A child undergoing prophylactic irradiation as preparation for bone marrow transplantation (BMT) for treatment of acute lymphoblastic leukemia (ALL) requires consideration of the radiosensitivity of different cell types in the body.
Radiation sensitivity varies among different tissues based on their cell division rates and differentiation. Generally, cells that divide rapidly are more sensitive to radiation compared to those that do not.
Examining the options:
- Spermatogonia: These are rapidly dividing germ cells in the testes and are highly sensitive to radiation.
- Intestinal epithelial cells: These cells line the gastrointestinal tract and have high turnover rates, making them very sensitive to radiation.
- Neurons: Neurons are highly differentiated and do not typically undergo division in adulthood. Therefore, they are among the least affected by radiation.
- Bone marrow: Bone marrow contains hematopoietic stem cells that divide frequently, thus are very sensitive to radiation.
Given these considerations, neurons will be the least affected by the prophylactic irradiation because of their lack of division compared to the other cell types listed. Therefore, the correct answer is Neurons.