- Red blood cells (erythrocytes) transport oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. They develop from stem cells in the bone marrow in a multi-step process called erythropoiesis.
- Mature red blood cells are biconcave disks that are flexible and can change shape, allowing them to flow through narrow blood vessels. They contain the protein hemoglobin which binds oxygen and gives blood its red color.
- Red blood cells have an average lifespan of 120 days, after which they are broken down and recycled. Around 2.5 million new red blood cells are produced every second to replace those that die off.
11. Energy Flow and Law of Mass Balance All living processes require constant input of energy Where from? - How is it stored? How is it used to do work? Total amount of substance in body = intake + production - output What substances are maintained through law of mass balance? Major routes for output? Major routes for input?
24. Composition of Blood Blood consist of 1 Red cell 2 White cell 3 Platelets 4 Plasma – in which the above elements are suspended Plasma is the liquid component. which contain soluble fibrinogen Serum is what remains after the formation fibrin clot Dr Alamzeb MBBS M.Phil
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26. BLOOD. Blood is also vital to maintain a stable body temperature by varying the amount of blood to different areas of the body. To do all this, the heart pumps about 2,000 gallons (9100 liters) of blood per day; its valves operate some 5000 times per hour , and it never stops for maintenance...not even once! The Bible said a long time ago that " the life of the flesh is in the blood ." Dr Alamzeb MBBS M.Phil
39. Size at thin point 1 micron at thinnest point The average volume of the red blood cell is 90 to 95 cubic micrometers. Dr Alamzeb Dr Alamzeb MBBS M.Phil
41. Thickness continue A sheet of paper is approximately 75 micron thick Therefore 10 Erythrocytes could be aligned side by side across the edge of a sheet paper Dr Alamzeb MBBS M.Phil
42. Shape of RBCs Under Microscope Red blood cells (erythrocytes) shown above in a stained slide. Note how they stain darker at the edges than in the middle reflecting their biconcave shape. Dr Alamzeb MBBS M Phil
43. Appearance under microscope Red blood cells (erythrocytes) shown in a stained slide. Note how they stain darker at the edges than in the middle reflecting their biconcave shape.
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50. Change of shape As you can see by the above photomicrograph red blood cells in life are highly deformable and are able to squeeze through minute gaps.
86. Chemical reaction CO2 + H2O H2CO3 H + + HCO 3- Carbonic Anhydrase carbon dioxide + water carbonic acid + hydrogen ion + bicarbonate ion Alamzeb MBBS M.Phil
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Editor's Notes
10 or 11 depending on whether muscles and skeleton are considered one system. Also: Lymphatic system is anatomical system, physiologically it belongs to circulatory, digestive and immune systems. Regulation of plasma concentration: The endocrine system acts on bones, kidneys, and intestine to ensure that plasma calcium concentrations remain within a certain range.