2 Flashcards
What is erythropoiesis?
The process of development of red blood cells from pluripotent stem cells, taking about 7 days.
What are the two main features of erythropoiesis?
Formation of haemoglobin inside the cell and maturation of the cell.
What happens to the cell during maturation?
The cell decreases in size and loses its nucleus.
What factors influence the maturation of red blood cells?
The presence of vitamin B12 and folic acid.
Where are vitamin B12 and folic acid absorbed?
Vitamin B12 is absorbed in the terminal ileum, while folic acid is absorbed in the duodenum and jejunum.
What is the role of intrinsic factor?
Intrinsic factor is a glycoprotein secreted by parietal cells that helps in the absorption of vitamin B12.
What is haemoglobin?
A complex protein consisting of globin and an iron-containing substance called haem, synthesised inside developing erythrocytes.
What is the function of haemoglobin in mature erythrocytes?
Haemoglobin combines with oxygen to form oxyhaemoglobin, transporting oxygen around the body.
How many atoms of iron are in each haemoglobin molecule?
Each haemoglobin molecule contains four atoms of iron.
What triggers increased erythropoiesis?
Hypoxia, or deficient oxygen supply to body cells.
What is the primary stimulus for erythropoiesis?
Hypoxia, which can occur due to reduced oxygen-carrying power of blood or reduced oxygen tension in the air.
What hormone stimulates erythropoiesis?
Erythropoietin, mainly produced by the kidneys.
What is the result of increased erythropoiesis?
An increase in the production of proerythroblasts and red blood cell numbers.
