BIOB34H3 Lecture Notes - Bone Marrow, Erythropoiesis, Red Blood Cell
Document Summary
About 5 liters, about 8% of body weight. Is a connective tissue: formed elements, erythrocytes (rbcs, platelets leukocytes (wbcs, matrix is plasma. Functions: transport of o2, co2, nutrients, wastes, heat, hormones, protection, from wbcs and other defenses. Contains proteins, ions, buffers, respiratory gases, nutrients, wastes, hormones. Proteins are functionally important: establish osmotic pressure (holds water, three main types, albumins- bind substances for transport, globulins- bind substances for transport, blood clotting, inactive precursor molecules, antibodies fibrinogen- blood clotting. Occurs in red marrow: formation of blood cells (hematopoiesis, erythrocytes. Very small, about 8 m in diameter, can squeeze through even smaller capillaries. Mature cells have no nucleus or other organelles. Live about 120 days, most die in spleen capillaries. Contain hemoglobin: carries most of the oxygen, carries some carbon dioxide, helps buffer blood. Erythropoiesis (production of rbcs: controlled by hormone erythropoietin, which is released from the kidneys in response to low oxygen levels.
