An overview of Red blood cells (01).pptx

The following is an overview on the information about red blood cells.
Erythrocyte. Their composition. Function. Properties. Significance etc.

1. RED BLOOD CELLS Red blood cells ( RBCs ) or erythrocytes (e- RITH -ro¯-sı¯ts; erythro- red; -cyte- cell) contain the oxygen-carrying protein hemoglobin, which is a pigment that gives whole blood its red c olor. A healthy adult male has about 5.4 million red blood cells per microliter of blood, and a healthy adult female has about 4.8 million. (One drop of blood is about 50 microL .) To maintain normal numbers of RBCs , new mature cells must enter the circulation at the astonishing rate of at least 2 million per second, a pace that balances the equally high rate of RBC destruction.

2. RBCs lack a nucleus and other organelles and can neither reproduce nor carry on extensive metabolic activities. The cytosol of RBCs contains hemoglobin molecules; these important molecules are synthesized before loss of the nucleus during RBC production and constitute about 33% of the cell’s weight RBC ANATOMY DIAMETRE VOLUME WIDTH [at wider end] WIDTH [at narrower end] : 7-8 micrometre : 90-95 cubic micrometre : 2-5 micrometre . : 1 micrometre RBCs lack a nucleus and other organelles and can neither reproduce nor carry on extensive metabolic activities. The cytosol of RBCs contains hemoglobin molecules; these important molecules are synthesized before loss of the nucleus during RBC production and constitute about 33% of the cell’s weight .

3. RBC PHYSIOLOGY Red blood cells are highly specialized for their oxygen transport function. A biconcave disc has a much greater surface area for the diffusion of gas molecules. Each RBC contains about 280 million hemoglobin molecules. A hemoglobin molecule consists of a protein called globin , composed of four polypeptide chains (two alpha and two beta chains); a ring like non protein pigment called a heme is bound to each of the four chains. At the center of each heme ring is an iron ion (Fe2 ) that can combine reversibly with one oxygen molecule.

4. Origin, development, and structure Of blood cells

5. ANKYRIN PROTEIN COMPOSITION OF RBC They are enucleated . They are devoid of nucleus, ribosomes, mitochondria. They have haemoglobin in cytosol. [ Hb makes upto 33 % of cell weight] They contain enzymes like, carbonic anhydrase . They have proteins like, glycophorins , ankyrins , spectrins .

6. PROPERTIES OF RBC Respires anaerobically. Does not consume ATP, due to absence of mitochondria. Doesn't divide, due to absence of nucleus. Undergoes cellular deformation to navigate across various microcirculation vessels. Their life span is 120 days.

7. FUNCTIONS OF RBC Transports haemoglobin. Facilitates transport of carbon dioxide and oxygen. Responsible for most of the acid base buffering power of whole blood. Helps in regulation of blood pressure.

8. PRODUCTION OF RBC During embryonic life : in yolk sac During mid trimester : liver, spleen, lymph nodes Last 5 months of - pregnancy a nd after birth : bone marrow Until 5 years of growth : Bone marrow of all bones Around 20 years of age : mostly produced by membranous bones eg. Sternum, ribs, ilia and vertebrae.

9. RBC INDICES

10. HOMEOSTATIC REGULATION OF RED BLOOD CELL FORMATION

11. REFERENCES Dr. Gerard J. Tortora & Bryan Derrickson’s PRINCIPLES OF ANATOMY AND PHYSIOLOGY, 15th Edition. Wiley Publishers, 2017. Kim E. Barrett, Susan M. Barman, Heddwen L. Brooks & Jason Yuan’s Ganong’s Review of Medical Physiology. 26th Edition, McGraw-Hill Education/ Medical Publisher,2019. Dr. John and Michael E. Hall's Guyton and Hall Textbook of Medical Physiology. Third South Asia Edition. Dr. AK Jain's Manual Of Practical Physiology. 5th Edition

12. THANK-YOU Presented by Bhumika Srivastava