1. 10. Morphology and histology of the oral cavity, soft palate and the faucial isthmus
soon: morphology and histology of the tongue and the salivary glands
4th semester: morphology and histology of the teeth
Mark Kozsurek, M.D., Ph.D.
ED I., 22/02/2017

2. Oral cavity extends from the oral fissure to the oropharyngeal isthmus and can be divided into the oral vestibule (outside the dental arch) and the oral cavity proper (inside the teeth). Is bounded superiorly by the palate, inferiorly by the oral diaphragm and laterally by the cheeks.

3. The roof of the oral cavity:
the palate

4. incisive papilla:
pear-shaped swelling over the incisive foramen
palatine rugae:
several (3-7) transverse folds of the mucosa of the hard palate (choping and grinding of foods, phonation, sucking)
palatine raphe:
longitudinal mucosal fold in the midline
palatinae foveolae:
openings of the excretory
ducts of the small salivary
glands of palate

5. hard palate soft palate
palatine glands
hard palate
soft palate
fibromuscular structure covered by the pseudostratified ciliated columnar epithelium of the nasal cavity and the stratified squamous non-keratinized epithelium of the oral cavity

6. Bony base of hard palate
palatine proc. of maxillae
horizontal plate of palatine bone
median and transvers palatine sutures
incisive canal
greater and lesser palatine foramina
Most of the mammals have obvious incisive suture and incisive bone but in human tipically a complete fusion is seen. If observable, incisive bone consits of a body, a palatine process, an alveolar process and a nasal process.

7. Muscles of the soft palate
palatine aponeurosis
Uvula
Muscles of the
soft palate

8. palatine aponeurosis
1. Tensor veli palatini: medial plate of pterygoid proc., scaphoid fossa and cartilage of auditory tube →
in the palatine aponeurosis after a 90 degree turn at the hook of pterygoid proc.

9. M. tensor veli palatini
M. levator
veli palatini
M. palatopharyngeus
2. Levator veli palatini: inferior surface of the apex of petrous part of temporal bone and the cartilage of the auditory tube → palatine aponeurosis

10. Note the appearance of the levateor and tensor veli palatini muscles from an inferior aspect!

11. M. tensor veli palatini
M. levator
veli palatini
M. palatopharyngeus
3. Palatoglossus: connects the root of tongue with the palatine aponeurosis.
4. Palatopharyngeus: arises from the soft palate, radiates into the wall of pharynx.

12. M. tensor veli palatini
M. levator
veli palatini
M. palatopharyngeus
5. Uvularis muscles: originate from the posterior nasal spine and form the chief bulk of uvula

13. Innervation of palatine muscles
pharyngeal plexus:
CN IX-X-(XI)
Uvula
CN X. (VII. ?)
pharyngeal plexus:
CN IX-X-(XI)
CN X.

14. Note that arteries and nerves of the palate share the same name!
Innervation and blood supply of the palate
Descending palatine artery:
(labelled on the picture as greater
palatine artery)
from sphenoplatine branch of
maxillary artery coming from the
pterygopalatine fossa
Incisive artery
terminal branch of nasopalatine
artery arising from the spenopalatine
branch of maxillary artery
Ascending palatine artery
a direct branch from facial artery
Greater and lesser palatine nerves
from ganglionic branches of maxillary
nerve descending from the
Incisive nerve
nerve from ganglionic branches of
the maxillary nerve
Note that arteries and nerves of the palate share the same name!
All these vessels are the branches of the maxillary artery and are not asked in details in this semester. Similarly, nerves will be fully covered only durintg the 3rd semester!

15. The floor of the oral cavity:
the oral diaphragm

16. The main contributor of the oral diaphragm is the mylohyoid muscle (backwards it is replaced by the hyoglossus). Above the mylohyoid the two paralelly positioned geniohyoid muscles are seen, while anterior bellies of the digastric muscle are attached to the inferior surface of it.
(Tongue might be considered as a mucosa-covered muscular structure emerging from the oral floor.)

17. Lateral wall of the oral cavity:
the cheeks

18. Structure of the lips and cheeks is roughly the same, and we have already seen the lip in the histo lab!
Skin
stratified squamous keratinized epithelium, connective tissue papillae, sebaceous and sweat glands
Buccinator muscle
Mucosa
stratified squamous non-keratinized epithelium, connective tissue papillae, buccal glands

19. (oropharyngeal isthmus)
Isthmus of the fauces
(oropharyngeal isthmus)

20. As a GP sees…

21. As you see in the dissection room…
original position of oropharyngeal membrane
endoderm
ectoderm

22. The following structures should be identified: root of the tongue, palatoglossal and palatopharyngeal folds, tonsillary fossa, palatine tonsil, oropharynx

23. Lymphatic ring of Waldeyer

24. Tonsils
Tonsil or MALT (mucosa associated lymphatic tissue) or lymphoepithelial organ.
Right under the epithelium lymphoid cells are embedded into a reticular network formed by reticulum cells and reticular fibres. Lymphocytes destroy the basement membrane and infiltrate the epithelium resulting in a unique mixture of the epithelial and lympatic tissues.
The surface is increased by folds and invaginations.
The secondary follicles represent the B-dependent zones, among the follicles the T-dependent regions are present.

25. T-dependent zone
B-dependent zone

27. Blood supply of the (palatine) tonsils
(= descending palatine artery)

28. Clinical considerations

29. Relation of the palatine tonsil to the retropharyngeal and parapharyngeal spaces.

30. Tonsillectomy: removal of the palatine tonsil
uvula
palatine tonsil

31. Peritonsillar and retropharyngeal abscess

32. Thank you for your attention!