Topics:
Animal Physiology, Animal Refresher
Principal Erythroid Growth Factor
The principal erythroid growth factor is:
- Erythropoietin — Correct Answer
- Vitamin B12
- Thyroxin
- Folic acid
Explanation:
Correct Answer: Erythropoietin
Erythropoietin (EPO) is the principal erythroid growth factor (haemopoietin). It is a glycoprotein hormone secreted primarily by the peritubular interstitial cells of the kidney (and to a lesser extent by the liver) in response to hypoxia (low oxygen levels in the blood).
Role of Erythropoietin
- Stimulates proliferation and differentiation of erythroid progenitor cells in the bone marrow.
- Promotes survival of erythroid precursors by inhibiting apoptosis.
- Increases reticulocyte release from bone marrow into the bloodstream.
Distinction: Growth Factor vs. Maturation Factor
| Type | Factors | Function |
|---|---|---|
| Growth factor | Erythropoietin, haemopoietin growth factor, thyroxin | Stimulates production and proliferation |
| Maturation factors | Vitamin B12, Folic acid, Intrinsic factor (Castle) | Required for DNA synthesis and nuclear maturation |
Why Other Options Are Wrong
- Vitamin B12 & Folic acid → These are maturation factors, not the primary growth factor.
- Thyroxin → It has a supportive role in stimulating erythropoiesis generally but is not the principal erythroid growth factor.
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
