00:01
I introduced Waldeyer's Ring
earlier on in this presentation
and said that this was
a circumpharyngeal ring
of lymphoid tissue
that surrounded and
protected the openings
of the aerodigestive tract
from the external
environment.
00:18
The lymphoid tissues
that make up this ring
have already been mentioned
throughout this lecture,
but I would like to
remind you once again,
so Waldyer's Ring
is made up of:
The nasal pharyngeal tonsil,
which lies at the
junction the rough
and posterior wall
the nasopharynx.
00:37
The tubal tonsils,
which lie near the openings
of the Eustachian tube
in the lateral wall
of the nasopharynx.
00:46
The Palatine tonsils which lie in the
tonsillar fossa of the oral pharynx,
again in between the anterior
and posterior pillars,
and the lingual tonsils,
which lie near the
base of the tongue.