Glossopharyngeal nerve & its pathology ppt

Glossopharyngeal nerve

1. GOOD MORNING

2. Glossopharyngeal nerve & its pathology Presented by DR. D.Venkatesh kumar 1 st yr PG

3. CONTENTS Introduction Glossopharyngeal nerve Course & origin Nuclear columns & Functional components Branches & Distribution Applied aspects Conclusion References

4. INTRODUCTION The nervous system is an organ system containing a network of specialized cells called neurons that transmit signals between different parts of the body & co-ordinate the actions.

5. Structure of Nerve: Dendrites: Receptor segments that receive impulses from other neurons. Axons: Projecting segments that transmit impulses to other neurons .

6. Parts of the nerve: Epineurium Perineurium Endoneurium

7. CRANIAL NERVES The cranial nerves are a group of 12 paired nerves originating from the brain. The twelve cranial nerves are: I – Olfactory nerve II –Optic nerve III – Occulomotor nerve IV –Trochlear nerve V – Trigeminal nerve VI – Abducent nerve VII –Facial nerve VIII– Vestibulocochlear or Auditory nerve IX – Glossopharyngeal nerve X – Vagus nerve XI – Spinal accessory nerve XII– Hypoglossal nerve

8. Nerve fibers

9. Glossopharyngeal nerve Ninth cranial nerve. Mixed nerve. Motor root-basal plate of the embryonic medulla oblongata. Sensory root-cranial neural crest. Nerve of III branchial arch.

10. Course & Origin

11. Course & origin

12. J ugular foramen contents CN IX CN X CN XI Internal jugular vein Sigmoid sinus M eningeal branch from occipital and ascending pharyngeal arteries.

13. Nucleus of glossopharyngeal nerve

14. Nuclear columns & functional components

15. Branchiomotor Special visceral efferent (Nucleus ambigus ) Supply only one muscle – stylopharyngeus . Nuclear columns & functional components

16. Parasympathatic General visceral efferent (inferior salivatory nucleus) To supply parotid gland after relay in the otic ganglion.

17. General somatic afferent Spinal nucleus of CN V Carries proprioceptive impulses from pharyngeal muscle to spinal tract of V.

18. Viscerosensory (Nucleus of solitary tract) General visceral afferent &special visceral afferent Recives general sensations from post 1/3 rd of tongue, tonsil, pharynx, carotid body, taste sensation from post 1/3 rd of tongue.

19. Branches & Distribution Branch Supply Tympanic branch Middle ear, auditory tube,lesser petrosal nerve relay in otic ganglion join auriculotemporal nerve and supplies parotid gland. Sino carotid branch Carries Baroreceptors : carotid sinus Chemoreceptors : carotid body Tonsilary & palatal branches Supply sensory fibers to Palatine tonsil & soft palate.

20. Branches Supply Lingual branches Supply to posterior 1/3 rd of the tongue including circumvallate papillae. Pharyngeal branches Sensory to mucous membrane of pharynx. Muscular branches Stylopharyngeus muscle

21. Branches & Distribution

22. Functions of various branches of IX cranial nerve Auriculotemporal nerve provides various sensory innervations on the side of head. Baroreceptors are maintains blood pressure. Chemoreceptors are maintains chemical concentrations in blood.

23. Functions of various branches of IX cranial nerve Tonsil produce antibodies to kill germs and help to prevent throat and lung infections . Soft palate is responsible for closing of the nasal passage during act of swallowing and also for closing of the airway . Stylopharyngeous muscle elevates both pharynx and larynx

24. Applied aspects Glossopharyngeal nerve lesions Glossopharyngeal neuralgia Glossopharyngeal nerve paralysis.

25. Glossopharyngeal nerve lesions Difficulty in swallowing Loss of general sensation over posterior 1/3 rd of tongue, palate, pharynx. Loss of taste sensation over posterior 1/3 rd of the tongue. Dysfunction of tongue. Loss of gag reflux . Glossopharyngeal nerve lesions produce :

26. Glossopharyngeal neuralgia Similar to trigeminal neuralgia except the location. Pain is present on tonsil and ear. Pain is radiating from throat to ear because of tympanic branch of IX nerve. It is two types 1.Classical 2.Symptomatic

27. Classical type is obtained by arterial compression of the nerve at courses through jugular foramen Symptomatic type is obtain by under lying cause such as oropharyngeal tumors pagetic bone or calcified stylohyoid ligament .

28. Clinical features Rarely bilateral involvement. Episodic pain ,sharp, lancinating, and extreme intense. Pain during talking ,chewing, yawning, swallowing, touching a blunt instrument to tonsil. No definite trigger zone. Pt difficulty to localize the pain in oropharynx.

29. Diagnosis MRI scan of head CT scan of head X rays of arteries with dye( conventional angiography)

30. Treatment Medical : A nticonvulsant medications- Carbamazepine, Oxcarbazepine , Baclofen, Phenytoin, L amotrigine

31. Surgical 1. Micro vascular decompression 2. Surgical sectioning of glossopharyngeal nerve.

32. Glossopharyngeal paralysis Etiology – Diphtheria may cause IX nerve paralysis( Reversible) Diseases to lower brainstem Surgical procedures to tonsil. Symptoms – Loss of sensation from pharynx Decreased salivation Loss of taste sensation at post 1/3 rd of the tongue.

33. Conclusion Glossopharyngeal nerve is a ninth cranial nerve, which carries both sensory and motor functions. Any damage to this nerve leads to abnormalities in its function. So, proper care must be taken during surgical procedures to prevent these complications.

34. References 1. B.D.Chaurasia’s Human Anatomy, vol 3: 4th edition 2. Burket’s Oral Medicine- Diagnosis & Treatment – 10th ed. Martin S Greenberg & Michael Glick 3. Internet source 4. Gray’s anatomy– The anatomical basis of clinical practice 5. Shafer’s-A textbook of Oral Pathology. 6. Neville –A textbook of Oral and Maxillofacial Pathology , 1 st south asia edition 7. Thieme - Textbook of head and neck anatomy for dental medicine