Trachea into left and right main bronchi. The trachea begins level with the sixth cervical vertebra and the carina is found at the level of the fifth thoracic vertebra (T5), opposite the sternal angle and can be positioned up to two vertebrae lower or higher, depending on breathing. The trachea is surrounded by rings of hyaline cartilage; these rings are incomplete and C-shaped. The cricoid cartilage is attached to the first tracheal ring at top of the trachea and acts as the bottom of the larynx. There are fifteen to twenty rings in total, separated by narrow intervals. These reinforce the
Unethical human experimentation in the United States ashes analyzed for radioisotopes. This project was kept secret primarily because it would be a public relations disaster; as a result parents and family were not told what was being done with the body parts of their relatives. Between 1960 and 1971, the Department of Defense funded non-consensual whole body radiation experiments on mostly poor and black cancer patients, who were not told what was being done to them. Patients were told that they were receiving a "treatment" that might cure their cancer, but the Pentagon was trying to determine the effects of high levels of radiation on the human