Question

Where are Red Blood Cells, produced? What is the average life span of a RBC?

Answer 1

Red blood cells are produced in the bone marrow. Mature RBC's have a life span of approximately 120 days.

Explanation:

Red blood cells are produced in the bone marrow . Stem cells in the bone marrow develop in several steps to mature red blood cells (RBC):

stem cells `->` progenitor cells `->` precursor cells (blasts) `->` mature cells (see image below).

It takes about 21 days for a stem cell to develop in the bone marrow into a so called reticulocyte. This cell is released into the blood stream and circulates there for 1 to 2 days before it is developed into a mature RBC (erythrocyte).

Once they are matured, an RBC remains functional in the bloodstream for about 110 to 120 days before it is degraded.