Brainstem II 2004 - Bellarmine University · Brainstem Nuclei Descending Input Descending Input. 10...
Transcript of Brainstem II 2004 - Bellarmine University · Brainstem Nuclei Descending Input Descending Input. 10...
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Brainstem IIMedical NeuroscienceDr. Wiegand
Internal Brainstem
Cranial nerve nucleiLocation of selected tractsReticular formation
Developmental Organization
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Developmental Organization
SulcusLimitans
Developmental Organization
From Pritchard &Alloway: Fig. 4-1
From Pritchard &Alloway: Fig. 4-1
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Cranial Nerve Nuclei Organization
Medial to sulcus limitans
GSE ⇒ SVE ⇒GVE
Lateral from sulcus limitans
VA ⇒ GSA ⇒SSA
From Pritchard &Alloway: Fig. 4-4
From Pritchard &Alloway: Fig. 4-4
MOTSEN
Generalizations
Sensory nuclei lateral to sulcus limitansMotor nuclei medial to sulcus limitansVisceral nuclei are on either side of sulcusInnervation of skeletal muscle (GSE & SVE) most medialGeneral and special visceral afferent nuclei in same column
Cranial Nerves –Telencephalon & Diencephalon
Olfactory –smell (SVA)
Optic –vision (SSA)
I, II
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Cranial Nerves –Mesencephalon
Oculomotor –extraocular eye muscles (GSE) –oculomotor nucleusPSNS to eye (GVE) –Edinger-Westphalnucleus
Trochlear –extraocular muscle (sup. oblique) (GSE) –trochlear nucleus
III, IV
Cranial Nerves –Metencephalon
Trigeminal –Masticatory muscles (SVE) – trigeminal motor nucleus General sensation of the head and face (GSA) – trigeminal complex
Abducens –extraocular muscle (lat. rectus) (GSE) –abducens nucleus
V, VI
Cranial Nerves –Metencephalon
Facial –Facial expression muscles (SVE) – facial motor nucleusGlands (submandibular, sublingual & lacrimal) (GVE) – superior salivatory & lacrimal nucleusTaste (SVA) – rostral solitary nucleusGeneral sensation of ear (GSA) – trigeminal complex
VII
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Cranial Nerves –Metencephalon
Vestibulocochlear –Hearing (SSA) –dorsal and ventral cochlear nucleiBalance (SSA) –vestibular nuclei
VIII
Cranial Nerves –Mylencephalon
GlossopharyngealStylopharyngeus muscle (SVE) – n. ambiguusPSNS to parotid gland (GVE) – inferior salivatory n. Taste (SVA) – rostral solitary n.Carotid body sensation (GVA) – caudal solitary n.General sensation from ear & tongue (GSA) –trigeminal complex
IX
Cranial Nerves –Mylencephalon
VagusMuscles of larynx & pharynx (SVE) – n.ambiguusPSNS to thorax and upper abdomen (GVE) – dorsal motor n. of X (DMV)Sensory from viscera (GVA) – caudal solitary n.Taste (SVA) – rostralsolitary n.General sensation from ear (GSA) - trigeminal complex
IX
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Cranial Nerves –Mylencephalon
Accessory –innervates trapezius and sternocleidomastoid (SVE or GSE) – motor nucleus of XI in upper cervical cord
Hypoglossal –tongue muscles (GSE) –hypoglossal nucleus
XI, XII
Cranial Nerve Nuclei GroupsGSE & SVE – Motor Nuclei of:
III, IV, V, VI, VII, XI, XII ambiguus
GVE – Parasympathetic NucleiEdinger-Westphal nucleusLacrimal & salivatory (superior, inferior) nuclei Dorsal Motor Nucleus of X
SVA (Taste) – Rostral Solitary nucleusGVA – Caudal Solitary nucleusGSA – Trigeminal (TBNC)SSA – Cochlear and Vestibular nuclei
Tongue mm.NoneHypoglossalMotorhypoglossalXII
Trap & SCMnoneaccessory nucleusmotor accessoryXI
Mm of larynx/pharynxViscera
EpiglottisViscera sensory
External ear
nonemultiple
inf. (nodose) of Xinf. (nodose) of Xsup. (jugular) of X
n. ambiguousdorsal motor
rostral solitarycaudal solitary
trigeminal
motorPSNStaste
sensorysensory
vagusX
Mm of larynxParotid gland
TongueSoft palate & pharynx
External ear
noneotic
inf. (petrosal) of IXinf. (petrosal) of IX
n. abiguusinferior salivatory
rostral solitarycaudal solitary
trigeminal
motorPSNStaste
sensorysensory
glossopharyngealIX
Cochlea Vestibular app
spiralvestibular
cochlear (dorsal, ventral) & vestibularhearingbalance
vestibulocochlearVIII
Mm facial expressLacrimal gland
Submandibular/lingualTongue
External ear
nonesubmandibular and sphenopalatine
geniculate
facialsuperior salivatory
-rostral solitary
trigeminal
motorPSNStaste
sensory
facialVII
Lateral rectus mmnoneabducensMotorabducensVI
Mm of masticationSensory of face
nonetrigeminal
motor VSpV, PrV, mesV
MotorSensory
trigeminalV
Superior obliqueNoneTrochlearMotortrochlearIV
Extraocular mmConstr. Pup & ciliary
noneciliary
oculomotorEdinger-Westphal
MotorPSNS
oculomotorIII
Retinaretinalateral geniculate bodyvisionopticII
Nasal cavityolfactory bulb-smellolfactoryI
PeripheralTargetPeripheral GangliaNucleusFunctionNameNumber
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Learning Internal Anatomy
Recognize outline of brainstemMidbrain
• Inferior vs. superior colliculiPonsMedulla
• Open vs. closedPlace nuclei in correct levelRecognize orientation of sliceLearn Pathways
Relationship of tractsPlaces of decussation
http://lansing.bellarmine.edu/pt/atlas/cover.html
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Sensory NucleiSensory DecussationMedial LemniscusAnterolateral System
ASCENDING PATHWAYS
Spinocerebellar Tracts
Corticospinal &Corticobulbar Tracts(Pyramidal Tract)
DESCENDING PATHWAY
CRANIAL NERVES
Edinger-Westphal NucleiOculomotor NucleiTrigeminal NerveTrigeminal NucleiHypoglossal NucleusDorsal Motor of VagusSolitary Nucleus
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Red nucleusRed nucleus
SubstantiaNigra
SubstantiaNigra
Inferior olivarynucleus
Inferior olivarynucleus
Other Brainstem Nuclei
Reticular Formation
Diffuse, poorly differentiated brainstem nucleiOccupies tegmentum of brainstemModulates:
PainMuscle tone and reflexesAutonomic functions e.g. respiration, blood pressure, cardiac functionArousal, awareness and attention
Reticular Formation
Raphe
med
ial m
ediallate
ral lateral
Ascending Input
Ascending Input
Cerebellarprojecting
nuclei
Cerebellarprojecting
nuclei
Spinal Cord & Brainstem Nuclei
Forebrain & Brainstem Nuclei
Descending Input
Descending Input
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Midline Raphe Nuclei
Mostly serotoninergiccells – send and receive extensive ascending and descending projectionsRegulate pain, arousal and sleep
Parasagittalmedial nuclei
Motor regulationMedial (facilitates extensors) reticulospinaltractLateral (facilitates flexors) reticulospinal tractAlso autonomic regulation
ARAS exerts excitatory input to cortex for consciousness and attention
Regulates attentionInhibits pain at spinal cord levelRegulates autonomic function
Locus Ceruleus & Medial Reticular Zone
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ParasagittalLateral Nuclei
Receives input to mediate visceral and cranial nerve reflexesProjects to parasagittal medial nucleiPedunculopontine n.
Acetylcholine projecting cellsAscending projection to inferior frontal cortex/intralaminar n.Input from basal ganglia output nucleiProjects to brainstem motor nuclei (VST, RST)
PedunculopontineNucleus
Wallenberg’s Syndrome
Thrombosis of PICA
Lateral medullarysyndrome
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Wallenberg’s Syndrome
Structures involved:Inf. Cerebellar peduncle (ipsilateral ataxia)SpV tract & nucleus (ipsilateral loss pain & temperature)Anterolateral system (contralateral loss of body pain & temperature)N. ambiguus (dysphagia & dysphonia)Vestibular n. (nystagmus and postural instability)
Well…