anatomy of tonsil and oropharynx in simple words and easy to understand format.

1. ANATOMY OF TONSIL
AND OROPHARYNX
T. Aruvi
III Year MBBS
SAVEETHA MEDICAL COLLEGE

2. OROPHARYNGEAL ANATOMY

3. Oropharynx - location
• The oropharynx extends from below the soft
palate to the upper border of the epiglottis.
• It opens into the mouth through the
oropharyngeal isthmus, demarcated by the
palatoglossal arch, and faces the pharyngeal
aspect of the tongue.
• Its lateral wall consists of the palatopharyngeal
arch and palatine tonsil.
• Posteriorly, it is level with the bodies of the
second, and upper part of the third, cervical
vertebrae

5. Soft palate
• The soft palate is a mobile flap suspended
from the posterior border of the hard palate,
sloping down and back between the oral and
nasal parts of the pharynx.
• The soft palate is a thick fold of mucosa
enclosing an aponeurosis, muscular tissue,
vessels, nerves, lymphoid tissue and mucous
glands.
• A thin, fibrous, palatine aponeurosis composed
of the expanded tendons of the tensor veli
palatini muscles strengthens the soft palate

7. Palatoglossal and
palatopharyngeal arches
• The lateral wall of the oropharynx presents two prominent
folds, the palatoglossal and palatopharyngeal folds.
• The palatoglossal arch, the anterior fold, runs from the
soft palate to the side of the tongue and contains
palatoglossus.
• The palatopharyngeal arch, the posterior fold, projects
more medially and passes from the soft palate to merge
with the lateral wall of the pharynx; it contains
palatopharyngeus.
• A triangular tonsillar fossa (tonsillar sinus), lies on each
side of the oropharynx between the diverging
palatopharyngeal and palatoglossal arches, and contains
the palatine tonsil.

8. Vascular supply
• The arterial supply of the soft palate is usually
derived from the ascending palatine branch of
the facial artery.
• Sometimes this is replaced or supplemented by
a branch of the ascending pharyngeal artery
which descends forwards between the superior
border of the superior constrictor and levator
veli palatini, and accompanies the latter to
the soft palate.
• The veins of the soft palate usually drain to
the pterygoid venous plexus.

9. Innervation
• General sensation from most of the soft palate is
carried by branches of the lesser palatine nerve
and from the posterior part of the palate by
pharyngeal branches from the glossopharyngeal
nerve and from the plexus around the tonsil.
• The lesser palatine nerve also carries the
secretomotor supply to most of the mucosa of the
soft palate.
• Postganglionic sympathetic fibres run from the
carotid plexus along arterial branches supplying
the palate.

13. Tonsils
• Paired palatine tonsils
• Nasopharyngeal or adenoid
tonsil
• Paired tubal tonsil
• Lingual tonsil
• Together these comprise the Waldeyer’s ring

14. Palatine tonsil
• Palatine tonsils, occasionally called the
faucial tonsils,are the tonsils on the left and
right sides at the back of the throat which can
often be seen as white lumps.
• The palatine tonsil is one of the mucosa-associated
lymphoid tissues (MALT), located at
the entrance to the upper respiratory and
gastrointestinal tracts to protect the body
from the entry of exogenous material through
mucosal sites.

15. Location – Isthmus faucium
• The fauces are regarded as the two pillars,
formed by the palatoglossus and the
palatopharyngeus muscle and covered with
mucous membrane.
• The anterior one is known as the palatoglossal
arch, and the posterior one is known as the
palatopharyngeal arch.
• Between these two arches is the palatine
tonsil.

16. Isthmus Faucium

17. Blood supply
• Blood supply is provided by tonsillar branches of five
arteries:
• the dorsal lingual artery (of the lingual artery)
• ascending palatine artery (of the facial artery)
• tonsillar branch (of the facial artery)
• ascending pharyngeal artery (of the external carotid
artery)
• the lesser palatine artery (of the descending palatine
artery).
• The tonsils venous drainage is by the peritonsillar
plexus, which drain into the lingual and pharyngeal
veins, which in turn drain into the internal jugular
vein.

19. Nerve supply
• The palatine tonsils receive afferent nervous
innervation via the tonsillar plexus, which has
contributions from the trigeminal nerve via the
lesser palatine nerves, and the glossopharyngeal
nerve (CN ix).
• The glossopharyngeal nerve continues past the
palatine tonsil and innervates the tongue to
provide general and taste sensation.
• This nerve is most likely to be damaged during a
tonsillectomy, which leads to reduced or lost
general sensation and taste sensation to the
posterior third of the tongue.

20. Adenoid tonsils
• The adenoid, also known as a
pharyngeal tonsil or
nasopharyngeal tonsil, is
situated posterior to the nasal
cavity, in the roof of the
nasopharynx.
• Normally, in children, it forms
a soft mound in the roof and
posterior wall of the
nasopharynx, just above and
behind the uvula.

21. Tubal tonsil
• The tubal tonsil is one of the four main tonsil
groups comprising Waldeyer's tonsillar ring.
• The tubal tonsil is very close to the torus
tubarius.
• It is located posterior to the opening of the
Eustachian tube into the nasopharynx.

22. Lingual tonsil
• The lingual tonsils are
rounded masses that cover
the posterior region of the tongue.
• They are located on the dorsal
surface at the base of the tongue.
• They are partially surrounded by
connective tissue placing them in the
group of Partially Encapsulated
Lymphatic Organs, tonsils.
• They have associated mucous glands
which are drained by ducts directly into
the single tonsillar crypt.

23. Histology
• Tonsils are large non-encapsulated (or partially
encapsulated) masses of lymphoid tissue.
• The luminal surface of the tonsils are covered
with a stratified squamous epithelium.
• The tonsils have many invaginations which
form blind crypts.
• Below the epithelium, there are many
lymphoid follicles beneath which have
germinal centres like the lymph nodes.