Monocytes
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Monocytes are formed in the red bone marrow from monoblasts. After exiting the bone marrow, where unlike granulocytes they do not form a marrow reserve, monocytes circulate in the blood from 36 to 104 hours, and then leave in the tissues. 7 × 10 6 monocytes leave the blood in the tissue for 1 h . In tissues, monocytes differentiate into organo- and tissue-specific macrophages. The extravascular pool of monocytes is 25 times greater than the circulating one.
The system of mononuclear phagocytes unites various types of cells involved in the protective reactions of the body. Macrophages play an important role in the processes of phagocytosis. They remove from the body dying cells, remnants of destroyed cells, denatured protein, bacteria and Arg-AT complexes. Macrophages are involved in the regulation of hematopoiesis, immune response, hemostasis, lipid and iron metabolism.
Reference values of absolute and relative monocytes in blood
Age |
Absolute amount, × 10 9 / l |
Relative quantity,% |
12 months |
0.05-1.1 |
2-7 |
4 years |
0-0.8 |
2-7 |
10 years |
0-0.8 |
1-6 |
21 year |
0-0.8 |
1-8 |
Adults |
0-0.8 |
1-8 |
The causes of increase and decrease in monocytes
What do need to examine?
What tests are needed?