Maxillary and Mandibular divisions of the Trigeminal nerve

What is the corneal reflex

-protective blink reflex which is triggered when the cornea is touched or irritated

-prevents damage to the eye

Which nerve is responsible for the sensory (afferent) arm of the corneal reflex

CNV1 (detects irritation of the cornea)

Which nerve is responsible for the motor arm of the corneal reflex

CNVII (closes eyelids via the orbicularis oculi)

What are sneeze and cough reflex

involuntary,protective mechanism designed to clear the respiratory tract of irritants, allergens and pathogens

Which nerves are responsible for the sensory arm of sneeze eflexe

CNV- detects irritation of the nasal mucosa (causes sneezing)

Which nerves are responsible for the motor arm of the sneeze reflex

CNV- closes eyes

CNX- larynx and pharynx

phrenic nerve- diaphrgm

causes you to sneeze

What nerve is responsible for the sensory arm of the cough reflex

CNX- detects irritation int he lower airway fromt he larynx, trachea and bronchi

Which nerves are responsible for the motor arm of the cough reflex

CNX- larynx, controls the glottis

phrenic nerve- diaphragm

What is the jaw jerk reflex

-tap the chin and this causes the jaw to close

Sensory arm of the jaw jerk reflex

CNV3- detects stretch when the chin is tapped

Where does CNV3 send this information to

mesencephalic nucleus of CNV in the brainstem

Motor arm of the jaw jerk reflex

CNV3- goes to muscles of mastication causing them to contract and the jaw to close

Which structures are supplied by CNV2

maxillary teeth

maxillary sinus

nasal cavity

palate

cheek, lower eyelid, upper lip

Function of the meningeal branch of CNV1

sensory innervation to the dura of the anterior cranial fossa, anterior part of the falxi cerebri and part of the tentorium cerebelli

provides pain sensation from the meninges

Describe the pathway of CNV2 from the trigeminal ganglion to entering the orbit

1. leaves trigeminal ganglion

2. travels in lateral wall of cavernous sinus

3. exits skull via foramen rotundum and enters pterygopalatine fossa

4. enters the orbit via the inferior orbital fissure

What are the branches coming directly off of CNV2

-meningeal branch

-infraorbital branch

-posterior superior alveolar nerve

Once CNV2 passes through the inferior orbital fissure, what does it become

the infraorbital nerve

Describe the pathway of the infraorbital nerve

passes through the infraorbital groove then travels anteriorly infraorbital canal

exits the face via the infraorbital foramen

What are the 3 terminal branches of the infraorbital nerve

-inferior palpebral

-external nasal

-superior labial

Which other branches are given off by the infraorbital nerve and where are these branches given off

middle superior alveolar nerve

anterior superior alveolar nerve

given off in the infraorbital canal

Function of the middle and anterior superior alveolar nerve

innervates the maxillary teeth

middle superior alveolar also innervates the maxillary sinus

Which branch of CNV2 is given off before it exits the skull via the foramen rotundum

the meningeal branch

Function of the meningeal branch of CNV2

provides sensation to the dura mater of the middle cranial fossa

Where does the zygomatic nerve branch off and describe its pathway

branches off CNV2 in the pterygopalatine fossa, enters orbit via the inferior orbital fissure, runs along lateral orbital wall

What are the 2 terminal branches of the zygomatic nerve

zygomaticotemporal nerve

zygomaticofacial nerve

Functino of the zygomaticotemporal nerve

sensory innervation to the skin of the temple region

Function of the zygomaticofacial nerve

sensory innervation to the skin over the cheek

Which other branch is given off by the zygomatic nerve

communicating branch to the lacrimal nerve

Function of the communicating branch

Allows fibres from the greater petrosal nerve of CNVII (after synapsing in the ptg ganglion) to hitchike onto CNV2 and join the lacrimal nerve to then supply the lacrimal gland

Function of the posterior superior alveolar nerve

innervates maxillary sinus

innervates the molar teeth and their adjacent buccal gingivae

Where does the posterior superior alveolar nerve branch

branches directly off of CNV2 at the pterygopalatine fossa

Pathway of the posterior superior alveolar nerve

exits ptg fossa through the pterygomaxillary fissure

enters the infratemporal fossa

travels laterally and inferiorly to enter the posterior surface of the maxilla

Function of the nasopalatine nerve

innervates the medial wall of the nasal cavity

innervates the mucosa, gingiva and glands near to the incisors

Where does the nasopalatine nerve branch off

Branches of CNV2 when it passes through the pterygopalatne ganglion

Pathway of the nasopalatine nerve

1. enters the nasal cavity via the sphenopalatine foramen

2. descends to the roof of the mouth through the incisive canal

3. exits into the oral cavity via the incisive foramen

Function of the greater palatine nerve

hard palate and palatal gingiva of upper teeth

Where does the greater palatine nerve branch and describe its pathway

Branches off CNV2 as it passes through the ptg ganglion

1. runs inferiorly from the ptg ganglion

2. goes through the greater palatine canal

3. exits onto the hard palate via the greater palatine foramen

Function of the lesser palatine nerve

sensory innervation to the soft palate, uvula

Where does the lesser palatine nerve branch off and describe its pathway

Branches off of CNV2 as it passes through the ptg ganglion

1. runs inferiorly from the ptg ganglion

2. descends through the greater palatine canal

3. emerges from the lesser palatine foramen

Function of the posterior superior lateral nasal nerve

supplies upper lateral wall of the nasal cavity (superior and middle concha region)

Where does the posterior superior lateral nasal nerve branch off of and describe it pathway

branches off of CNV2 where it passes through the pterygopalatine ganglion

passes through the sphenopalatine foramen to reach the lateral wall of the nasal cavity

Function of the posterior inferior lateral nasal nerve

supplies the lower lateral wall of the nasal cavity (inferior meatus region)

Where does the posterior inferior lateral nasal nerve branch off of

branches off of the greater palatine nerve within the greater palatine canal

passes through a foramen in the palatine bone to reach the lateral wall of the nasal cavity

Function of the pharyngeal branch of CNV2

provides sensory innervation to the mucosa of the superior nasopharynx

Where does the pharyngeal branch branch off

Branches off of CNV2 from the posterior part of the ptg ganglion

What is the nerve of the pterygoid canal

formed by the junction of the greater petrosal nerve and deep petrosal nerve within the pterygoid canal which then joins the posterior part of the ptg ganglion

Which type of fibres make up the nerve of the pterygoid canal

greater petrosal nerve- preganglionic parasympathetic fibres from CNVII which synapse in the ptg ganglino

deep petrosal nerve- preganglionic sympathetic fibres from the internal carotid plexus that don’t synapse in the ptg ganglion

Explain how the postganglionic parasympathetic fibres form the greater petrosal nerve are distributed (after synapsing)

Distributed to nasal and palatal glands via the greater and lesser palatine nerve and the nasopalatine nerve

Distributed to the lacrimal gland by joining the zygomatic nerve and joining the communicating branch to the lacrimal nerve

After passing throught the foramen ovale, what does CNV3 divide into

divides into a posterior and anterior division

Branches of the anterior division of CNV3

deep temporal nerves

buccal nerve

nerve to lateral pterygoid (supplies lateral pterygoid)

masseteric nerve (supplies masseter)

Function of the deep temporal enrves

innervate the temporalis muscle

Function of the buccal nerve

purely sensory- innerates the skin over the cheek, buccal mucosa

Which nerves branch off of the main trunk of CNV3

nervus spinosus

nerve to medial pterygoid

Function of the nervus spinosus

sensory innervation to posterior half of dura mater in the middle cranial fossa

How does the nervus spinosus reenter the cranial cavity

via the foramen spinosum (along with the middle meningeal artery)

Function of the nerve to medial pterygoid

motor innervation to the medial pterygoid, tensor tympani and tensor veli palatini

Branches of the posterior division of CNV3

lingual nerve (general sensation to anterior 2/3 of the tongue)

inferior alveolar nerve

auriculotemporal nerve

Pathway of inferior alveolar nerve

1. gives off nerve to mylohyoid muscle before entering mandibular canal

2. enters mandible via mandibular foramen

3. travels through mandibular canal

4. divides into 2 branches incisive nerve and mental nerve which exits at the mental foramen

Function of mental nerve

sensory innervation to skin of chin and lower lip

Function of incisive nerve

sensory innervation to anterior teeth

Function of nerve to mylohyoid

motor innervation to mylohyoid and anterior belly of the digastric muscle

Branches of the auriculotemporal nerve

auricular branches

articular branches

superficial temporal branches

Function of the auricular branches

general sensation to parts of the external ear

function fo the sueprficial temporal branches

sensory innervation to skin of the temple region

Function of the articular branches

sensory innervation to the TMJ

Relevance of the lesser petrosal nerve to CNV3

1. preganglionic parasympathetic fibres of the lesser petrosal nerve travel to the otic ganglion where they synapse

2. postganglionic fibres hitchike onto the auriculotemporal nerve to reacht he parotid gland

Relevance of the chorda tympani to CNV3

chorda tympani hitchikes onto the lingual nerve to reach the submandibular ganglion where it synapses

postaganglionic fibres supply the submandibular and sublingual glands

What is inferior alveola nerve block

numb the inferior alveolar nerve by injecting near where it enters the mandibular foramen