Regulation of Erythropoiesis
Have you ever wonder how your red blood cells are regulated in your body? What happened if they are less or more? Let’s take some time to read about how your hardworking cells, red blood cells do their job!
ERYTHROPOEISIS Erythropoiesis is a process to form red blood cells in the bone marrow. Bone marrow is the erythrocyte factory that fills the internal cavities of bones.
During early stages of embryo, erythrocytes are produced by the yolk sac and then by the spleen during the third month of gestation, until the seventh month it takes place in bone marrow.
REGULATION OF ERYTHROPOIESIS
Thinking logically people always think that because of the function of erythrocytes is to transport oxygen in the blood, the stimulus for erythropoeisis is low oxygen levels. They would be correct, but low oxygen levels do not stimulate erythropoiesis by acting directly on the bone marrow.
Hence, it stimulates kidneys to secrete erythropoietin (hormone) into the blood, and this hormone will stimulate the production of erythrocytes in the bone marrow.
This rapid in erythropoietin secretion increase the number of red blood cells in the circulation, as also contribute to raising oxygen carrying capacity of the blood and restoring oxygen deliver to the body tissues into normal condition. Once the oxygen level in the tissues is return to normal, erythropoietic activity is inhibited.
EXAMPLE OF CONDITIONS AFFECTING ERYTHROPOEISIS
High altitude
When we are in a high place such as mountain, partial pressure of oxygen in air less and oxygen transport to tissues are decreased. This will lead to tissue hypoxia.
Cardiac failure
The patient with heart failure will experienced inefficient pumping of blood. It will decreased blood flow to peripheral vessels and also lead to hypoxia.
Lung disease
The person with lungs failure will decrease absorption and diffusion of gases such as oxygen in blood. As a result, blood carry less oxygen and also lead to hypoxia.
Hypoxia acts as a symptom of decreased oxygen in tissues. This stimulus will stimulate the kidneys to secrete erythropoietin into the blood. Erythropoietin then will stimulate erythropoiesis and increase its production in the bone marrow. As the number of red blood cells increase, it also contribute to raising oxygen carrying capacity of the blood and restoring oxygen deliver to the body tissues into normal condition (homeostasis). When homeostasis achieved, erythropoietin secretion is stopped.
For better understanding, sit back and watch this interesting video!
REFERENCES LINK
1. http://www.interactive-biology.com/3969/erythropoiesis-formation-of-red-blood-cells/
2. http://www.uptodate.com/contents/regulation-of-erythropoiesis
3. https://www.youtube.com/watch?v=aE4d7JS-TTQ
4. https://youtu.be/DJg-Q94A2cQ