ANATOMY OFTHE PHARYNX AND THE ESOPHAGUS,MUSCLES, BLOOD SUPPLY AND INNERVATION.

1. PHARYNX &
ESOPHAGUS
Dr. Omar Mohd. Nouri Ibrahim
MBBS - Ibn Sena University

2. Intended Learning Outcomes
At the end of this session you will be able to:
1. Identify the location of the pharynx & esophagus.
2. Identify the pharynx & esophagus subdivisions, walls and muscles.
3. Recall the neurovascular supply and lymph drainage of the pharynx & esophagus.
4. Describe the deglutition process.
5. Discuss important clinical correlates related to the pharynx and esophagus.

3. Pharynx
01
Pharyngeal Muscles
02
Esophagus
03
Neurovascular
supply of the
pharynx
05
Esophagus
neurovascular supply
06
Clinical Correlations
07
Table of contents
04 Deglutition Summary
08

4. PHARYNX
● Funnel-shaped fibromuscular tube
● Extends from the base of the skull to the inferior border of the cricoid cartilage
● Conducts food to the esophagus and air to the larynx and lungs
● 12-14 cm long
● Divided into three parts:
○ Nasopharynx
○ Oropharynx
○ laryngopharynx

7. NASOPHARYNX
● Posterior to the nasal cavity
● Superior to the soft palate (C1)
● Has pharyngeal tonsils
(adenoids) and tubal tonsils.
● Connected with the tympanic
cavity through the auditory
(eustachian) tube
● Salpingopharyngeal fold
● Pharyngeal recess (the most
common site of nasopharyngeal
carcinoma)

8. OROPHARYNX
● Posterior to the mouth
● From lower surface of the soft
palate to the upper border of the
epiglottis (C3)
● Communicates with the mouth
through the oropharyngeal
isthmus
● Contains the palatine tonsils

9. LARYNGOPHARYNX
● Superior border of epiglottis to the
inferior border of the cricoid cartilage
(C6)
● Narrows and become continuous with
the esophagus
● Posterior and lateral walls are formed
by the palatopharyngeus and
stylopharyngeus muscles
● Communicates with the larynx through
the laryngeal inlet
● Contains the piriform fossa on each
side of the larynx inlet
● Separated from it by the ary-epiglotic
fold (medial boundary)

10. Clinical case
28 years old male presented
with pain in the neck of 5 days
in duration. Patient gave
history of severe choking
sensation while eating
chicken.

11. FOREGIN BODIES IN
LARYNGOPHARYNX
● May be lodged in the piriform fossa
● May pierce the mucus membrane and
injury the internal laryngeal nerve
○ Causes anesthesia of the
laryngeal mucous membrane as
far as the vocal folds

12. PHARYNGEAL WALL
The pharyngeal wall layers from anterior to posterior:
● Mucous membrane
● Submucosa
● Pharyngeal aponeurosis, pharyngobasilar fascia, ( fibrous layer lining the muscular layer)
● Muscular layer
● Buccopharyngeal fascia ( covers the outer surface of the muscular layer)
Pharyngeal wall is exceptional for the GIT
● Have a muscular layer composed of entirely skeletal muscles
● Longitudinal muscles layer (internal)
● Circular muscles layer (external)

13. PHARYNGEAL MUSCLES
➔ External circular layer of pharyngeal muscles consist of three pharyngeal
constrictors:
i. Superior
ii. Middle
iii. Inferior
◆ Inserts in median raphe of pharynx
◆ All supplied by the pharyngeal plexus
◆ Constrics walls of pharynx during swallowing
➔ Arranged in three layers overlapping each other
➔ Have strong internal facial lining called the pharyngobasilar fascia
➔ External thin fascial lining called the buccopharyngeal fascia
➔ Contract involuntary in a sequence from superior to inferior end of the pharynx,
propelling food into the esophagus

16. Internal Longitudinal
Muscles
1. Palatopharyngeus
2. Stylopharyngeus
3. Salpingopharyngeus
Elevate (shorten and widen) the
pharynx and larynx during
swallowing and speaking.
All supplied by pharyngeal plexus
except the stylopharyngeus by
the glossopharyngeal nerve.

17. ANY
QUESTIONS?

18. BLOOD SUPPLY OF THE PHARYNX
● Rich network of blood vessels with
extensive anastomosis
● Branches of external carotid artery supply
the whole pharynx
1. Ascending pharyngeal artery
2. Ascending palatine branch of facial artery
3. Tonsillar branch of facial artery
4. Dorsal lingual branch of lingual artery
5. Greater palatine artery
6. Pharyngeal branches of maxillary artery

19. Pharyngeal plexus of veins at
the posterior wall of
constrictor muscle drain into
● Facial vein
● Internal jugular vein
VENOUS DRAINAGE

20. ● Pharyngeal plexus supply all muscles
(motor) of the pharynx and soft palate
● Except the stylopharyngeus muscle is
supplied by the glossopharyngeal nerve
Motor supply by vagus via pharyngeal
branch.
● Inferior constrictor also receives some
motor fibers from the external and
recurrent laryngeal branches of vagus
Sensory fibers in the plexus are derived from
the glossopharyngeal nerve.
Nasopharynx receives sensory innervation
from the maxillary nerve.
PHARYNGEAL NERVES

21. DEGLUTITION
● Process that transfers a food bolus from the mouth through the pharynx and esophagus into
the stomach (swallowing).
● Occurs in three stages:
STAGE 1:
● Voluntary, mainly by movement of the tongue and soft palate
● Bolus is compressed against the palate and pushed from the mouth into the oropharynx
STAGE 2;
● Involuntary and rapid
● Soft palate is elevated, pharynx widens and shortens to receive bolus and larynx is elevated
STAGE 3:
● Involuntary; sequential contraction of the three pharyngeal constrictors creating peristalsis.

22. “FAILURE IS
SUCCESS IF WE
LEARN FROM IT”
-Malcolm Forbes

23. ESOPHAGUS
● Muscular tube, approximately 25 cm long
● Conveys food from the pharynx to the stomach
● Has internal circular and external longitudinal layers of muscles
● Begins at the level of C6 and terminates at the level of T11
● Terminates by entering the stomach at cardiac orifice of the stomach
● Consist of:
○ Striated (voluntary) muscle in its upper third
○ Smooth (involuntary in its lower third
○ Mixture of both in the middle third
● Food pass rapidly by peristalsis, aided by gravity but not dependent

24. ESOPHAGEAL CONSTRICTIONS
Normally has three constrictions:
➔ Cervical constriction (Upper esophageal sphincter ‘UES’)
◆ At pharyngo-esophageal junction
◆ Caused by cricopharyngeus muscle
➔ Thoracic (broncho-aortic) Constriction
◆ Crossed by the arch of the aorta first and then the left
main bronchus
➔ Diaphragmatic constriction
◆ Where it passes through the esophageal hiatus of the
diaphragm
◆ The hiatus is in the right crus of the diaphragm
➔ Awareness of these constrictions is important when passing
instruments to the stomach through the esophagus.

25. CERVICAL ESOPHAGUS
● Voluntary, begins at the level of C6
● Pharyengo-esopageal junction appears as a constriction produced by cricopharyngeus muscle
○ It is the narrowest part of the esophagus
● Tracheo-esophageal groove is between the trachea and esophagus
○ Recurrent laryngeal nerve lie in or near the groove
● Relations: Thyroid gland lobes and carotid sheath and its contents
● Blood supply: Branches of inferior thyroid arteries
● Lymphatics: Paratracheal and inferior deep cervical lymph nodes
● Innervation:
○ Somatic branches via the recurrent laryngeal nerves
○ Vasomotor branches from the cervical sympathetic trunks

27. THORACIC ESOPHAGUS
● Enters superior mediastinum between trachea and
vertebral column
● Relations:
○ Thoracic duct and arch of aorta (left side),
azygos vein (right side)
● Blood supply:
○ Bronchial branches from descending aorta,
drains into azygos vein
● Lymphatics:
○ Superior and posterior mediastinal nodes
● Innervation:
○ Esophageal plexus

28. ABDOMINAL ESOPHAGUS
● Attached to margins of the esophageal hiatus in the diaphragm by the phrenico-esophageal ligament
● Covered by peritoneum
● Blood supply:
○ Left gastric artery (branch of celiac trunk)
○ Submucosal veins drain in left gastric vein drains into portal venous system
○ Esophageal veins drain into the azygos into the systemic venous system
● Lymphatics:
○ Left gastric lymph nodes into celiac nodes
● Innervation:
○ Esophageal plexus
○ Formed by:
■ Vagal trunks
■ Thoracic sympathetic trunks via greater splanchnic nerves

32. ESOPHAGUS
ABNORMALITIES?

33. TRACHEO-ESOPHAGEAL FISTULA
● Most common birth defect of the
esophagus
● Usually combined with esophageal
atresia
● 90% of TEF cases:
○ Superior part of esophagus end in
a blind pouch
○ Inferior part communicates with
the trachea

34. ACHALASIA
● Due to the loss of ganglion cells in the
myenteric (auerbach) plexus
● Characterized by failure to relax the LES
leading to difficulty in passage of food
and progressive dysphagia
● Barium swallow - X Ray
○ Rat-tail appearance

35. ESOPHAGEAL CANCER
● Most common presentation is dysphagia
● Recognized until the lumen is reduced by
30-50%
● Diagnosed by barium swallow and
endoscopy

36. PYROSIS
● Means burning = heartburn
● Due to regurgitation of gastric content
● Known as GERD
● Causes:
○ Hiatal hernia
○ Obesity
○ smoking

39. ESOPHAGEAL VARICES
● Submucosal veins of inferior esophagus drain into both the portal and systemic venous system
● In portal hypertension there is increased pressure in portal veins
● Blood is unable to pass through the liver via hepatic portal vein causing reversal of venous blood
● Submucosal veins enlarges forming varices (distended collateral channels
● These varices may rupture and cause severe life threatening hemorrhage
● Symptom: haematemesis
● Causes:
○ Liver cirrhosis
○ schistosomiasis

40. SUMMARY
ESOPHAGUS
MUSCLES
PHARYNX
Nasopharynx
Oropharynx
Laryngopharynx
PHARYNX
NEUROVASCULAR
Circular and longitudinal
PHARYNGEAL
MUSCLES
ESOPHAGUS
Cervical
Thoracic
abdominal
ESOPHAGUS
NEUROVASCULAR

41. REFERENCES
1. Keith L. Moore, Moore Clinically Oriented Anatomy, 7th
edition, 2014.
2. Lawrence E. Wineski, Snell Clinical Anatomy by Regions,
10th edition.
3. Chummy S. Sinnatamby, Last’s Anatomy, 11th edition
4. Kyung Won Chung, BRS Gross Anatomy, 9th edition.

42. Do you have any questions?
Thanks