Trachea the larynx and then the pharynx where it can be either swallowed into the stomach or expelled as phlegm. This self-clearing mechanism is termed mucociliary clearance. Inflammation of the trachea is known as tracheitis. When the trachea is inflamed as well as the larynx and bronchi, this is known as croup, which often causes a distinct, barking cough. Tracheal intubation refers to the insertion of a catheter down the trachea. This procedure is commonly performed during surgery, in order to ensure a person receives enough oxygen when sedated. The catheter is connected to a machine that monitors the airflow, oxygenation
Traditional Chinese medicines derived from the human body were successfully making quasi-empirical preparations of active substances with androgens and estrogens, a technique that modern biochemists did not develop until the early 20th century. The physician William C. Cooper and the sinologist Nathan Sivin (1973) chose what the Chinese call "rényào" 人藥 "human drugs" as a pilot experiment sample for pharmacologically analyzing the efficacy of drugs used in TCM. In contrast to many traditional Chinese plant, animal, and mineral pharmaceuticals with uncertain active constituents, the chemical composition of the human body and parts is well known, and "their therapeutic effectiveness, or lack of it, can be objectively, if approximately,