Which organ system response to whole-body radiation exposure has a threshold dose of 1 Gray (Gy)?

The correct response relates to the hemopoietic syndrome, which specifically affects the bone marrow and blood cell production. This organ system's response to whole-body radiation exposure has a threshold dose of approximately 1 Gray (Gy). At this dose, the radiation can significantly impair the bone marrow's ability to produce blood cells, leading to potential life-threatening conditions such as anemia, increased susceptibility to infections, and bleeding disorders due to low platelet counts.

The threshold for hemopoietic syndrome is crucial to understanding the biological effects of radiation exposure on the hematopoietic system. When the radiation dose exceeds this threshold, the individual may experience symptoms related to a decrease in blood cell lineages, including possible death if the exposure is sufficiently high and not managed properly.

Other organ systems, such as those involved in gastrointestinal and cerebrovascular syndromes, have differing threshold doses for their onset and are related to much higher levels of radiation exposure or different biological effects. Understanding these thresholds is critical for assessing the effects of radiation exposure in medical and emergency contexts.