The mammalian red cell is further adapted by lacking a nucleus—the amount of oxygen required by the cell for its own metabolism is thus very low, and most oxygen carried can be freed into the tissues. The biconcave shape of the cell allows oxygen exchange at a constant rate over the largest possible area.

It was known that as a mammalian red blood cell nears maturity, a ring of actin filaments contracts and pinches off a segment of the cell that contains the nucleus, a type of “cell division.” The nucleus is then swallowed by macrophages (one of the immune system’s quick-response troops).

Unlike most other eukaryotic cells, mature red blood cells don’t have nuclei. When they enter the bloodstream for the first time, they eject their nuclei and organelles, so they can carry more hemoglobin, and thus, more oxygen.

Unlike red and white blood cells, platelets are not actually cells but rather small fragments of cells. Platelets help the blood clotting process (or coagulation) by gathering at the site of an injury, sticking to the lining of the injured blood vessel, and forming a platform on which blood coagulation can occur.

Below are 8 important facts about blood.

• Blood Is Fluid Connective Tissue.
• Blood Provides the Body’s Cells with Oxygen and Removes Carbon Dioxide.
• Blood Transports Nutrients and Hormones.
• Blood Regulates Body Temperature.
• Platelets Clot Blood at Sites of Injury.
• Blood Brings Waste Products to the Kidneys and Liver.

Blood volume According to a 2020 article , there are around 10.5 pints (5 liters) of blood in the average human adult body, although this will vary depending on various factors. During pregnancy, a woman may have up to 50% more blood.

All blood products taken from the blood bank must be hung within 30 minutes and administered (infused) within 4 hours due to the risk of bacterial proliferation in the blood component at room temperature.