GROSS ANATOMY

Detailed explanation-1: -Cancer cells tend to divide quickly and grow out of control. Radiation therapy kills cancer cells that are dividing, but it also affects dividing cells of normal tissues. The damage to normal cells causes unwanted side effects.

Detailed explanation-2: -Lymphocytes (white blood cells) and cells which produce blood are constantly regenerating, and are, therefore, the most sensitive.

Detailed explanation-3: -Some cells, like blood and reproductive cells, divide more often than others. These types of cells are much more sensitive to radiation. For example, embryos contain a lot of rapidly dividing cells. As a result, they are very sensitive to radiation.

Detailed explanation-4: -Immature (undifferentiated) hematopoietic cells that have divided (proliferated) from stem cells are highly sensitive to radiation and die due to a small amount of radiation more easily than differentiated cells.

Detailed explanation-5: -The tissues most sensitive to radiation damage are those with rapidly dividing cells, like: Bone marrow and lymphatic system (which are constantly producing new blood cells).