What is the expected outcome of Gastrointestinal Syndrome from significant radiation exposure?

Gastrointestinal Syndrome occurs as a result of high doses of radiation, typically above 1 Gray (Gy). The primary effects manifest in the gastrointestinal tract due to the rapid turnover of epithelial cells in that area, which are highly sensitive to radiation. When the cells lining the intestines are damaged or destroyed by the radiation, it results in several symptoms, including loss of appetite, nausea, vomiting, diarrhea, and lethargy.

Lethargy is brought on by the overall systemic effects of radiation exposure, as the body struggles to maintain homeostasis amidst the damage. Loss of appetite is a direct consequence of the gastrointestinal distress caused by the compromised epithelial cells, leading to decreased food intake and energy levels. The symptoms reflect the body's inability to process food properly and manage hydration, resulting in a general downturn in health status.

In contrast, the other options provided are associated with different types of radiation effects, such as neurological symptoms due to brain injuries, hematological effects related to the immune system, or dermal injuries leading to skin burns, which do not align with the specific manifestations of Gastrointestinal Syndrome.