Anatomy of the pharynx

Prepared by DR . AMER SALEEM

M.B.Ch.B -F.I.B.M.S(ENT)
TUCOM
 Nasal Cavity

Pharynx
o Muscular tube lying behind the nose, oral cavity & larynx.
o Extends from the base of the skull to level of the Oral Cavity

C6 vertebra, where it continuous with the esophagus .

o The anterior wall is deficient and shows (from above to downward)
1 Posterior nasal apertures. Larynx
2 Opening of the oral cavity.
3 Laryngeal inlet.
o The muscles are arranged in circular and longitudinal layers.

Extra
Muscles that form the walls of the Pharynx :
A-Circular Constrictor Muscles :
Three in number:
(1) Superior constrictor S
(2) Middle constrictor
(3) Inferior constrictor M
The three muscles overlap each other.
I
Functions: Extra
- Propel the bolus of food down into the esophagus.
by contracting sequentially from superior to inferior to constrict
the lumen
: constrictor (Cricopharyngeus) act
- lower fibers of the inferior
as a sphincter, preventing the entry of air into the esophagus
between the acts of swallowing.

Extra
B-Longitudinal Muscles

Three in number:
(1) Stylopharyngeus
(2) Salpingopharyngeus
3 Palatopharyngeus

Function:
- Elevate the larynx & pharynx during swallowing
 Pharynx
The pharynx is divided into three parts: note: Nasopharynx & laryngopharynx are concerned with
respiration Oropharynx & laryngopharynx are concerned with
o Nasopharynx. swallowing
o Oropharynx.
o Laryngopharynx.

Divisions of pharynx
 Pharynx
Nasopharynx
o Extends from the base of skull to the soft palate.
o Communicates with the nasal cavity through posterior nasal
apertures (choanae)
o Pharyngeal tonsils (Adenoides ) present in the submucosa
covering the roof.
o Lateral wall shows:
1. Opening of auditory tube
2. Tubal elevation produced by posterior margin of the auditory
tube.
3. Tubal tonsil.
4.Pharyngeal recess
5.Salpingopharyngeal fold
(raised by salpingo-pharyngeus muscle)
🞇 The lymphoid tissue of the nasopharynx and
oropharynx is composed of the adenoids, the tubal
tonsils, the lateral bands, the palatine tonsils, and the
lingual tonsils.
🞇 There are also lymphoid collections in the posterior
pharyngeal wall and in the laryngeal ventricles.
🞇 These structures form a ring of tissue named
Waldeyer’s ring after the German anatomist who
described them.

🞇 It is a single mass of pyramidal tissue with its base on

the posterior nasopharyngeal wall and it’s apex pointed
toward the nasal septum.
🞇 The surface is invaginated in a series of folds.
🞇 The epithelium is pseudostratified ciliated epithelium
and is infiltrated by the lymphoid follicles.
Waldeyer’s ring
Blood supply is from
the:
🞇 Ascending palatine branch of the facial artery
🞇 Pharyngeal branch of the internal maxillary artery
🞇 Artery of the pterygoid canal
🞇 Ascending cervical branch of the thyrocervical trunk.

🞇 Venous drainage is through the pharyngeal plexus

and the pterygoid plexus flowing ultimately into the facial
and internal jugular veins.
🞇 Innervation is derived from the glossopharyngeal and
vagus nerves.
🞇 Efferent lymphatics drain to the retropharyngeal nodes
and the upper deep cervical nodes.
Pharynx
Oropharynx
o Lies behind the mouth cavity, communicates with the
oral cavity through the oropharyngeal isthmus*
o Extends from soft palate to upper border of epiglottis.
o Lateral wall shows:
o Palatopharyngeal fold or arch.
o Palatoglossal fold (glossal=related to tongue)
o Palatine tonsil ‫ا‬located between them in a
depression called the ‘tonsillar fossa’.

Palatoglossal fold
Extra Extra
Palato-pharyngeal fold Tonsillar fossa
Pharynx
Palatine Tonsil
o Two masses
o Formed of lymphoid tissue
o located in the lateral wall of the oropharynx in the tonsillar fossa,
Each one is covered by:
o mucous membrane
o laterally by fibrous tissue (capsule)It reaches the maximum size
during childhood, after puberty it diminishes in size
Pharynx
Palatine Tonsil
Arterial supply:
tonsillar artery from the fascial artery , lingual artery,
ascending pharyngeal artery and greater palatine artery.

Venous drainage:
join external palatine vein, pharyngeal vein, and fascial vein

Lymphatic drainage:
to the upper deep cervical (jugulodigastric node)
Pharynx
Palatine Tonsil

Relations
Anteriorly palatoglossal arch

Posteriorly palatopharyngeal arch

Superiorly soft palate

Inferiorly posterior 1\3 of the tongue

Medially cavity of the oropharynx

Extra
Laterally (1) superior constrictor of the pharynx
separated from it by loose connective
tissue through which descends the (2)
external palatine vein, (3) loop of the
facial artery and , (4) the internal
carotid artery which lies behind and
lateral to the tonsils.
Extra
 Pharynx
Laryngopharynx
o Lies behind the laryngeal inlet & the posterior surface of
larynx.
o communicates with the larynx through the laryngeal inlet
o Extends from upper border of epiglottis to lower border of
cricoid cartilage.

o A small depression situated on either side of the laryngeal

inlet is called ‘Piriform Fossa’ it is a common site
for the lodging of foreign bodies.

o Branches of internal laryngeal & recurrent laryngeal nerves

lie deep to the mucous membrane of the fossa‘Piriform
Fossa’ and are vulnerable to injury during removal of a
foreign body.

Extra
Pharynx
Nasopharynx: Maxillary nerve
Sensory Oropharynx: Glossopharyngeal nerve (cranial nerve number 9)
Nerve Laryngopharynx: Vagus nerve (cranial nerve number 10 )
Supply
All the muscles of pharynx are supplied by the pharyngeal plexus.
Motor
Except the Stylopharyngeus is supplied by the glossopharyngeal nerve

from branches of the following arteries:

Arterial supply 1. Ascending pharyngeal 2 .Ascending palatine 3. Facial
4. Maxillary 5. Lingual

drain into pharyngeal venous plexus, which drains into the internal
Veins
jugular vein

drain into the deep cervical lymph nodes either directly, or indirectly via
Lymphatics the retropharyngeal or paratracheal lymph nodes
 Summary
Begins Ends Communicates with Tonsil Structures
Nasopharynx Base of skull Soft palate Nasal cavity Pharyngeal Opening of auditory
Through posterior nasal Tubal tube
apertures Tubal elevation
Pharyngeal recess
Salpingopharyngeal
fold

Oropharynx Soft palate Upper border of Oral cavity Palatine Palatopharyngeal fold
epiglottis Through oropharyngeal Palatoglossal fold
isthmus

Laryngopharynx Upper border of Lower border of Larynx - Piriform Fossa

epiglottis cricoid cartilage Through laryngeal inlet