When do rbc have a nucleus

All blood cells white, red, and platelets are produced from stem cells called hemocytoblasts located in bone marrow. It takes about 7 days for a stem cell to fully mature into a red blood cell that is prepared to be released into the bloodstream.

During this process, the stem cell becomes an immature red blood cell called an erythroblast. Then, the nucleus and mitochondria of the erythroblast disappear, and the immature cell is gradually filled with hemoglobin. At this point, the cell is called a reticulocyte. Finally, the cell becomes a full mature red blood cell and enters the blood, ready to transport oxygen throughout the body. The life of a red blood cell is short due to its lack of nucleus; human red blood cells only survive for about days.

When red blood cells are old or damage, they are ready to be eliminated from the bloodstream. Red blood cell removal is controlled by specialized cells called macrophages in the spleen part of the lymphatic system and the liver.

The spleen disposes of worn-out red blood cells and controls the amount of blood cells at work in the body. Additionally, the liver recycles iron from damaged red blood cells. Together, the macrophages in the spleen and liver remove old red blood cells from the body. Conditions that damage the bone marrow include blood cancers such as leukemia and lymphoma, tuberculosis, and certain fungal infections. Bone marrow damage or anemia may cause the body to compensate by making RBC in locations other than the bone marrow, for example in the liver or spleen.

These conditions can include leukemia, myeloid metaplasia scarring of the bone marrow , and polycythemia vera excessive RBC production. Sometimes nucleated RBC do slip out of the bone marrow in healthy humans. However, medical issues that affect the spleen can prevent this from happening.

Such issues include certain types of anemia, malaria, collagen vascular diseases, malignant neoplasms, and chemotherapy treatment. Copied to clipboard. Intrigued by immortality. March 16, Whitehead Institute scientists investigate germ cells — the cells that never cease to exist. Committed to reproduction.

November 21, Signaling factor seeking gene. September 24, However, they do contain numerous granules or vesicles. The hormone thrombopoietin, produced by the liver and kidneys, regulates the production of megakaryocytes and platelets. Platelets have different appearances in their inactivated and activated states. When inactivated , platelets are irregularly shaped discs. Activated platelets are spherical, with protrusions that allow them to stick to wound tissue and to other platelets to form a plug at the site of a blood vessel tear.

Activated platelets also release chemicals from their granules to initiate clotting. The life span of a platelet is about 10 days. Like red blood cells, old platelets are phagocytosed. Reserve platelets are stored in the spleen. When a blood vessel tears, platelets adhere to the damaged blood vessel wall near the tear, forming a platelet plug. At this point, they change from their inactive to their active shape, and they empty the contents of their granules.

At the site of an injury, the platelets connect to one another and release chemicals that stimulate blood clotting. Proteins called clotting factors form fibrin threads that, together with the platelets, form a clot.