1. Anatomy of Oral Cavity, Pharynx & Oesophagus
Dr. Vishal Sharma

2. Oral Cavity

3. Parts of Oral Cavity

4. Floor of mouth

5. Lymphatic drainage

6. Intrinsic tongue muscles

7. Extrinsic tongue muscles

8. Coronal section of tongue

9. Actions of tongue muscles
Inferior Longitudinal: moves tip up & down
Superior Longitudinal: moves tip up & down
Transverse: narrows & lengthens tongue
Vertical: flattens & depresses tongue
Genioglossus: Prevents tongue from falling back
Styloglossus: Pulls tongue up & back
Palatoglossus: Pulls tongue back
Hyoglossus: Depresses tongue

10. Nerve Supply of Tongue Anterior 2/3 Posterior 1/3 Sensory Lingual
Glossopharyngeal
Motor
Hypoglossal ***
Taste
Chorda tympani
*** except palatoglossus which is supplied by pharyngeal plexus

11. Nerve
Supply of
Tongue

12. Papillae in tongue

13. Papillae in tongue
Lingual taste buds sit on lateral borders of raised papillae. They are classified as:
Fungiform: at tip & sides of tongue
Circumvallate: just in front of terminal sulcus
Foliate: at posterior lateral margins of tongue
Filiform: centre of tongue, have no taste buds

14. Papillae in tongue

15. Tongue Map ? Sweet = Sucrose Salty = NaCl Sour = HCl Bitter = Quinine
Umami = Glutamate

16. Taste Bud

17. Taste Pathway

18. Pharynx

19. Divisions

20. Divisions

21. Lower Limit of Nasopharynx
Lower border of soft palate or Junction b/w hard & soft palate
Oropharynx
Tip of epiglottis or Body of hyoid bone or Base of vallecula
Hypopharynx
Lower border of cricoid or
Lower border of C6 vertebra

22. Anterior Relations

23. Nasopharynx

24. Nasopharyngeal isthmus

25. Nasopharyngeal Isthmus
Separates nasopharynx from oropharynx
Bounded anteriorly by soft palate & posteriorly
by mucosal ridge on nasopharyngeal wall called
Passavant’s ridge (due to palatopharyngeus)
Closure of this isthmus prevents nasal
regurgitation & nasal intonation

26. Parts of Oropharynx

27. Parts of Oropharynx

28. Oropharyngeal Isthmus

29. Oropharyngeal Isthmus
Separates oral cavity from oropharynx
Boundaries are:
Superior: Junction between hard & soft palate
Inferior: Circumvallate papillae
Lateral: Anterior tonsillar pillars (palatoglossus)

30. Waldeyer’s Tonsillar Ring

31. Waldeyer's tonsillar ring
Vertically oriented, sub-epithelial lymphoid tissue ring located in pharynx, thought to function as a barrier to infection in first few years of life. Named after nineteenth century German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz.

32. Parts of Hypopharynx

33. Coronal section of Pharynx

34. Layers of Pharyngeal Wall
Mucosa: ciliated columnar in nasopharynx & stratified squamous elsewhere
Pharyngo-basilar fascia
Longitudinal muscles: stylo-pharyngeus salpingo-pharyngeus + palato-pharyngeus
Constrictor muscles: superior + middle + inferior
Bucco-pharyngeal fascia

35. Muscles

36. Structures Passing
Between Skull Base & Superior Constrictor (Sinus of Morgagni)
Eustachian tube + Levator palatini + Tensor palatini + Ascending palatine artery
Between Superior & Middle Constrictors
Glossopharyngeal nerve & Stylopharyngeus muscle
Between Middle & Inferior Constrictors
Internal Laryngeal nerve & Superior Laryngeal artery
Below Inferior Constrictor
Recurrent Laryngeal nerve & Inferior Laryngeal artery

37. Nerve Supply Nasopharynx: pterygo-palatine ganglion (V2)
Oropharynx: glossopharyngeal & vagus nv
Hypopharynx: Superior & recurrent laryngeal nv
All muscles by pharyngeal nerve plexus (vagus nv carrying cranial part of accessory nv) except stylopharyngeus (glossopharyngeal nv) & cricopharyngeus (also by recurrent laryngeal)

38. Arterial Supply Facial artery Lingual artery
Ascending pharyngeal artery
Ascending palatine artery
Greater palatine artery
Artery of pterygoid canal
Superior laryngeal artery

39. Venous Drainage Upper pharynx:
Pharyngeal venous plexus situated on middle constrictor  pterygoid venous plexus & internal jugular vein
Lower pharynx:
Inferior thyroid veins

40. Lymphatic Drainage Nasopharynx: upper deep cervical + retro-
pharyngeal + parapharyngeal +
posterior triangle
Oropharynx: upper deep cervical + retro-
pharyngeal + parapharyngeal
Hypopharynx: deep cervical + parapharyngeal +
paratracheal + supraclavicular

41. Killian’s Dehiscence

43. Killian’s Dehiscence
Triangular weak area between thyropharyngeus & cricopharyngeus part of inferior constrictor
Mucosa herniates through it to form hypo-pharyngeal pouch (Zenker’s diverticulum)
Perforation occurs here during forceful oesophagoscopy (gateway of tears)

44. Oesophagus

45. Introduction Also called gullet 23 to 25 cm long
Extends from crico-pharyngeal sphincter (C6 vertebra) to cardiac orifice of stomach (T11 vertebra)

46. Anterior Curvature Follows antero- posterior curve of vertebral column
through neck, thorax
(postr mediastinum)
& upper abdomen

47. Lateral curvatures
Starts in midline → deviates to left at C7 → returns to midline at T5 → deviates to left again at T7 to reach gastric cardia

48. Natural Constrictions

50. Natural Constrictions
Site
Vertebral Level
Distance from central incisor
Cricopharynx
C 6
15 cm
Aortic arch
T 4
25 cm
Lt main bronchus
T 5
28 cm
Oesophageal hiatus
T 10
40 cm

51. Importance of constrictions
Common sites for lodgement of oesophageal foreign bodies
Common sites for caustic stricture of oesophagus

52. Descending thoracic aorta, Left gastric, Inferior phrenic
Blood Supply
Part
Arterial
Venous
Cervical
Inferior thyroid
Thoracic
Descending thoracic aorta,
Bronchial
Azygos,
Hemi-azygos
Abdominal
Left gastric, Inferior phrenic
Left gastric,
Abdominal azygos

55. Oesophageal varices Left gastric vein is a site of portal-systemic
anastomosis. Portal
obstruction leads to
varicose veins in
lower oesophagus

56. Nerve Supply
Cervical: recurrent laryngeal nerve & cervical sympathetic trunk
Thoracic: vagal trunks, oesophageal plexus & thoracic sympathetic trunk
Abdominal: vagal trunks & thoracic sympathetic trunk
Esophageal pain mimics cardiac angina due to common nerve supply

58. Lymphatic Drainage
deep cervical + posterior mediastinal + left gastric lymph nodes
drain into coeliac lymph nodes
thoracic duct

60. Histology

61. Histology
Four coats from outside inwards: 1. Fibrous coat (adventitia) 2. Muscular coat (muscularis propria)
3. Submucous coat
4. Mucous coat

62. Detailed Histology

63. Mucous coat 1. Epithelium: non-keratinizing stratified sqamous
2. Lamina propria: loose areolar tissue with
lymphoid aggregates
3. Muscularis mucosae: produces local
movement of mucosa & helps in
drainage of gland secretions

64. Mucous coat Pink, smooth, protective oesophageal mucosa
leads to red, mamillated,
secretory gastric mucosa
across Z (zigzag) line at
38-40 cm from incisors.
Higher Z line seen in
Barret’s esophagus.

65. Z line in endoscopy

66. Barret’s esophagus

67. Submucous coat Loose supporting areolar tissue contains:
Seromucous glands
Blood vessels
Lymphatic channels
Parasympathetic ganglia forming Meissner's nerve plexus

68. Muscularis propria External longitudinal muscle
Internal circular muscle
Parasympathetic ganglia forming Auerbach's nerve plexus lies b/w them
Upper 1/3: striated muscle
Middle 1/3: striated & smooth
Lower 1/3: smooth muscle

70. Fibrous coat (adventitia)
Layer of loose, supportive fibrous tissue
Conducts major vessels & nerves longitudinally
A serosa formed by visceral peritoneum replaces adventitia of intra-abdominal segment of oesophagus

71. Thank You