Which of the following is classified as a critical organ affected by radiation?

The thyroid gland is classified as a critical organ affected by radiation due to its sensitivity to ionizing radiation and its vital role in the endocrine system. The thyroid absorbs iodine from the bloodstream to produce hormones, which regulate metabolism, growth, and development. When exposed to radiation, particularly from sources such as dental x-rays or radiation therapy, the thyroid tissue can be damaged, leading to potential health risks, including thyroid cancer and other disorders.

This sensitivity makes the thyroid a focal point in radiation protection measures, especially in dental practices where x-rays are commonly used. Dental professionals are trained to use protective measures, such as lead aprons and thyroid collars, to minimize radiation exposure to the thyroid during procedures. This underscores the importance of safeguarding this organ while performing necessary diagnostic procedures.