v3 Flashcards
v3 contains BOTH sensory and motor nerve fibres, describe how the motor and sensory roots will EXIT the cranial cavity after they emerge from the trigeminal ganglion
the sensory root of V3 is on the inferior aspect of the trigaminal ganglion and motor root is medial to sensory
they leave the cranial cavity via the FORAMEN OVALE and then fuse together
then together they enter the INFRA TEMPORAL FOSSA
the infra temporal fossa is a highly important space which contains …
and communications with…
many muscles of mastication
the MAXILLARY ARTERY (not nerve) and its branches
the pterygoid plexus of veins (can be route for transmitting infection into the cranial cavity)
the MANDIBULAR nerve ( we target its branches in LA)
communicates MEDIALLY= with pterygopalatine fossa (links with V2)
POSTERIOR= with maxilla
LATERALLY= with ramus of mandible
SUPERIORLY= the infra temporal fossa is continuous with the temporal fossa at the level of zygomatic arch
mandibular nerve will branch into 2, one of these is the…
nerve to medial pterygoid
A MOTOR nerve which supplies the medial pteyrgoid
after giving off the 2 branches, the mandibular nerve will split into 2 important TRUNKS called the …
anterior trunk: smaller, mainly MOTOR, one sensory branch
posterior trunk: larger, mainly SENSORY, one motor branch
the one sensory branch of the anterior trunk of the mandibular nerve is the
LONG BUCCAL NERVE (ALL sensory)
this will pass anterior to ramus of mandible
what does the long buccal nerve supply
GS to
- BUCCAL gingivae ADJACENT to the mandibular molars
(therefore for extraction of mandibular molars, this nerve has to be anesthetised)
what do motor branches of the anterior trunk supply
motor supply to (muscles of mastication)
temporalis
lateral pterygoid muscle
masseter
(the medial pterygoid muscle is already supplied by V3 before it split by the NERVE TO MEDIAL PTERYGOID)
the posterior trunk has 3 large branches which are
which of these nerves are sensory/ motor/ mixed
- auriculotemporal nerve = ALL sensory
- lingual nerve= ALL sensory
- IAN = INITALLY mixed but ONLY SENSORY IN DISTAL regions
2 branches of the auriculotemporal nerve will run either side of which artery
the auriculotemporal nerve will split into 2 nerves, both of these will run either side of the MIDDLE MENGINGEAL ARTERY (branch of the MAXILLARY artery). its rupture inside the cranial cavity= extradural haemorrhage
what does the auticulotmeporal nerve supply
GS to
- TMJ
- auricle of ear
- temporal region of scalp/ temple (where it terminates)
how does the lingual nerve travel from the infratemporal fossa to the mandible
it runs inferiorly through the infratemporal fossa DEEP to the lateral pterygoid muscle
then it emerges out from the lateral ptyergoid muscle and runs antero-inferiorly between the middle pterygoid muscle and the ramus of the mandible
BUT at this point the lingual nerve IS STILL IN THE INFRATEMPRAL FOSSA and is ANTERIOR TO THE IAN
—> this spatial link with the IAN is key
will then run anterioly, so it is medial to the ROOT of the 3rd molar/ mandible (lingual nerve can be palpated at this point since it is just deep to oral mucosa)
AND 3rd molar closeness makes it vulnerable to damage when its being extracted
the lingual nerve will then DIVIDE into small branches
as the lingual nerve terminates it divides into small branches, what do they supply
GS
- lingual gingiva
- mucosa of the floor of mouth
- anterior 2/3 of tongue
how and where does the lingual nerve interact with the facial nerve
in the infratemporal fossa
- there the chorda tympani will join the lingual nerve as a mechanism to:
- –> transmit facial nerve secretomotor fibres to submandibular and sublingual glands AND
- –> receive taste fibres from the anterior 2/3 of tongue
describe how the IAN passes from the infra-temporal fossa to become the mental and then the incisive nerve
like lingual nerve, will pass deep to the lateral pterygoid muscle and then to the medial pterygoid and ramus of mandible
it will give off its initial motor fibres such as the nerve to myloyoid
then, IAN will enter the ramus of mandible via the MANDIBULAR FORAMEN on the medial surface of ramus
will run anteriorly through the body of the mandible, supplying the mandibular teeth as it goes, will then reach the mental foramen.
part of the IAN will emerge onto the soft tissues over the anterior aspect of mandible. this is called the MENTAL NERVE
after giving off the mental nerve, the IAN is now called the INCISIVE NERVE which will continue anteriorly inside the mandible
(the central incisor will receive DUAL INNERVATION from the left and right inscive nerves, this cross over impacts L.A.)
the initial (proximal) regions of the IAN contain both sensory and motor fibres
what do the motor fibres supply
motor fibres of IAN supply
- anterior belly of digastric muscle
- mylohyoid muscle via the nerve to mylohyoid (one of its branches)
