All rights reserved. A simple question deserves a simple answer. How many cells are in your body? Unfortunately, your cells can't fill out census forms, so they can't tell you themselves. Some types of cells are easy to spot, while others—such as tangled neurons—weave themselves up into obscurity. Even if you could count ten cells each second, it would take you tens of thousands of years to finish counting.
An estimation of the number of cells in the human body
Blood - Production of red blood cells (erythropoiesis) | Britannica
Bone marrow contains two types of stem cells: hemopoietic which can produce blood cells and stromal which can produce fat, cartilage and bone. Red blood cells, platelets and most white blood cells arise in red marrow; some white blood cells develop in yellow marrow. Red marrow is found mainly in the flat bones such as hip bone, breast bone, skull, ribs, vertebrae and shoulder blades, and in the cancellous "spongy" material at the proximal ends of the long bones femur and humerus. In cases of severe blood loss, the body can convert yellow marrow back to red marrow in order to increase blood cell production.
Human erythrocytes or red blood cells RBCs are the primary cellular component of blood. They are involved in oxygen transport through the body and have features that distinguish them from every other type of human cell. Adult humans have roughly trillion RBCs at any given time, comprising approximately one quarter of the total number of human cells. RBCs are disc-shaped with a flatter, concave center. This biconcave shape allows the cells to flow smoothly through the narrowest blood vessels.
To screen for or diagnose a variety of conditions that can affect the number of white blood cells WBCs , such as an infection , inflammation or a disease that affects WBCs; to monitor treatment of a disorder or to monitor therapy that is known to affect WBCs. As part of a complete blood count CBC , when you have a routine health examination; when you have signs and symptoms that may be related to a condition affecting the number of WBCs; when you have a condition or are receiving treatment that is known to affect WBCs. White blood cells, also called leukocytes, are cells that exist in the blood, the lymphatic system , and tissues and are an important part of the body's defense system.