Association. (2013). Retrieved from http://www.heart.org/HEARTORG/
American National Red Cross. (2013). Whole blood and red blood cells. Retrieved from http://www.redcrossblood.org/learn-about-blood/blood-components/whole-blood-and-red-blood-cells
Simon H (2013, March 18). Anemia. The New York Times. Retrieved from http://health.nytimes.com/health/guides/disease/anemia/diagnosis.html