Different components of human blood are replaced at different rates. According to the AABB, a non-profit organization that represents organizations that conduct blood transfusions, plasma is replaced within a few hours of a blood donation while the red blood cells take a few weeks to replace. Doctors usually only remove about one pint of blood during a transfusion, which represents about 10 percent of the total blood volume.Know More
According to Palomar Community College, human blood contains approximately 4,000 different components. These are replaced on a regular basis by different processes in the body. For example, bone marrow produces stem cells which in turn produce red blood cells. Red blood cells live for about 4 months before they are removed and recycled by the spleen. White blood cells, by contrast, only last an average of 18 to 36 hours before they are removed. Occasional white blood cells last for up to 1 year before they are removed. Platelets, which help to form clots, only survive about 10 days before they are removed from the blood stream.
People are usually able to donate blood every 56 days. Blood donations are an important component of health care systems because to date, no synthetic substitute exists, according to the AABB.Learn more about Blood
Blood is responsible for transporting oxygen, carbon dioxide, nutrients, hormones and proteins in the body, according to KidsHealth. The blood also carries glucose, ions, amino acids and waste products, such as urea, through the body. Red blood cells carry hemoglobin, a chemical that gives blood its red color.Full Answer >
White blood cells help fight infections in the body by attacking pathogens, such as bacteria and viruses, after they invade the bloodstream. Healthline states that these cells are formed in the bone marrow and circulate throughout the bloodstream to fight and attack pathogens.Full Answer >
The shedding of clots occurs when menstrual blood is expelled rapidly from the body during the period, according to WebMD. This rapid expulsion does not allow adequate time for the anticoagulants released by the body to prevent blood from clotting.Full Answer >
Dark-colored blood, called venous blood, is dark because it has become deoxygenated after having traveled through the body before returning to the heart drained of oxygen. Blood leaving the heart, called arterial blood, is pumped from the lungs back to the heart by the pulmonary artery, and it contains a large amount of oxygen for delivery around the body. Arterial blood, therefore, appears a brighter red than deoxygenated venous blood.Full Answer >