Wednesday, December 2, 2015

What are Red Blood Cells?

Red blood cells(erythrocytes) are biconcave discs. They have no nucleus. Their diameter is about 7 micrometers.Their main function is gas transport mainly oxygen. They also carry some carbon dioxide. The biconcavity increases their surface area for gas exchange. The thin central portion allows fast entry and exit of gases.The cells are flexible so they can squeeze through narrow capillaries. They contain no intracellular organelles thereby giving more room for haemoglobin (the large pigmented protein responsible for gas transport).