презентация Trygemini

1. TheThe trigeminal nervetrigeminal nerve (the(the fifthfifth cranialcranial nervenerve) is) is
responsible for sensation in the face. It is similarresponsible for sensation in the face. It is similar
to theto the spinalspinal nervesnerves C2–S5C2–S5, which are responsible, which are responsible
for sensation in the rest of the body.for sensation in the rest of the body.

2. FunctionFunction
 The fifth nerve is primarily a sensory nerve,The fifth nerve is primarily a sensory nerve,
but it also has certain motor functions (biting,but it also has certain motor functions (biting,
chewing and swallowing).chewing and swallowing).
 The sensory function of the trigeminal nerve isThe sensory function of the trigeminal nerve is
to provide the tactile,to provide the tactile, proprioceptiveproprioceptive, and, and
nociceptivenociceptive afference of the face and mouth.afference of the face and mouth.
 The motor function, on the other hand, is toThe motor function, on the other hand, is to
activate muscles of theactivate muscles of the mandiblemandible..

3. Peripheral anatomyPeripheral anatomy
 TheThe trigeminal nervetrigeminal nerve is the largest of theis the largest of the
cranialcranial nervesnerves. It has three major branches:. It has three major branches:
 thethe ophthalmicophthalmic nervenerve (V1)(V1)
 thethe maxillarymaxillary nervenerve (V2)(V2)
 thethe mandibularmandibular nervenerve (V3).(V3).

5. ophthalmicophthalmic nervenerve (V1)(V1)
 NasociliaryNasociliary nervenerve
 sensory root of ciliary ganglionsensory root of ciliary ganglion
 posterior ethmodial nerveposterior ethmodial nerve
 long ciliary nervelong ciliary nerve
 infratrochlear nerveinfratrochlear nerve
 anterior ethmoidal nerveanterior ethmoidal nerve
 lacrimal nervelacrimal nerve
 frontal nervefrontal nerve
 supratrochlear nervesupratrochlear nerve
 supraorbital nervesupraorbital nerve

6. maxillarymaxillary nervenerve (V2),(V2),
 In the craniumIn the cranium
 MiddleMiddle meningealmeningeal nervenerve
 In the pterygopalatine fossaIn the pterygopalatine fossa
 ZygomaticZygomatic nervenerve ((zygomaticotemporalzygomaticotemporal nervenerve,, zygomaticofacialzygomaticofacial nervenerve))
 Two small branches to theTwo small branches to the pterygopalatinepterygopalatine ganglionganglion (sometimes called(sometimes called
the sphenopalatine ganglion)the sphenopalatine ganglion)
 PosteriorPosterior superiorsuperior alveolaralveolar nervenerve
 In the infraorbital canalIn the infraorbital canal
 AnteriorAnterior superiorsuperior alveolaralveolar nervenerve
 MiddleMiddle superiorsuperior alveolaralveolar nervenerve
 On the faceOn the face
 InferiorInferior palpebralpalpebral nervenerve
 ExternalExternal nasalnasal nervenerve
 SuperiorSuperior labiallabial nervenerve

8. mandibularmandibular nervenerve (V3).(V3).
 The mandibular nerve gives off the following branches:The mandibular nerve gives off the following branches:
 From the main trunk of the nerveFrom the main trunk of the nerve
 nervusnervus spinosusspinosus (meningeal branch)(meningeal branch)
 medialmedial pterygoidpterygoid nervenerve
 nerve tonerve to tensortensor tympanitympani
 nerve tonerve to tensortensor veliveli palatinipalatini
 From the anterior divisionFrom the anterior division
 massetericmasseteric nervenerve
 deepdeep temporaltemporal nervesnerves (anterior and posterior)(anterior and posterior)
 buccalbuccal nervenerve (a sensory nerve)(a sensory nerve)
 laterallateral pterygoidpterygoid nervenerve
 From the posterior divisionFrom the posterior division
 auriculotemporalauriculotemporal nervenerve
 linguallingual nervenerve
 inferiorinferior alveolaralveolar nervenerve
 motor branch tomotor branch to mylohyoidmylohyoid and anterior belly ofand anterior belly of digastricdigastric muscles (muscles (mylohyoidmylohyoid nervenerve))
 The mandibular nerve also gives off branches to theThe mandibular nerve also gives off branches to the oticotic ganglionganglion

11.  The ophthalmic and maxillary nerves are purely sensory. The mandibularThe ophthalmic and maxillary nerves are purely sensory. The mandibular
nerve has both sensory and motor functions.nerve has both sensory and motor functions.
 The three branches converge on theThe three branches converge on the trigeminaltrigeminal ganglionganglion (also called the(also called the
semilunar ganglionsemilunar ganglion oror gasserian gangliongasserian ganglion), which contains the cell), which contains the cell
bodies of incoming sensory nerve fibers. The trigeminal ganglion isbodies of incoming sensory nerve fibers. The trigeminal ganglion is
analogous to theanalogous to the dorsaldorsal rootroot ganglia of the spinal cord, which contain theganglia of the spinal cord, which contain the
cell bodies of incoming sensory fibers from the rest of the body.cell bodies of incoming sensory fibers from the rest of the body.
 From the trigeminal ganglion, a single large sensory root enters theFrom the trigeminal ganglion, a single large sensory root enters the
brainstem at the level of thebrainstem at the level of the ponspons. Immediately adjacent to the sensory. Immediately adjacent to the sensory
root, a smaller motor root emerges from the pons at the same level.root, a smaller motor root emerges from the pons at the same level.
 Motor fibers pass through the trigeminal ganglion on their way toMotor fibers pass through the trigeminal ganglion on their way to
peripheral muscles, but their cell bodies are located in the motor nucleus ofperipheral muscles, but their cell bodies are located in the motor nucleus of
the fifth nerve, deep within the pons. Motor fibersthe fifth nerve, deep within the pons. Motor fibers gogo together with sensorytogether with sensory
fibers in branches of the mandibular nerve.fibers in branches of the mandibular nerve.
 The areas of cutaneous distribution (The areas of cutaneous distribution (dermatomesdermatomes) of the three branches of) of the three branches of
the trigeminal nerve have sharp borders with relatively little overlapthe trigeminal nerve have sharp borders with relatively little overlap
(unlike dermatomes in the rest of the body, which show considerable(unlike dermatomes in the rest of the body, which show considerable
overlap).overlap).

12. Sensory branches of the trigeminalSensory branches of the trigeminal
nervenerve
 The ophthalmic, maxillary and mandibularThe ophthalmic, maxillary and mandibular
branches leave the skull through three separatebranches leave the skull through three separate
foraminaforamina: the: the superiorsuperior orbitalorbital fissurefissure, the, the
foramenforamen rotundumrotundum and theand the foramenforamen ovaleovale. The. The
mnemonicmnemonic standing room onlystanding room only can be used tocan be used to
remember that V1 passes through the superiorremember that V1 passes through the superior
orbital fissure, V2 through the foramenorbital fissure, V2 through the foramen
rotundum, and V3 through the foramen ovale.rotundum, and V3 through the foramen ovale.

13.  TheThe ophthalmicophthalmic nerve carries sensory information from the scalp andnerve carries sensory information from the scalp and
forehead, the upper eyelid, the conjunctiva and cornea of the eye, the noseforehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose
(including the tip of the nose), the nasal mucosa, the frontal sinuses, and(including the tip of the nose), the nasal mucosa, the frontal sinuses, and
parts of theparts of the meningesmeninges (the(the duradura and blood vessels).and blood vessels).
 TheThe maxillarymaxillary nerve carries sensory information from the lower eyelid andnerve carries sensory information from the lower eyelid and
cheek, thecheek, the naresnares and upper lip, the upper teeth and gums, the nasal mucosa,and upper lip, the upper teeth and gums, the nasal mucosa,
the palate and roof of the pharynx, the maxillary, ethmoid and sphenoidthe palate and roof of the pharynx, the maxillary, ethmoid and sphenoid
sinuses, and parts of the meninges.sinuses, and parts of the meninges.
 TheThe mandibularmandibular nerve carries sensory information from the lower lip, thenerve carries sensory information from the lower lip, the
lower teeth and gums, the floor of the mouth, the anterior ⅔ of the tongue,lower teeth and gums, the floor of the mouth, the anterior ⅔ of the tongue,
the chinthe chin,, parts of the external ear, and parts of the meninges. Theparts of the external ear, and parts of the meninges. The
mandibular nerve carriesmandibular nerve carries touch/positiontouch/position andand pain/temperaturepain/temperature sensationsensation
from the mouth. It does not carryfrom the mouth. It does not carry tastetaste sensation, but one of its branches,sensation, but one of its branches,
thethe linguallingual nervenerve carries multiple types of nerve fibers that do not originatecarries multiple types of nerve fibers that do not originate
in thein the mandibularmandibular nervenerve. Taste fibers from the anterior 2/3 of the tongue. Taste fibers from the anterior 2/3 of the tongue
are initially carried in theare initially carried in the linguallingual nervenerve (which is anatomically a branch of(which is anatomically a branch of
V3), but then enter theV3), but then enter the chordachorda tympanitympani, a branch of, a branch of cranialcranial nervenerve VIIVII..

15. Motor branches of the trigeminal nerveMotor branches of the trigeminal nerve
 Motor branches of the trigeminal nerve are distributed in theMotor branches of the trigeminal nerve are distributed in the mandibularmandibular
nervenerve. These fibers originate in the. These fibers originate in the motor nucleus of the fifth nerve,motor nucleus of the fifth nerve,
which is located near the main trigeminal nucleus in the pons. The motorwhich is located near the main trigeminal nucleus in the pons. The motor
branches of the trigeminal nerve control the movement of eight muscles,branches of the trigeminal nerve control the movement of eight muscles,
including the fourincluding the four musclesmuscles ofof masticationmastication..
 Muscles of masticationMuscles of mastication
 massetermasseter
 temporalistemporalis
 medial pterygoidmedial pterygoid
 lateral pterygoidlateral pterygoid
 OtherOther
 tensortensor veliveli palatinipalatini
 mylohyoidmylohyoid
 anterior belly of digastricanterior belly of digastric
 tensor tympanitensor tympani
 With the exception of tensor tympani, all of these muscles are involved inWith the exception of tensor tympani, all of these muscles are involved in
biting, chewing and swallowing. All have bilateral cortical representation.biting, chewing and swallowing. All have bilateral cortical representation.

16. Trigeminal nucleusTrigeminal nucleus

17. Trigeminal nucleusTrigeminal nucleus
 AAll sensory information from the face (all touch/positionll sensory information from the face (all touch/position
information and all pain/temperature information) is sent toinformation and all pain/temperature information) is sent to
thethe trigeminaltrigeminal nucleusnucleus.. The nucleus is divided anatomicallyThe nucleus is divided anatomically
into three parts, visible in microscopic sections of theinto three parts, visible in microscopic sections of the
brainstem. From caudal to rostral (i.e., going up from thebrainstem. From caudal to rostral (i.e., going up from the
medulla to the midbrain) they are themedulla to the midbrain) they are the spinal trigeminalspinal trigeminal
nucleusnucleus, the, the main trigeminal nucleusmain trigeminal nucleus, and the, and the
mesencephalic trigeminal nucleusmesencephalic trigeminal nucleus..
 The three parts of the trigeminal nucleus receiveThe three parts of the trigeminal nucleus receive differentdifferent
typestypes of sensory information. The spinal trigeminal nucleusof sensory information. The spinal trigeminal nucleus
receives pain/temperature fibers. The main trigeminal nucleusreceives pain/temperature fibers. The main trigeminal nucleus
receives touch/position fibers. The mesencephalic nucleusreceives touch/position fibers. The mesencephalic nucleus
receives proprioceptor and mechanoreceptor fibers from thereceives proprioceptor and mechanoreceptor fibers from the
jaws and teethjaws and teeth

18. Spinal trigeminal nucleusSpinal trigeminal nucleus
 TheThe spinalspinal trigeminaltrigeminal nucleusnucleus representsrepresents pain/temperaturepain/temperature
sensation from the face. Pain/temperature fibers fromsensation from the face. Pain/temperature fibers from
peripheralperipheral nociceptorsnociceptors are carried in cranial nerves V, VII, IX,are carried in cranial nerves V, VII, IX,
and X. On entering the brainstem, sensory fibers are groupedand X. On entering the brainstem, sensory fibers are grouped
together and sent to the spinal trigeminal nucleus. The spinaltogether and sent to the spinal trigeminal nucleus. The spinal
trigeminal nucleus contains atrigeminal nucleus contains a pain/temperature sensory mappain/temperature sensory map
of the face and mouth. From the spinal trigeminal nucleus,of the face and mouth. From the spinal trigeminal nucleus,
secondary fibers cross the midline and ascend in thesecondary fibers cross the midline and ascend in the
trigeminothalamic tracttrigeminothalamic tract to the contralateral thalamus. Theto the contralateral thalamus. The
trigeminothalamic tract runs parallel to thetrigeminothalamic tract runs parallel to the spinothalamicspinothalamic
tracttract, which carries pain/temperature information from the, which carries pain/temperature information from the
rest of the body. Pain/temperature fibers are sent to multiplerest of the body. Pain/temperature fibers are sent to multiple
thalamic nuclei.thalamic nuclei.

19. Somatotopic representationSomatotopic representation
 Information from the face and mouth is represented inInformation from the face and mouth is represented in
the spinal trigeminal nucleusthe spinal trigeminal nucleus
 Within the spinal trigeminal nucleus, information isWithin the spinal trigeminal nucleus, information is
represented in anrepresented in an onion skinonion skin fashion. The lowestfashion. The lowest
levels of the nucleus (in the upper cervical cord andlevels of the nucleus (in the upper cervical cord and
lower medulla) represent peripheral areas of the facelower medulla) represent peripheral areas of the face
(the scalp, ears and chin). Higher levels (in the upper(the scalp, ears and chin). Higher levels (in the upper
medulla) represent more central areas (nose, cheeks,medulla) represent more central areas (nose, cheeks,
lips). The highest levels (in the pons) represent thelips). The highest levels (in the pons) represent the
mouth, teeth, and pharyngeal cavity.mouth, teeth, and pharyngeal cavity.
 The spinal trigeminal nucleus sends pain/temperatureThe spinal trigeminal nucleus sends pain/temperature
information to theinformation to the thalamusthalamus

20. Main trigeminal nucleusMain trigeminal nucleus
 TheThe mainmain trigeminaltrigeminal nucleusnucleus representsrepresents touch/positiontouch/position
sensation from the face. It is located in the pons, close to thesensation from the face. It is located in the pons, close to the
entry site of the fifth nerve. Fibers carry touch/positionentry site of the fifth nerve. Fibers carry touch/position
information from the face and mouth (via cranial nerves V,information from the face and mouth (via cranial nerves V,
VII, IX, and X) are sent to the main trigeminal nucleus whenVII, IX, and X) are sent to the main trigeminal nucleus when
they enter the brainthey enter the brain..
 The main trigeminal nucleus contains aThe main trigeminal nucleus contains a touch/positiontouch/position
sensory mapsensory map of the face and mouth, The main nucleus isof the face and mouth, The main nucleus is
analogous to the dorsal column nuclei (the gracile and cuneateanalogous to the dorsal column nuclei (the gracile and cuneate
nuclei) of the spinal cord, which contain a touch/position mapnuclei) of the spinal cord, which contain a touch/position map
of the rest of the body.of the rest of the body.
 From the main trigeminal nucleus, secondary fibers cross theFrom the main trigeminal nucleus, secondary fibers cross the
midline and ascend in the trigeminal leminiscus to themidline and ascend in the trigeminal leminiscus to the
contralateral thalamus.contralateral thalamus.

21. Mesencephalic trigeminal nucleusMesencephalic trigeminal nucleus
 Only certain types of sensory fibers have cellOnly certain types of sensory fibers have cell
bodies in the mesencephalic nucleus:bodies in the mesencephalic nucleus:
proprioceptor fibers from the jaw andproprioceptor fibers from the jaw and
mechanoreceptor fibers from the teeth. Somemechanoreceptor fibers from the teeth. Some
of these incoming fibers go to the motorof these incoming fibers go to the motor
nucleus of V, thus entirely bypassing thenucleus of V, thus entirely bypassing the
pathways for conscious perception.pathways for conscious perception.