Tonsils

• Is found in the posterior wall and roof of the nasopharynx and is called an adenoid when enlarged.

• Lies on each side of the oropharynx in an interval between the palatoglossal and palatopharyngeal folds.
• Receives blood from the ascending palatine and tonsillar branches of the facial artery, the descending palatine branch of the maxillary artery, a palatine branch of the ascending pharyngeal artery, and the dorsal lingual branches of the lingual artery.
• Is innervated by branches of the glossopharyngeal nerve and the lesser palatine branch of the maxillary nerve.

• Is a collection of lymphoid nodules near the pharyngeal opening of the auditory tube.

• Is a collection of lymphoid follicles on the posterior portion of the dorsum of the tongue.

• Is a tonsillar ring of lymphoid tissue at the oropharyngeal isthmus, formed by the lingual, palatine (faucial), tubal (eustachian), and pharyngeal tonsil.