<prompt> Which of the following is the most radiosensitive tissue?BrainBone marrowThyroidLiver  <response>: Tissues with highest mitotic activity are highly radiosensitive. The tissues with high radiosensitivity are lymphoid tissue, bone marrow, mucosa of the GIT and germinal tissue. Least radiosensitive tissues are: Bone least Brain, muscle and skin Effects of radiation in different tissues: Hematopoietic system: Lymphopenia Thrombocytopenia Bone marrow hypoplasia Vascular system: Thrombosis Ischemic damage Integumentary system Acutely: erythema, edema, blistering Chronic: potential for squamous cell carcinoma Cancers caused by radiation: Acute leukemia Papillary carcinoma Osteogenic carcinoma Ref: Rapid Review Pathology By Edward F. Goljan page 173. 