The Tonsils and Adenoids.
The openings to the pharynx from the nose and mouth are protected by a ring of
tonsils and other types of lymphoid tissue (=Waldeyer's ring). Inhaled and consumed
pathogens drain into these masses, where they are destroyed by lymphocytes and
other types of leukocytes (white blood cells).
Embedded in the posterior wall of the nasopharynx, near the midline, is the pharyngeal
tonsil (= adenoids). An inflam-mation of the pharyngeal tonsils may result in
the partial blockage of the nasopharynx, causing breathing difficulties and an
alteration of the voice (increased nasal tones).
Along the anterolateral walls of the oropharynx are the palatine tonsils, which
are often referred to as "the tonsils". Viral and bacterial infections often
cause the these masses to become inflamed and sore, a condition referred to as
tonsilitis.
Guarding the base of the tongue is the lingual tonsil.
