Tonsil

The tonsils are areas of lymphoid tissue on either side of the throat. As with other organs of the lymphatic system, they act as part of the immune system to help protect against infection. In particular, the tonsils are believed to be involved in helping fight off pharyngeal and respiratory tract infections.

Infection of the tonsils, called tonsillitis, causes sore throat and fever. In chronic cases, or in acute cases where the tonsils become so swollen that swallowing is impaired, a tonsillectomy can be performed to remove the tonsils. Patients whose tonsils have been removed are still protected from infection by the rest of their immune system.

When bacteria that collect on the tonsils consume mucus that has pooled in pits in the tonsils a whitish-yellow deposit is produced. These deposits are known as tonsiloliths or "tonsil stones" and emit a very pungent odour due to the presence of volatile sulphur compounds.