Question

How many red blood cells are in the human body?

Answer 1

Hint: The red bone marrow of our body generates approximately 2.4 million new RBCs per second that circulates for nearly about 100-120 days. The number of cells that are composition of a human body is 70% red blood cells.

Complete answer:
These RBCs or red blood cells are the principal means for oxygen transportation in our body via blood flow in the circulatory system.
The cytoplasm of RBC helps to carry haemoglobin that can bind with oxygen and carry it around as well as gives the blood its red colour.
-These are biconcave disc-shaped cells that shows absence of a nucleus and most of the organelles to keep a required amount of space for the haemoglobin molecules.
The red bone marrow of our body generates these cells in a huge number of quantities (2.4 million new cells per second) and after 100-120 days they get recycled in the spleen.

1.Adult humans transport 20-30 trillion RBCs at a time which composes nearly 70% of all cells by number.
2.Certain diseases may lead to decrease in the number of RBC in the blood such as Anemia, hemolysis, etc.
The RBC count and number in an adult man per mm3 of blood is 4,600,000-5,000,000. In females, the number of RBCs are 4,200,000- 5,000,000 per cubic mm of blood. The count also differs in different ages. In new-borns, the number of RBCs is the highest i.e. 4.8-7.2 million and in children 3.8-5.5 million per cubic mm of blood.

Note: The process of red blood cell development in red bone marrow is termed as erythropoiesis through which the cells develop from stem cells to mature red blood cells and it takes about 7 days. This process is increased by the EPO hormone. The aged blood cells, at the last get removed from the blood by the spleen, liver, or lymph nodes.