What are human red blood cells?
1 Answer
Human red blood cells are present in liquid connective tissue called blood. Mature cells circulate through out body along blood vessels including heart and capillaries.
Explanation:
Red blood cells are formed from stem cells present within red bone marrow of certain bones. The matured cells lose nuclei when released in circulation. This helps them to pack more of protein haemoglobin. This protein is made up of four subunits and iron; due to presence of pyrrol ring the protein is coloured. Red colour of haemoglobin makes the RBCs red. As millions of such cells are present in circulation, blood also appears red in colour.
Haemoglobin is extremely important as it binds to 97%oxygen that the blood carries from lungs to tissues.
Haemoglobin also carries 23% of all carbon dioxide.
RBCs are disc shaped biconcave cells, with avg diameter of 7 micron in human. Other than mammals all vertebrates possess nucleated RBCs.
