Three cell populations in the body that do not routinely undergo cell division are?
The correct answer and explanation is:
Three cell populations in the body that do not routinely undergo cell division are neurons, muscle cells (specifically cardiac and skeletal muscle), and red blood cells (RBCs).
- Neurons: Once fully differentiated, neurons in the central nervous system (CNS) and peripheral nervous system (PNS) do not typically divide. These cells are highly specialized to transmit electrical signals and are considered post-mitotic. Although some regions in the brain, like the hippocampus, have shown a limited capacity for neurogenesis (the formation of new neurons), the majority of neurons do not undergo cell division after they have matured.
- Muscle Cells: Muscle cells, particularly cardiac and skeletal muscle cells, are also non-dividing cells. Skeletal muscle fibers are multinucleated and are formed during development from precursor cells known as myoblasts. After these cells fuse to form a muscle fiber, they do not divide again. While there is a small capacity for regeneration in skeletal muscle via satellite cells (which are dormant muscle stem cells), the muscle fibers themselves do not divide. Similarly, cardiac muscle cells (cardiomyocytes) do not divide postnatally. Instead, the heart’s ability to repair itself after injury is limited.
- Red Blood Cells (RBCs): Red blood cells do not divide once they are fully mature. These cells are derived from hematopoietic stem cells in the bone marrow and undergo differentiation into erythrocytes. Once mature, RBCs lose their nucleus and other organelles to make more room for hemoglobin, the protein responsible for oxygen transport. Since they lack a nucleus and are specialized for a specific function, RBCs cannot divide. Their lifespan is around 120 days, after which they are removed by the spleen and liver.
In summary, neurons, muscle cells, and red blood cells are specialized cells that do not routinely undergo cell division. Their lack of division is due to their differentiation into highly specialized forms that are tailored to their specific functions within the body.