Question

The process of formation of RBCs is called
(a)Pathogenesis
(b)Erythropoiesis
(c)Glycogenesis
(d)None of the above

Answer 1

Hint: In the fetus, this process occurs in the yolk sac, liver, and spleen whereas post-birth occurs in the bone marrow. The production of the RBC is regulated by a hormone secreted in the kidney called erythropoietin.

Complete answer:
Erythropoiesis is the process of formation of the red blood cells (RBCs). It is the process by which the erythropoietic stem cell gets developed into a mature red blood cell.
Erythropoiesis is stimulated by the reduced amount of oxygen in the circulation, that gets detected by the kidneys, which in turn will secrete the hormone erythropoietin. This hormone will stimulate the proliferation and the differentiation of the precursor red cells, which triggers the enhanced erythropoiesis in the hemopoietic tissues, which will ultimately produce the red blood cells. In mammals, erythropoiesis will generally occur in the red bone marrow. Increased physical activity might cause an increase in erythropoiesis.

Additional Information: -RBCs lack a nucleus, mitochondria, ribosomes, and other organelles.
-This allows the accumulation of hemoglobin in RBCs which is essential for the transport of oxygen to peripheral tissues.
-Each hemoglobin consists of one globin group bounded by four heme groups which form a tetrahedral arrangement.
-The heme group consists of a porphyrin ring bonded with iron. To each iron atom present in the heme group, 1 oxygen molecule can bind which will eventually be transported to the other parts of the body by the blood.
-The globin portion of hemoglobin is degraded to its elemental amino acids which are sent to the bone marrow to be used for the new RBC synthesis.
- The iron in the heme part of hemoglobin is stored in the spleen/liver and is recycled for new RBC synthesis.
-The non-iron heme part of hemoglobin is reduced to bilirubin which is utilized for bile production in the liver.
So, the correct answer is ‘erythropoiesis’.

Note: The circulating RBCs are highly susceptible to mutations leading to its damage. During the blood circulation, the RBCs will become old and accumulate irreparable damage. The life span of RBC is 120 days after which it becomes senescent and will be degraded by the splenic macrophages and is called the graveyard of RBCs.