Anatomy of Pharynx & Larynx

1. Pharynx & Larynx
By
Dr Nassar
Ayoub

2. • Pharynx
– Subdivisions and borders
– Pharyngeal muscles
– Blood supply and innervation
• Larynx
– Laryngeal cartilages Paired vs.
unpaired Basic structure
Membranes and ligaments
– Vocal cords and folds
– Muscles and innervation
– Blood supply

4. • Is a wide muscular tube
• 12 cm in length
• Located posterior to the nasal and oral
cavities
• Extends inferiorly, posterior to the larynx
• Extends from the cranial base to the
inferior border of the cricoid cartilage
(anteriorly) and inferior border of C6
(posteriorly) [Extends from the base of the
skull to the level of the C6 vertebra] where
it is continuous with the oesophagus
• Widest opposite the hyoid bone and
narrowest at the junction where it joins the
oesophagus

5. Pharyngeal wall
The wall of the Pharynx consists of five
layers:
1.Mucous membrane
2.Submucosa
3.Pharyngobasilar fascia
4.Pharyngeal muscles (3 constrictors)
a- Stylopharyngeus
b- Salpingopharyngeus
C- Palatopharyngeus
5.Buccopharyngeal fascia

7. • Nasopharynx
• Oropharynx
• Laryngopharynx

8. • Respiratory function
• Roof and Posterior wall:
Continuous surface that lies
inferior to the body of the
sphenoid bone and the
basilar part of the occipital
bone
• Pharyngeal tonsils:
Found in the mucous membrane
of the roof and the posterior
wall of the nasopharynx

10. • Digestive function
• Helps in the process of
deglutition
• Borders
Superiorly: Soft Palate
Inferiorly: Base of the Tongue
Laterally: Palatoglossal and
Palatopharyngeal arches and
palatine tonsils

11. • Palatine tonsils
– Collections of lymphoid tissue on
either side of the Oropharynx
between the arches
• Tonsillar bed
– Superior constrictor of the
pharynx and the pharyngobasilar
fascia form the tonsillar bed

12. ARTERIAL SUPPLY OF THE
TONSIL
1- Tonsillar A. From facial A.
2- Lingual A.
3- Ascending palatine A.
4- Maxillary artery.
Acute follicular tonsillitis

13. • Extends from the superior
border of the epiglottis and
the pharyngoepiglottic folds to
the inferior border of the
cricoid cartilage
Borders
• Posteriorly: related to the
bodies of the C4- C6
vertebrae.
• Posterior and lateral walls:
Middle and Inferior constrictor
muscles

14. • Palatopharyngeus and
Stylopharyngeus muscles form the
walls
• Piriform recess, small depression of
the laryngopharyngeal cavity on
either side of the laryngeal inlet
• Separated from the laryngeal inlet
by the aryepiglottic fold

15. 2 layers of voluntary
muscle:
• External circular layer
• Internal Longitudinal layer

16. External circular layer
•Constrictor muscles
•Primarily responsible
for constricting the
pharynx during
swallowing
Both types are
innervated by
the vagus nerve,
except for
the stylopharyngeus,
which is innervated by
the glossopharyngea
l nerve.

17. • Internal Longitudinal layer
• Elevate/shorten and widen the
pharynx during swallowing and
speaking
• Palatopharyngeus
• Stylopharyngeus
• Salpingopharyngeus
Palatopharyngeus and
salpingopharyngeus are innervated by
the pharyngeal branch of CNX and
the pharyngeal plexus
• Stylopharyngeus is innervated by CN
IX

18. Sensory: Each of the three sections of the pharynx have a
different innervation:
The nasopharynx is innervated by the maxillary nerve (CN
V2).
The oropharynx by the glossopharyngeal nerve (CN IX).
The laryngopharynx by the vagus nerve (CN X).
Motor: All the muscles of the pharynx are innervated by the
vagus nerve (CN X), except for the stylopharyngeus, which is
innervated by the glossopharyngeal nerve (CN IX).

19. Blood Supply of the
pharynx:
Arterial supply is via
branches of the external
carotid artery:
• Ascending pharyngeal artery
• Ascending palatine artery
• Tonsillar branches of the facial
artery
• Branches of the maxillary and
lingual arteries
• Pharyngeal branches of the
inferior thyroid artery
Venous drainage is achieved by
the pharyngeal venous plexus,
which drains into the internal jugular
vein.

21. Clinical Relevance: Pharyngeal Diverticulum (Pouch)
Inferior pharyngeal constrictor is found in the laryngopharynx and has two
components. The superior component (cartilage and the inferior component
(cricopharyngeus) has horizontal fibres that attach to the cricoid cartilage
This area between the two is a weak area in the muscosa.
Normally during swallowing, the thryopharyngeus contracts as the
cricopharyngeus relaxes, allowing the bolus of food to be propelled into the
oesophagus and preventing the intrapharyngeal pressure form rising.
If this coordinated relaxation of the cricopharyngeus does not occur,
the intrapharyngeal pressure tends to rise and pharyngeal mucosa forms
a midline diverticulum in the area between the thyropharyngeus and
cricopharyngeus.
It is possible for food to accumulate here, leading to dysphagia.

22. Barium swallow X-ray

23. Nasopharyngeal tonsil
• Adenoids is the
hypertrophied mass of
lymphoid tissue situated at
the junction of roof & post.
wall of nasopharynx.
• The mass of lymphoid
tissue is termed as Adenoids
only when it is hypertrophied.
• It usually undergoes
atrophy by puberty (13- 14
yrs)

24. Waldeyer’sRing
• Waldeyer's
tonsillar ring
includes
1. Adenoid tonsil
2. Two tubal
tonsils
3. Two palatine
tonsils
4. Lingual tonsil.

25. LARYNX
• Is the upper ,
expanded part of
the windpipe
which is modified
for phonation
• Supported by a
number of
cartilages

27. • Complex organ of voice
production
• Composed of 9 cartilages
connected by membranes
and ligaments
• Contains the vocal folds
• Located anteriorly in the
neck
• Vertebral levels C3-C6
• Connects the inferior part of
the Oropharynx to the
trachea
• Lies anterior to the
Laryngopharnx
• Secondary function is to
guard the air passages

34. • Main divisions of the
Laryngeal Cavity
1- Laryngeal Vestibule
2- Laryngeal cavity
3- Infraglottic cavity

41. Muscle Origin Insertion Innervation Action
Cricothyroid Antero-lateral part
of cricoid cartilage
Inferior margin and
inferior horn of thyroid
cartilage
External
laryngeal nerve
Stretches and tenses
vocal ligament
Thyro-arytenoid Lower ½ of
posterior aspect of
angle of thyroid
laminae and
cricothyroid
ligament
Anterolateral arytenoid
surface
Inferior
laryngeal nerve
(terminal part of
recurrent
laryngeal nerve
from vagus)
Relaxes valocal
ligament
Posterior Crico-
arytenoid
Posterior surface
of lamina of cricoid
cartilage
Vocal process of
arytenoid cartilage
Abducts vocal folds
Lateral crico-
arytenoid
Arch of arytenoid
cartilage
Adducts vocal folds
Transverse &
Oblique arytenoids
One arytenoid
cartilage
Contra-lateral arytenoid
cartilage
Adducts arytenoid
cartilages
Vocalis Lateral surface of
vocal process of
arytenoid
cartilages
Ipsilateral vocal ligament Relaxes posterior vocal
ligament while
maintaining tension of
anterior part

42. • Superior Laryngeal artery
Supplies the internal surface of the larynx
• Cricothyroid artery
Supplies the cricothyroid muscle
• Inferior Laryngeal artery
Supplies the mucous membrane and the muscles of the inferior part of the
larynx