3rd year neuro 2019.ppt - ju medicine · bell’s palsy can occur as a result of tumors or aids?...
TRANSCRIPT
![Page 1: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/1.jpg)
Red nucleus • Rounded mass of gray
matter
• Situated bt cerebral
aqueduct and substantia
nigra
• Reddish blue(vascularity
& iron containing
pigment)
• Afferents from: cerebral • Afferents from: cerebral
cortex,cerebellum,substa
ntia nigra, thalamic
nuclei, spinal cord
• Efferent to: spinal cord,
reticular formation.
thalamus and substantia
nigra
• involved in motor
coordination.
![Page 2: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/2.jpg)
Crus cerebri
• Corticospinal &
corticonuclear
fibers (middle)
• Frontopontine
fibers (medial)
• Temporopontine
fibers (lateral)
these descending
tracts connect the
these descending
tracts connect the
cerebral cortex with
spinal cord, cranial
nerves nuclei, pons
& cerebellum
![Page 3: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/3.jpg)
Level at superior colliculus
� Superior colliculus
� Occulomotor nucleus
(posterior to MLF)
� Occulomotor n emerges
through red nucleus
� Edinger-Westphal
nucleus
� pretectal nucleus: close
to the lateral part of the
superior colliculus.superior colliculus.
� MLF
� Medial , trigeminal,
spinal leminiscus (no
lateral leminiscus)
� Red nucleus
� Substantia nigra
� Crus cerebri
� RF
![Page 4: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/4.jpg)
Substantia nigra� Large motor nucleus� is a brain structure
located in the midbrain� plays an important role in
reward, addiction, and movement.
� Substantia nigra is Latin for "black substance" due to high levels of melanin
� has connections with basal ganglia ,cerebral basal ganglia ,cerebral cortex
� Concerned with muscle tone
� Parkinson's disease is caused by the death of neurons in the substantianigra
![Page 5: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/5.jpg)
![Page 6: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/6.jpg)
Reticular Formation
• Deeply placed continuous network of nerve
cells and fibers that extend from the spinal
cord through the medulla, the pons, the
midbrain, the subthalamus, the
hypothalamus, and the thalamus
• Divided into three longitudinal columns:
� Median column: intermediate-size
neurons
Medial column: large neurons� Medial column: large neurons
� Lateral column: small neurons
• General function:
� Control of skeletal muscle
� Control of somatic and visceral sensations
� Control of the autonomic nervous system
� The reticular activating system.
![Page 7: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/7.jpg)
• Raphe nuclei
� Pallidus
� Obscurus
� Magnus
• Medial medullary
reticular area
� Central nucleus
of the medulla
Reticular FormationIn Medulla
of the medulla
� Gigantocellular
reticular nucleus
• Lateral medullary reticular area
� Ventrolateral reticular area
� Lateral reticular nucleus
� Parvocellular nucleus
![Page 8: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/8.jpg)
• Raphe nuclei
� Magnus
� Pontis
� Superior central
� Dorsal
• Medial medullary
reticular area
Reticular FormationIn Pons
� Gigantocellular
reticular nucleus
� Caudal
� Oral
• Lateral medullary reticular area
� Parvocellular nucleus
� Medial parabrachial nucleus
� Lateral parabrachial nucleus
![Page 9: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/9.jpg)
• Raphe nuclei
� Posterior (dorsal)
raphe nucleus:
anterior PAG
• Medial medullary
reticular area
� Cuneiform nucleus
� Subcuneiform
Reticular FormationIn Midbrain
� Subcuneiform
nucleus
• Participates in the ascending systems that:
• Regulate states of consciousness.
• Project to the thalamus (thalamic reticular nucleus)
• Ascending fiber system is largely responsible for maintaining an alert, wakeful state and thus forms part of the ascending reticular activating system
![Page 10: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/10.jpg)
Reticular Formation
•Deeply placed
posterior to the
olivary nucleus
•Widespread
connections
•Arousal of the •Arousal of the
brain as a whole
•Reticular activating
system (RAS)
•Maintains
consciousness
and alertness
![Page 11: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/11.jpg)
Oculomotor
Nerve (III)
• Main oculomotor nucleus
• Accessory parasympathetic nucleus (Edinger-Westphal nucleus)
![Page 12: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/12.jpg)
• Red nucleus
• Interpeduncular fossa
• Middle cranial fossa in the lateral wall of the cavernous sinus (Two rami)
• superior orbital fissure
Course of
occulomotor nerve
![Page 13: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/13.jpg)
Oculomotor
Nerve (III)
• Extrinsic muscles:
– The levator
palpebrae
superioris,
superior rectus,
medial rectus,
inferior rectus, and
inferior obliqueinferior oblique
• Intrinsic muscles:
– The constrictor
pupillae of the iris
and ciliary muscles
� Action:
� Lifting the upper eyelid; turning the eye upward, downward, and medially; constricting the pupil; and accommodating the eye
![Page 14: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/14.jpg)
• Complete lesion
– All of the muscles are paralyzed
except lateral rectus and superior
oblique
– Symptoms:
• External strabismus
• Diplopia
• Ptosis: drooping of the upper
Oculomotor
Nerve injury
• Ptosis: drooping of the upper
eyelid.
• The pupil is widely dilated
and nonreactive to light
• Accommodation of the eye is
paralyzed.� Incomplete lesions:
� Internal ophthalmoplegia: loss of
the autonomic innervation of the
sphincter pupillae and ciliary muscle
� External ophthalmoplegia.:
paralysis of the extraocular muscles
In cases of (diabetic neuropathy), the autonomic fibers are unaffected, whereas the nerves to the extraocular muscles are paralyzed.
![Page 15: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/15.jpg)
Trochlear
Nerve
Nucleus
• Location
� Pass posteriorly around the central gray matter
� Immediately decussates
![Page 16: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/16.jpg)
Trochlear
Nerve
• Supplies: superior
oblique muscle
• Action: turning
the eye
downward and
laterally
![Page 17: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/17.jpg)
• Symptoms:
– Diplopia
– Difficulty in turning the eye
downward and laterally.
– Difficulty in descending
stairs
– Head tilt to the side
Trochlear Nerve injury
– Head tilt to the side
opposite the paralsied eye
(compensatory adjustment)
![Page 18: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/18.jpg)
Abducent
NerveNucleus
� Location:
beneath the floor of the upper part of the fourth ventricle, close to the midline
![Page 19: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/19.jpg)
Course of
Abducent nerve
� Passes anteriorly: groove between the lower border of the pons and the medulla
oblongata
� Through the cavernous sinus, below and lateral to the internal carotid artery
� Superior orbital fissure
� Supplies the lateral rectus: turning the eye laterally
![Page 20: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/20.jpg)
• Symptoms:
– Diplopia
– Difficulty in turning the
eye laterally.
– internal strabismus.
unopposed medial
rectus pulls the eyeball
medially
Abducent Nerve injury
rectus pulls the eyeball
medially
![Page 21: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/21.jpg)
Trigeminal
Nerve Nuclei
• Main sensory nucleus
– Posterior part of the pons
(lateral)
• Motor nucleus
• Posterior part of the pons
(Medial)
• Spinal nucleus
– Superiorly: main sensory
nucleus
– Inferiorly: C2 segment
• Mesencephalic nucleus
– Lateral part of the gray
matter around the
cerebral aqueduct
– Inferiorly main sensory
nucleus
![Page 22: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/22.jpg)
Sensory
Components• Trigeminal sensory
ganglion: (Cell
bodies)
• Ascending
branches: main
sensory nucleus
• Descending
branches: spinal
nucleusnucleus
• Division:
– ophthalmic inferior
part of SN
– Maxillary: middle
part of SN
– Mandibular:
superior part of SN
� Touch and pressure: Main sensory nucleus
� Pain and temperature: Spinal nucleus
� Proprioceptive impulses from the muscles: mesencephalic nucleus
![Page 23: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/23.jpg)
![Page 24: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/24.jpg)
Motor
Components• Motor nucleus
receives
– Corticonuclear
fibers
– Red nucleus
– Reticular
formation
– Tectum
• Supplies
– Muscles of
mastication
– Tensor tympani
� Tensor veli palatini
� Mylohyoid
� Anterior belly of the digastric muscle
![Page 25: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/25.jpg)
Course of V
• Anterior aspect of the pons
• Upper surface of the apex
of the petrous bone
• Trigeminal ganglion: in
Meckel cave: pouch of dura
mater
• Divisions:
– Ophthalmic: superior – Ophthalmic: superior
orbital fissure
– Maxillary: foramen
rotundum
– Mandibular: foramen
ovale
![Page 26: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/26.jpg)
![Page 27: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/27.jpg)
176
![Page 28: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/28.jpg)
Facial Nerve
Nuclei
• Main Motor
Nucleus
• Deep in the
reticular
formation of the
lower part of the
pons
• The part of the • The part of the
nucleus that
supplies
– Upper part of
the face
receives
corticonuclear
fibers from
both
hemispheres.� lower part of the face receives only corticonuclear fibers from the
opposite cerebral hemisphere
![Page 29: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/29.jpg)
Facial Nerve
Nuclei
Parasympathetic
Nuclei:
• Location:
Posterolateral to
the main motor
nucleus
- superior
salivatory: salivatory:
receives from the
hypothalamus
- Lacrimal nucleus:
receives from
– hypothalamus
(Emotional)
– sensory nuclei of
the trigeminal
(reflex )
![Page 30: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/30.jpg)
Facial Nerve
NucleiSensory Nucleus:
• Location: upper
part of the
nucleus of the
tractus solitarius
• Sensations of
taste
– Cell bodies in
geniculate
Cell bodies in
geniculate
ganglion
– Sensory
Nucleus
– VPM
– Primary
gustatory
cortex (area
43)
![Page 31: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/31.jpg)
• Anterior surface
between the pons
and the medulla
oblongata
• Internal acoustic
meatus
• facial canal then
laterally through
the inner ear
Course of VII
![Page 32: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/32.jpg)
• Medial wall of
the tympanic
cavity
geniculate
ganglion
• Posterior wall
of the
tympanic
cavity
Course of VII
cavity
• Emerges from
the
stylomastoid
foramen.
![Page 33: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/33.jpg)
� Middle cranial fossa through the greater
petrosal foramen
� Passes over Foramen lacerum, where it joins deep petrosal nerve to form the nerve to pterygoid canal
Pterygoid canal
greater petrosal nerve
� continues through the petrotympanic fissure after which it emerges from the skull into the infratemporal fossa. It soon combines with the larger lingual nerve (Taste Anterior 2/3 of tongue)
The chorda tympani nerve
� Pterygoid canal
� Pterygopalatine gangilion
� Maxillary nerve
![Page 34: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/34.jpg)
![Page 35: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/35.jpg)
� Location of the lesion:
� Abducent and the facial
nerves are not functioning:
lesion in the pons:
� Vestibulocochlear and the
facial nerves are not
functioning: lesion in the
internal acoustic meatus
� Loss of taste over the
anterior two-thirds:
Facial Nerve injury
anterior two-thirds:
damaged to the chorda
tympani branch
� Upper vs lower motor neuron
injury
![Page 36: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/36.jpg)
� Usually unilateral
� Lower motor neuron type of facial paralysis.
� Cause is not known,
� Exposure of the face to a cold draft?
� Complication of diabetes?
Bell’s Palsy
� Can occur as a result of tumors or AIDS?
![Page 37: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/37.jpg)
• Conducts nerve impulses from
(inner ear)
� Utricle and saccule:
orientation of the head
relative to gravity (linear
accelerations)
� Semicircular canals:
rotational head movements
(angular accelerations)
Vestibular nerve
Vestibulocochlear nerve (VIII)
(angular accelerations)
• Cell body in vestibular ganglion
(Scarpa ) in internal acoustic
meatus
• Vestibular Nuclear Complex
� Lateral
� Superior
� Medial
� Inferior
![Page 38: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/38.jpg)
• Efferent fibers from the
Vestibular Nuclei
� Cerebellum
� Spinal cord
(vestibulospinal tract)
� Nuclei of (III, IV, VI)
nerves through the MLF
� Cerebral cortex:
Vestibular nerve
Vestibulocochlear nerve (VIII)
� Cerebral cortex:
vestibular area in the
postcentral gyrus just
above the lateral fissure
via VPL of thalamus
![Page 39: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/39.jpg)
• Conducts nerve impulses
from (inner ear)
� organ of Corti in the
cochlea
• Cell body in spiral ganglion
of the cochlea
• Cochlear Nuclei
� Anterior cochlear
Cochlear nerve
Vestibulocochlear nerve (VIII)
� Anterior cochlear
nucleus
� Posterior cochlear
nucleus
![Page 40: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/40.jpg)
Vestibulocochlear nerve (VIII)
� Emerge from ponto-meduallry junction
� Runs laterally in the posterior cranial fossa
� Enter internal acoustic meatus
![Page 41: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/41.jpg)
Glossopharyngeal
Nerve Nuclei
• Main Motor
Nucleus
• Deep in the
reticular formation
of the medulla
oblongata
• superior end of the
nucleus ambiguusnucleus ambiguus
• receives
corticonuclear
fibers from both
cerebral
hemispheres.
• supply the
stylopharyngeus
muscle
![Page 42: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/42.jpg)
Parasympathetic Nuclei:
• Inferior salivatory
nucleus
• receives afferents
from the
hypothalamus
• efferent
preganglionic
Glossopharyngeal
Nerve Nuclei
preganglionic
parasympathetic
fibers reach the otic
ganglion through the
tympanic branch the
glossopharyngeal
nerve
![Page 43: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/43.jpg)
• The tympanic
plexus, and the
lesser petrosal
nerve
• Middle cranial
fossa, then
throught foramen
ovale to
infratemporal auriculotemporal nerve V
Tympanic canaliculusHiatus for Lesser petrosal nerve
infratemporal
fossa
• Postganglionic
fibers pass to the
parotid salivary
gland.
![Page 44: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/44.jpg)
Glossopharyngeal
Nerve Nuclei
• Sensory Nucleus
part of the nucleus
of the tractus
solitarius
• Taste from
posterior 1/3 of
tongue
• Cell body in inferior • Cell body in inferior
glossopharyngeal
ganglion
• Sensory nucleus
• Thalamus
• lower part of the
postcentral gyrus
![Page 45: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/45.jpg)
Glossopharyngeal
Nerve Nuclei
• Sensory Nucleus part
of the nucleus of the
tractus solitarius
• Afferent impulses
from the carotid
sinus (baroreceptor)
• Cell body in inferior
glossopharyngeal glossopharyngeal
ganglion
• Sensory nucleus
• connected to dorsal
nucleus of the vagus
nerve (carotid sinus
reflex
![Page 46: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/46.jpg)
Glossopharyngeal
Nerve Nuclei
• Common sensation
• Cell body in
Superior
glossopharyngeal
ganglion
• spinal nucleus of
the trigeminal
nervenerve
• Thalamus
• postcentral gyrus
Sensation from- middle ear- Auditory tube- Pharynx except nasopharynx- Posterior 1/3 of tongue
![Page 47: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/47.jpg)
Course of IX
� Anterolateral surface of the upper part of the medulla oblongata
� Groove between the olive and the inferior cerebellar peduncle
� Leaves the skull through the jugular foramen
� Posterior border of the stylopharyngeus muscle
� Between the superior and middle constrictor
� Sensory to the oropharynx laryngopharynx and the posterior 1/3 of the tongue
lesion of the glossopharyngeal
nerve:
� Loss of pharyngeal reflex
(gag reflex).
� Loss of carotid sinus reflex.
� Loss of taste in the posterior
third of tongue (Vallate
papillae).
![Page 48: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/48.jpg)
197
![Page 49: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/49.jpg)
Vagus Nerve
Nuclei• Main Motor
Nucleus
• Deep in the
reticular formation
of the medulla
oblongata
• Lower part of
nucleus ambiguus
Receives • Receives
corticonuclear
fibers from both
cerebral
hemispheres.
• Supply the
constrictor muscles
of the pharynx and
the intrinsic
muscles of the
larynx
![Page 50: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/50.jpg)
Parasympathetic Nuclei:
• Dorsal nucleus of the
vagus
• floor of the lower
part of the fourth
ventricle
• Receives afferents
from:
Vagus Nerve
Nuclei
from:
– Hypothalamus
– glossopharyngeal
nerve (carotid sinus
reflex).
� Efferent to involuntary muscle of the bronchi, heart, esophagus, stomach, small intestine, and large intestine as far as the distal one-third of the transverse colon
![Page 51: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/51.jpg)
Vagus Nerve
Nuclei• Sensory Nucleus
Lower part of the
nucleus of the
tractus solitarius
---Taste from epiglottis.
• Cell body in inferior
ganglion of vagus
• Sensory nucleus
• Thalamus• Thalamus
• Postcentral gyrus
-- common sensation
• superior ganglion of
vagus
• Spinal nucleus of the
trigeminal nerve.� outer ear�mucosa of the larynx�Dura of Posterior cranial fossa
![Page 52: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/52.jpg)
� Anterolateral surface of the upper part of the medulla oblongata
� Groove between the olive and the inferior cerebellar peduncle
� Leaves the skull through the jugular foramen
� descends vertically in the neck within the carotid
Course of X
Lesion of Vagus:
� Uvula deviates to the healthy side.
� Hoarseness of voice
� Dysphagia and nasal regurgitation
� Arrhythmia in heart and irregularity
in GI tract because
![Page 53: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/53.jpg)
Accessory Nerve
cranial root
• nucleus ambigus
• Receives
corticonuclear
fibers from both
cerebral
hemispheres.
• anterior surface of • anterior surface of
the medulla
oblongata between
the olive and the
inferior cerebellar
peduncle
• joins the vagus
nerve
![Page 54: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/54.jpg)
Accessory Nerve
Spinal root
• spinal nucleus
(anterior gray
column of upper
five cervical
segments
• Receives
corticospinal fiberscorticospinal fibers
from ipsilateral
cerebral
hemisphere.
![Page 55: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/55.jpg)
Accessory Nerve
Course
• spinal root emerge
from the spinal
cord between the
anterior and
posterior nerve
roots of the cervical
spinal nerves
• Enters the skull • Enters the skull
through the
foramen magnum
• joins the cranial
root
� Leaves the skull through jugular foramen, then separates into:
� Cranial root: joins the vagus
� Spinal root: supplies sternocleidomastoid and trapezius muscles
![Page 56: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/56.jpg)
Hypoglossal nucleus
• Beneath the floor
of the lower part of
the fourth ventricle
• Receives
corticonuclear
fibers from both
cerebral
hemispheres.hemispheres.
• Cells responsible
for supplying the
genioglossus
muscle receives
from opposite
cerebral
hemisphere
![Page 57: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/57.jpg)
Hypoglossal
Nerve
Course• anterior surface of
the medulla
oblongata
• between the
pyramid and the
olive
• leaves the skull
through the through the
hypoglossal canal
• between the
internal carotid
artery and the
internal jugular
vein
![Page 58: 3rd year neuro 2019.ppt - JU Medicine · Bell’s Palsy Can occur as a result of tumors or AIDS? • Conducts nerve impulses from (inner ear) Utricle d s cule: orientation of the](https://reader033.vdocuments.site/reader033/viewer/2022041720/5e4dd4e6213e34147570276d/html5/thumbnails/58.jpg)
Hypoglossal Nerve injury
� Lower motor neuron lesion
– Tongue deviation toward the
paralyzed side
– Muscle atrophy (ipsi)
� Upper motor neuron lesion
– No atrophy– No atrophy
– On protrusion tongue will
deviate to the side opposite
the lesion