Erythrocytes Flashcards
structural characteristics that contribute to it transport of gases
- Biconcave shape that has a huge surface area
relative to volume - high amount of hemoglobin / 97% hemoglobin
- Anaerobic respiration, to conserve oxygen
two main function of erythrocytes
- transport of gases
2. buffer blood pH
briefly describe the structure of hemoglobin
- Consists of two α and two β subunits of globin
- Each subunit binds to a heme group
- each globin subunit bind to one heme group
- Each heme group bears an atom of iron, which can bind to one oxygen molecule.
- hemoglobin transport 4 oxygen molecule
Erythropoiesis
refers specifically to erythrocytes production.
stem cell for erythrocytes is ……….
hemocytoblast
development of erythrocytes
- hemocytoblast
- proerythroblast
- erythroblast ( ribosome synthesis in early erythroblasts )
- normoblast ( – hemoglobin accumulation in late erythroblasts and normoblasts )
- reticulocytes ( ejection of the nucleus from normoblasts and formation of reticulocytes )
- erythrocyte ( Reticulocytes then become mature erythrocytes )
development of erythrocytes
- hemocytoblast
- proerythroblast
- erythroblast
- normablast
where is hemotopoiesis take place
the red bone marrow of epiphyses of the humerus and femur, and axial skeletal and girdles.
iron is stored in intracellular in the following proteins
- ferritin
2. hemosiderin
in circulating extracellular iron is loosely stored in protein called
transferrin
hormone that influence erythropoiesis and organ that produces it
erythropoietin and produced by the kidney
what triggers kidneys to produce erythropoietin ( EPO ) hormone
- hypoxia
erythropoietin mechanism
- reduction in oxygen/ hypoxia stimulates kidneys to produce erythropoietin.
- erythropoietin stimulates red bone marrow.
- red bone marrow produces erythrocytes through erythropoiesis.
- the level of oxygen is restored and the production of erythropoietin stops.
what is the differences btn hypoxia and hypoxemia
hypoxia is a low oxygen level in the body tissue while hypoxemia is a low oxygen level in the blood.
main causes of hypoxia
- hemorrhage or excess destruction of erythrocytes
- pneumonia
- vigorous physical exercises.