7. Cranial Nerves 3/ Cavities, Sensation and Secretion Flashcards
Function of trigeminal nerve?
Primary function:
- Sensation to the head and cavities (general somatic afferent)
- Motor to muscles of mastication (special visceral efferent)
Additional functions:
- Carrier of Autonomic Fibres
- Parasympathetic (general visceral efferent)
- Anterior 2/3 Taste/Gustation (special visceral afferent). Produced by CN VII but carried by CN V
What is the function so CN VII and nervus intermedius?
Primary functions:
- Motor to Muscles of Facial Expression (special visceral efferent)
Additional functions:
- Parasympathetic (general visceral efferent)
- Anterior 2/3 Taste/Gustation (special visceral afferent). Sensation produced here.
What are the nuclei used by the CN V?
General Somatic Afferent to the MESENCEPHALIC, CHIEF SENSORY & SPINAL nuclei in the midbrain, pons & medulla oblongata
Special Visceral Efferent from the MOTOR nucleus in the pons to the muscles of mastication (derived from 1st pharyngeal arch)
CN V is the carrier for parasympathetic & taste fibres originating in the _______ ________component of CN VII
CN V is the carrier for parasympathetic & taste fibres originating in the nervus intermedius component of CN VII
Where is the trigeminal ganglion found?
In Meckel’s cave (within dura mater) on the apex of the petrous temporal bone
What are the nuclei and modalities of the CN VII?
Special Visceral Efferent from the MOTOR nucleus in the pons to the muscles of FACIAL EXPRESSION & a few additional muscles such as the stapedius, stylohyoid & posterior belly of digastric (all derived from 2nd pharyngeal arch)
What are the nuclei and modalities of CN VII with Nervus Intermedius?
General Visceral Efferent (parasympathetic) from the SUPERIOR SALIVATORY NUCLEUS in the PONS to the lacrimal gland, nasal & oral cavities (mucous membranes), sinuses, submandibular & sublingual salivary glands
Special Visceral Afferent to the SOLITARY NUCLEUS in the MEDULLA OBLONGATA receiving TASTE from the anterior 2/3 of the tongue (via the chorda tympani nerve)
What are the 4 PS ganglion of the head?
Ciliary: Fibres of the edinger-westphal nucleus assocatied with CN III
Pterygopalatine: Receives from CN VII
Submaxillary: Receives from CN VII
Otic: Receives from CN IX
What is the geniculate ganglion?
The geniculate ganglion contains fibres for taste and somatic sensation and is located in the petrous temporal bone.
Fibres in:
- Facial nerve (labyrinthine segment)
- Nervus intermedius
Fibres out:
- Facial nerve (tympanic segment)
- Greater superficial petrosal nerve
- Lesser petrosal nerve
- External petrosal nerve
What is the course of the greater petrosal nerve?
Branches from nervus intermedius of CN VII in the geniculate ganglion.
- -> Escapes from the middle ear and lies on the surface of the petrous temporal bone in the middle cranial fossa
- -> Passes through foramen lacerum
- -> Heads towards the pterygoid canal
Function of the greater petrosal nerve?
Greater petrosal nerve, from the nervus intermedius of CN VII, carries:
- General visceral efferent (PS secretomotor) fibres that contribute to the innervation of the LACRIMAL GLAND
- Special visceral afferent (GUSTATION/TASTE) fibres from the palate
Greater petrosal & deep petrosal nerves combine as the nerve of the ______ _______
Greater petrosal & deep petrosal nerves combine as the nerve of the pterygoid canal
What gives off the deep petrosal nerve?
SYMPATHETIC PLEXUS on the internal carotid artery in the carotid canal
Which two nerves are found int he pterygopalatine fossa?
Nerve of the pterygoid canal (combination of deep and greater petrosal nerve, passing through the pterygoid canal)
+
CN V2 (that has passed through the foramen rotundum)
Position of the pterygopalatine fossa?
Pterygopalatine fossa lies just LATERAL to the upper aspect of the NASAL cavity & NASOPHARYNX behind the ORBIT & above the hard/soft PALATE
What is the input and output at the pterygopalatine ganglion?
- PREGANGLIONIC parasympathetic fibres from the nervus intermedius of CN VII (via the greater petrosal & nerve of pterygoid canal) synapse in the pterygopalatine ganglion
- POSTGANGLIONIC fibres hitch-hike with branches of the CN V2 and some branches of CN V1.
Output to:
-Orbit (lacrimal gland)
-Maxilla (sinus, palate, upper teeth and gums)
-Nasal cavity
-Nasopharynx
All branches of CN ____ are also accompanied by branches of the maxillary artery
All branches of CN V2 are also accompanied by branches of the maxillary artery
Where is the pterygopalatine ganglion found?
Pterygopalatine ganglion is within the pterygopalatine fossa
What is the innervation fo the lacrimal gland?
- Lacrimal nerve, a branch of CN V1
2. Zygomaticotemporal (from the zygomatic of CN V2 that joins the lacrimal nerve)
What nerve supplies the frontal sinus?
The supraorbital nerve (branch of the frontal nerve from CN V1)
What supplies the ethmoidal sinuses, lateral wall of nasal cavity & nasal septum?
Anterior ethmoidal nerve with posterior ethmoidal nerve behind it
How do other nerves & vessels enter & leave the nasal cavity?
Cribiform plate, nares, incisive canal, sphenopalatine foramen, palatine canal
Cribriform plate: Olfactory nerves & anterior ethmoidal nerve
Nares: Branches of the facial artery and infraorbital nerve
Incisive canal: The nasopalatine nerve passes to the anterior aspect of the palate and terminal branches of the greater palatine atery enter the nasal cavity
Sphenopalatine foramen: Medial to the pterygopalatine fossa for the passage of artery (sphenopalatine) & branches of CN V2 (nasopalatine)
Palatine canal: Nasal branches of the greater palatine nerve with arteries pass from the palatine canal through small foramina
What provides the lateral nervous supply to the nasal wall?
Anterior and superior:
From CN V1 via the anterior ethmoidal nerve
Posterior and inferior:
From CN V2 mainly via the greater palatine nerve
Olfactory nerves are capable of ________!
Olfactory nerves are capable of regeneration!
Shingles (herpes zoster) at the tip of the nose may herald corneal involvement. Why?
Anterior ethmoidal nerve continues as the external nasal nerve that supplies the tip of the nose.
Anterior ethmoidal is a branch of the nasociliary (CN V1) that supplies the cornea
What is the nervous supply to the medial nasal wall and septum?
Anterior, superior:
From nasal nerves of CN V1
Posterior, inferior:
-From nasal nerves of CN V2 mainly via nasopalatine nerve
What accompanies the CN V2 branches that supply the anterior and superior medial nasal wall?
CN V2 branches are accompanied by branches of the MAXILLARY branch of the EXTERNAL carotid artery
What accompanies the CN V1 branches that supply the anterior and superior medial nasal wall?
CN V1 branches are accompanied by branches of the OPHTHALMIC branch of the INTERNAL carotid artery
Innervation of the palate?
Hard and soft palate:
Greater & lesser palatine branches of CN V2 (plus secretomotor from the pterygopalatine ganglion) supply
Anterior palate:
Nasopalatine nerve
The ___________ nerve (CN IX) supplies the tonsils & may encroach onto the soft palate (referred pain to middle ear)
The glossopharyngeal nerve (CN IX) supplies the tonsils & may encroach onto the soft palate (referred pain to middle ear)
What supplies the sphenoidal sinuses?
CN V1 and V2
What supplies the maxillary sinus
The INFRAORBITAL nerve along with the SUPERIOR ALVEOLAR nerves (anterior, middle & posterior) on their way to the teeth & gums
Where does the chorda tympani (CN VII) nerve join the lingual nerve (CN V)?
In the infratemporal fossa
What is the nervous supply of the lingual nerve (branch of CN V3)?
- General somatic sensation
from anterior 2/3 of tongue, floor of mouth mucosa & mandibular lingual gum - Carrier of general visceral efferent (parasympathetic secretomotor) to sublingual & submandibular glands
- Carrier of special visceral afferent for taste of anterior 2/3 of tongue via chorda tympani nerve (CN VII nervus intermedius )
The lingual nerve (CN V3) enters the oral cavity between which 2 muscles?
Mylohyoid and hyoglossus
What is the innervation of the salivary glands?
Lingual nerve:
- Preganglionic parasympathetic fibres leave the lingual nerve & synapse in the submandibular ganglion
- Postganglionic branches pass to the submandibular & sublingual salivary glands
Oral cavity innervation?
CN V3 dividing just below the foramen ovale into lingual & inferior alveolar (dental) nerves
The INFERIOR ALVEOLAR NERVE supplies the:
-Lower teeth emerging as mental nerve to skin of chin & lower lip (both skin & mucous membranes)
-Mylohyoid
-Anterior belly of digastric
