Term
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Definition
| conduit function (pathways ascending /descending), cranial nerve function , integrative function ( Monitosrs BP, periph, o2 level, tries to correct and adjust). |
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Term
| brainstem is surroudned by CSF |
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Definition
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Term
| ventricle pathway and lcoations |
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Definition
| draining form lateral ventricle to foramen of monroe into third ventricle in diencephalic portion of forerain, now drains into fourth ventricle . Aqueduct conencts 3rd and foruth ventricle. Foruth ventricle palced on surface of pons and one portion of medulla. Fourth ventricle portion only present on rostral medulla, caudal medulla will hae central canal. |
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Term
| Cisterna magna location and pathway to cisterna magna |
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Definition
| Fourth ventricle ondorsal surface of the pons- fourth ventricle now goes through opening into one cistern itno subarachnoid space surrounding the brain. This C portion is called cisterna magna- biggest cistern of all. Positiond below cerebellum- Second spotto take CSF. |
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Term
| pontine cistern, interpeduncular cistern and quadrigeminal cistern |
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Definition
| D is pontine cistern, A and B are interpeduncular sistern, dorsal side – lamina quadrigemina- quardimnila cistern. pon |
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Term
| Medulla ventral veiw from medial to lateral |
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Definition
| Form medial to lateral you see one bumpy structure closet o midline (pyramids). Laterally we see the olives. Ifnerior cerebellar peduncle lateral to olive. |
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Term
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Definition
| ee junction with the pons (pntomedulalry juciton). This groove is important as certain number of cranial nerves emerge from this groove. F |
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Term
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Definition
| inside is snakeish structure - accumulation of nuclei - inferior olvie nuclus- cell bodies from thsi nucleus wil lgive rise to axons, come togetehr and cross to the contralteral side, joining third bump on ventral surface (inferior cerebellar peduncle). |
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Term
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Definition
| Myeliantedfiers in medulla are coming from cortex. Cell bodies from corte x on surface of the brain give off axons come down through internal capsule through midbrain through pons and come out at ventral side of medulla as pyrmaids. Between rostral and caudal it will start to cross at certain elvel. Pyramidal decucsation = borderline between medulla and spinal cord |
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Term
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Definition
| marks end point of ventral medulla and start of spnal cord |
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Term
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Definition
| Corticonuclear pathway- starts in cortex, will end in brainstem. Basic function- voluntary control of facial muscles. Mostly bilateral. Mostly crossed for cranial nerve XII (in medulla). In medulla Cranial nerve XI it is ipsilateral |
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Term
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Definition
| vshaped structure – floor of fourth ventricle. Fasiculus cunueatus- to Cuneate Tubercule, FG, GT, and cross section. |
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Term
| cross s ection of medulla |
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Definition
| internal acruate ibers accumulate in medial lemniscus which is position on dorsal part of the periyarmids and medial to inferior olivary nucleus. |
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Term
| spinothalamic tract location |
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Definition
| posterolateral to inferior oliv |
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Term
| hitns to tell you uare in emdulla |
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Definition
| look for inferior olivary nucleus (snakesih structure). lower part: look for pyrammidal decussation and circularity of spinal cord |
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Term
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Definition
| motor and sensory innercation for somatic and visceral structures |
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Term
| brainstem autonomic fiber organization |
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Definition
| Only autonomic fibers emerging from the brian stem are parasympathetic . There are somatic and visceral efferent fibers. |
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Term
| visceral efferent subtypes |
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Definition
| general : preganglioinic parasympathetic – cranial thoracic, aabdmoinal smooth muscle. 2. Special- activated striated muscle (muscles of facial expression, jaw msucls, etc. |
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Term
| brainstem afferent organization |
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Definition
| Sensory afferent nuclei- impulses travelling towards the brain. – somatic and visceral inneration. : visceral and somatic afferents have general and special aprts |
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Term
| somatic afferent subdivisions |
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Definition
| General- pain, temp , touch presusre for face. Special- specialized snesnory systems specifically vision and hearing. |
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Term
| visceral afferent subdivisions |
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Definition
| General- chemo/baroreceptors for high/low BP- high/low level of oxygen in blodosream. Special- smelland taste |
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Term
| cranial nerve classification |
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Definition
| sensory, mixed , or motor. mnemonic for 2-12: Soem Say Money Matters But My Borther Says Big Brains Matter Most |
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Term
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Definition
| 2;2;4;4. I and II are outside brainstem. Midbrain: III and IV . Pons: 4 cranialnerveS: 5,6,7,8. Medulla: 9,10,11,12. |
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Term
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Definition
| Nuceli of these crnail nerves are distributed within the brainstem. Expect to find 3 and 4 in midbrain. But there is one exception.- V will have some nuclei throughout all three parts of brainstem – even reachin spinal cord. If you look at this group of nulcei, they are more lateral than this goru pof nucleci- this is how sensory and motor modalities are spit in position fob brainstem. AL lthe sensory nuclei are morea lteral than motor nuclei. – Motor-Medial. |
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Term
| cranial nerves ventral veiw |
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Definition
| Outside the brainstem. rOstral caudal position and emerging of these nerves. Most rostral part- III and IV, will emerge on the ventral side, just one is coming out of diorsal . Ventral side=III, on dorsal side= number IV. Following four nerves will find in pons. V will be emrging on lateral side. Remaining 3 dedicated to pons will come out of pontomedullary junction. Walkf rom media to lateral : 5,6,7,8,. Remainign four will be emerging in the medulla: walk from VIII down to IX X XI, XII will come out medially (so it is motor nerve) |
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Term
| medulla cranil neres slide |
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Definition
| Medulla crnial nerves: we see pyramdis, we see the olive lateral to pyramid. Hypoglossal- coming out between pyramid and olive. If look at dorsal side of medulla, we are already familiar with fasciles , if we look in the floor of the fourth ventricle we will define the first triangle- dedicated to hypoglossal nerve.- hypoglossal triangle. |
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Term
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Definition
| If walk all the way back we see fourth ventricle opening- we have this bump/triangle- it forms the hypologssal nucleus |
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Term
| hypoglossal nucleus medulla dorsal veiw |
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Definition
Hypooglossal nuclus – axial cut- we are looking at just oen level of that nulcues0 that nucleus is not just one rounded structure, it is a cell column that is extending through all medulla from rostral part to more caudal part where foruth ventricle is gone.
If make a cut at more rostral elvel of medulla. Seep osition of hypoglossal nucleus |
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Term
| Hypogossal nucleus path from dorsal to ventral |
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Definition
| from hypoglossal nuclus , cell bodies will give rise to efferent axons- exiting out these axons will come together and go out between inferior olive and pyramids out as we saw on ventral side of the medulla |
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Term
| Hypoglossal nucleus function |
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Definition
hypoglossal nucleus innerates ipsilateral mmuscle of the tongue, to control movement and maintain muscle tone of tongue.
Cranil nerve XII innervates all intrinsic and all BUT one extrinsic tongue muscles.
The command will be coming from corticobulbar axons. |
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Term
| Innervation fo hypoglossal nucleus |
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Definition
| from Cortionuclear pathway. Remember that it is Contralateral innercation! Also by reticular neurons for automatic/refelx movements. |
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Term
| damage to tongue inneration |
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Definition
Lesion specific for hypoglossal nerve. Corticobulbar shown in pink will be coming form the cortex down and will cros to innervate the contralateral hypoglossula n ucelaus in the medulla. Hypoglossul nucleus gives rise to hypoglossol nerve coming out between pyramdis nad inferior olives, and this left nerve will innervate the left part of the tongue.
What happens if u have UMN (corticobulbar tract). Lesion of left corticobulbar tract innerating righth ypoglossual nucleus, will lsoei nnervation to right half of the tongue. If lose force one side , the strong side will push against the weaker side. I UMNwill move to side opposite the lesion.
LMN- ipsilateral damage. Diagnose difference based on UMNL and LMNL specific signs (atrophy for lMN is biggest marker) |
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Term
| bilateral lesions of hypoglossal |
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Definition
| Bilateral lesion of hypoglossal nerve- considerable disability in speaking , severe swallowing difficulty of food. |
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Term
| common cuases of CN XII lesions |
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Definition
| Most common causes of CN XIII lesions – motor neuron disease , demyelination, bleeding ,tumros ofm edullan ad ase of the skull. |
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Term
| medulla cranial nerves slide accesory nerve |
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Definition
| - accessory nerve , has long roots that are coming form spinal codrd up and are being joined by fibers from the medulla |
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Term
| accesory nucleus and cranial nerve XI |
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Definition
| Caudal medulla cross section- there is pyramidal decucsation, accessory nucleus (lateral) giving rise to the brainstem of the accessory nerve that will be joined by the medial motor nuclei of the ventral horn of c1-5. (combined spinal cranial nerve) |
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Term
| spinal accesory nerve function |
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Definition
| Function of spinal accessory nerve: this nerve is used tom ove shoulders up . also innerves larynx |
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Term
| effect of spinal accesory nerve lesion |
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Definition
| ON ipsilateral side where have lesion of this nerve, your shoulders will be hanging down on (the shoulder that is injured . ALso cannot rotate head to healthy side. Also voice hoa rsen ess |
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Term
| Meulal cranial enrves cranial nerve |
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Definition
| Cranial X – vagus exit aboe XI ventrally. On the dorsal side we learned the first triagnel that is sittitng in the base of the fourth ventricle the hypoglossal triangle. Lateral to the hypoglossal triangle is the vagal triangle. |
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Term
| Vagus carnial NErve X components of the mixed nerve (efferent portion |
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Definition
Motor and sensory components. Two efferent motor ocmponents: Both visceral. General visceral efferents will be preganglionic parasympathetic . All pregnaglinic parts will go to al lthe ganglia of the body (heart lungs, gI) to the level of splenic flexure.
Special visceral efferent – muscles pharyngleal/laryngeal msucles, play a role inswaloign and vocalization. |
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Term
| vagus nerve X mixed nerve components (afferent) |
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Definition
| 3 afferant components: General somatic afferent- pharynx, meninges, small region of external ear. SVA- taste fro mepiglottis and pharynx. GVA- chemoreceptors and barorecpetors of the aortic arch |
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Term
| vagus cranial X- mixed Cross section of rostral medulla, location of vagus nuceleus |
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Definition
| Cross section of rostral medulla- Dorsal side is fourth ventricle and hypoglossal trigone. If you move lateral form hypoglossal trigoine will find vagal trigone- is formed from dorsal motor nucleus of X. Its position si lateral to hypoglossal nucleus. These two trigones correspond to the corresponding nuclei. Vagal nucleusi s not rounded nucleus it is a cell column just adjacent ot hypoglossal nucleus cell column . There is a dorsal vagus X cell column . |
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Term
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Definition
| GVE- the X you can seeh ere is coming form the portion of the medulla onteh lateral side above the accessory nerve (the dorsal motor nucleus).a on the lateral side you have this blue axons part of the vagus covering al lthese organs up to the splenix flexure .IT is giving ridse to preganglionic parasympathetic for lungs for erspiraotry pathways, it will rpodive constriction fo patwhasy it will slow downHR , it will promote digestion. |
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Term
| what is difference between paraysmpathetic and symapthetic? |
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Definition
| The differncei s postganglionic fibers- symp-norep. Parasymp- Ach. Secodn fiff: sympathetic ganglia are close to spinal cord, parasympathetic ganglia are closet o target organs. |
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Term
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Definition
| Second function is the swallwoign and vocalization. nucleus ambigus. Positioned at dorsal part of inferior olviaryn ucelus. Axosn will come out and join ten, but will innervate muscles of pharynx and larynx. This nucleus amibgious is a cell column that will give riset o al lthese axosn coming out as vagal nerve |
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Term
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Definition
| SVA- taste from epiglottis and posterior pharynx, GVA- baro and chemoreceptors signallign form the peripheray will go into nucleus solitarus . Solitary nucleus is described as donut, with accumulation of fibersi n middle part surrounded by ce lbodiesm akign nucleus solitares. In center is solitary tract- fibers comignform periphearry giving connections to cell bodies surroudnign it. The position of nucleus solitaius is very close to dorsal motor nucleus of X. |
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Term
| nucleus solaitrus distrubiton/appearance |
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Definition
| It makes a smiley face if you oook across medulla. Has rostral , caudal and joining part. taste will go into more rostrala part of solitary nucleus while the baroreceptors and chemoreceptors will go into more cadual part of solitary nucleus |
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Term
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Definition
| . HWen put in head and face. mMost of the ataste is covered by the tongue. Bu t vagus is providing information to small aprt of pharyngeal space (epiglottis) . Like in the peripehray sensory enrves the first neuron will be outside the central nerouvs system .itw il lbe outside the brasinstem . it will sit in its own vagal ganglion. IT wil lahve pseudounipolar neuron with peripheral branche picking up information about taste from eppiglotis ahtat will travel for the central branch and end up in solitary nucleus of medulla.r |
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Term
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Definition
| Bilateral lesion of agus is fatal. If you have unilateral lesion of vagus nerve , will be widespread dysfunction of muscles that are inenrated. Manifestaion: uvula will deviate to contraltearl side of lesion of vagus. Right side of vocal muscles paralysis |
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Term
| glossopharyngeal nerve lcoation |
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Definition
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Term
| glosspharyngeal motor division |
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Definition
| innervated posteriortongue adn pharynx. General Visceral efeerent – preganglionic parasympathetic fibers and Special viscearal efferent. Disference : will only give out one for one ganglion for parotid gland. SVE- are basically dedicated to some msucles of pharynx. |
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Term
| glossopharyngeal sensory division |
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Definition
3 seneosry afferents: GSA- small region of external ear, SVA- taste (posterior one third of tongue) and pharynx. ,
GVA- chemoreceotprs and brorepcetors of the carotid body |
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Term
| Glosopahryngeal nerve GVE |
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Definition
| GVE for only one gland – parotid gland. . Fibers are coming from PONS not medulla. Cell bodies give fibers diving down exiting at the level of the medulla providing the innervation for the preganglion for the ganglion for the parotid. Iti s inferior salviatory nuclesus. |
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Term
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Definition
| muscles involved in pharynx and pollick movements during talking and swallowing (simlair to vagus). Same nucleus as vagus (nucleus amibigous), and same column. |
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Term
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Definition
| taste for posterior 1/3 of the tongue. Taste goesi tn orostral part of nucleus solitarus together with ten. |
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Term
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Definition
| chemorecpetors andbaroreceptors of the carotid body . Chemoreceptors and baroreceptors will go intoc caudal parto f smiley face (nucleus soliaturs?) also with 1-. |
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Term
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Definition
| Epiglottis innervated by X, Posterior one third is covered by nine. remaining taste will be coming will be entering nucleus osltiarus from number VII. All enter nucleus solitarus |
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Term
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Definition
| similiar to hypoglossus. glossalpharyngeal overshooting, - neuralgia where you can have episodes of throat and ear pain |
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Term
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Definition
| Medulla summary- multinucleated that was talked about. Red oen ishypoglossal nucleus, yellow one is the dorsal motorn ulceus of texn, herei s thambigious contributing to both ien and ten. IF make borderline at dorsal surface (sulcas limitans), all this motor nuclei are more medial and sensory lateral |
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Term
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Definition
| border betewen motor and sensory protinos of medulla |
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Term
| developemnt of medullar relations |
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Definition
| CNS develops from neural tube. This neural tube is surrounded b y two accumulations of cell bodies. More ventral parts are called basal plate, and more dorsal parts are called alar plate. Basal plate dedicated to motor nuclei, alar plate dedicated to sensory nuclei. Between these two there is a groove= called sulcus limitans. Envision that four fingers are basal plate, and all thmbs are alar plates. As progress through deveopemnt alar plate start to move away from eachother like abook and therefore these dorsal ones will now come all the way lateral |
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Term
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Definition
| We started with the pyramids here , corticospinal tract delving down, if you go lateral we find the olive and inferior olviary nucleus , from this nucleus unstained part the axons will come to form the olivocerebellar joining the inferior cerebellar peduncle betweent eh inferior olvie and pyramids you have one nervining coming out the hypoglossal nerve coming form the hyposglossal nucleus in the dorsal part of the medulla. Just lateral to hypoglossal is the dorsal motor nucleus of X. The preganglionic parasympathetic fiber coming out and innervating the lungs , heart and intenstines . this prengalgionic parasympathetic will joined by fibers orm nuclus amibgioust o providei nenrvatiofn or swallogin and vocalization. FI move more lateral will find the cuneate nuclus and gracillle nucleus htat will give rise to internal arcuate fiber that will make medial lemniscus and ascend into the thalamus, and spinothalamic tract sitting int eh lateral portion. Nucleus solitarus- receiving information for taste from the tongue that is beign brought itno the same nlceus form free nerves, 7,9 , 10 just different parts, plus the caudal aprt will be important for chemoreceptor and baroreceptors |
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Term
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Definition
| is coming formitnernal carotid artery and vertebral artery. Itnernal carotid is anterior circulation and vertebral is posterior . They are in subarachonoid space , surrounded yb CSF |
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Term
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Definition
| Two vertebral arteries come together to form basilar artery, atn pontomedullary junction |
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Term
| vertebral artery branches |
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Definition
| They each give of two branches down forming the anterior spinal artery on the anterior medulla. Anterior spinal artery providing bulodd supply for the pyramids. Vertebral artery also gives off PICA (posterior inferior cerebellarartery) lateral parts fo the medulla are covered by the PCIA. |
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Term
| territories of brainstem arteries |
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Definition
| ASA- midline - pyramids, Medial lemnsicus, hypoglossal nucleus. PICA- Lateral medulla (spinothalamic, solitary nuclus, some dorsal nuculs of X, soem cuneate nuclus and gracicle nucleus.) vERTEBRAL ARTERY- INFERIOR OLIVARY NUCLEUS` |
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Term
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Definition
| Huge numbers of transverse fiers- form the middle cerebellar peduncles |
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Term
| dorsal veiw of cerebellum - with peducnels and origins |
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Definition
| cerebellum removed. Move up form hypoglossal trigone- get to facial colliculus. Accumualtion of al lcereberal peducnels: inferior one through the medulla, middle cerebellar peduncle coming from the pons, superior cerebellar peduncle exiting from the cerebellum |
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Term
| transverse section of pons stained for myelin. |
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Definition
| Axial section of the pons- Ventral side is stained for weigert . Dorsal side you see the fourth ventrice, prominent struciton- huge number of myelinated fiber on sides , middle cerebellar peduncle. Nuclei are less lablled with weigert state. If look at ventral part of axial section, you will see huge amounts of lessl abelled structures- there are the pontine nuclei. From right side will give contralateral fibers into the left middle cerebellar peduncle, the same the other way. Corticospinal tract is now in between pontine nuclei. |
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Term
| Hints to realize you are not at the pontine level |
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Definition
| You will not be seeing the inferiorolvie structure. IT will have characteristic striated shape or structure hwen stained with myelin: misxture of pontine nuclei and pontocerebellar fibers that will be marking the middle cerebellar peduncle |
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Term
| descending pathways in pons down to spine |
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Definition
| corticospinal tract- rostral to caudal – descending, will start in the pons, moved away from the ventral surface, as move more caudally will move out on the surface as pyramids. These pyramids will continue to that pyramidal decussation leel. This corticospinal tract will be splti into lateral coritoc spinal tract sitting in lateral portion of spinal cord and will have oen portion uncrossedt he anterior coritocopspinal tract istting int eh medial portion of the ventral side of the psina lcord. |
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Term
| ascending pathways from spinal cord to pons: DCMLS |
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Definition
| DCMLS pathway- turns and goes up at horn, synaspes at gracile nucleus and cuneate nuclus that will give rise to internal arcuate fibers forming medial lemniscus- which is medially position in medulla. This medial lemniscus has somatotopic organization- the legs are close to the pyramids. IF you go into the pons , medial lemniscus strats to move laterally and leg portion looks like it slipped on a banana, slipping away from the midline. |
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Term
| ascending pathway from spine to pons: STT |
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Definition
| we know that the first newruons in dorsal root ganglion ameks immediate shaspe in spinal cord goes to anteralateral system, it is compeleltely lateral ,faraway form medial lemnisus, as medial lemniscus slips laterally ,th ey will start to come closer together, they start to come togetheri n the pons |
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Term
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Definition
| CRANIAL NERVES function of brainstem. 5,6,7,8. Trigeminal and facial enrve both are mixed. Abducens nerve is part of the motor innercation of extracoccular muscles (covered later). Vestibulocochlear hearing and balance, covered in adifferent lecture. |
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Term
| Trigeminal nerve lcoation |
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Definition
| Trigeminal nerve coming in at middle cerebellar peduncles. There are two portions, one smaller tiny one and one bigger portion. The smaller is the motor part, and the bi gger one is the sensory aprt of the trigeminal nerve |
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Term
| Trigeminal nerve function |
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Definition
| pain/temperature, discrimantive touch and conscious proprioception of anteriot tow thirds of the face and head. |
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Term
| GSa function fo trigeminal nerve |
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Definition
| for pain and temp , discriminativetouch and pressure, and unconscious proprioception for inside Nose and in mouth |
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Term
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Definition
| They provide inenrvatin ofor muscles of mastication (i.e. chin) will be covered by five, and one muscle in inner ear. |
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Term
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Definition
| will be important for sensory information for corena and eye. |
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Term
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Definition
| will be important for upper teeth and outer surface . |
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Term
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Definition
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Term
| nucleus for pain and temperature |
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Definition
| will extend its cell body into medulla and reach the s pinal cord. Spinal nucleus of five- It looks like a s tick- pain and temperature. |
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Term
| trigeminal nucelus for discrimiantive touch and pressure |
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Definition
| principal nucleus of five. in pons |
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Term
| trimgenal nucleus for usncioniosu prorpioception |
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Definition
| mesencephalic nucleus of five- from pons to midbrain. |
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Term
| innervatin for mastication |
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Definition
| principal nucelus of five in the pons. |
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Term
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Definition
| midline positioned opening to cisterns |
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Term
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Definition
| two lateral openings to cisterns |
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Term
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Definition
| from pharynx,larynx, meninges, and region of outer ear. will join nuclusof CN V |
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Term
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Definition
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Term
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Definition
| midline- pyramids, Medial Lemniscus, hypoglosal nucleus |
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Term
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Definition
| lateral medulla- spinothealamic, soltiary ncleus , some dorsal nucleus of xand some cuntea uclus and gracile nucleus |
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Term
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Definition
| Pain and temperature: first order neuron is sitting in the trigeminal ganglion. The peripheral branch is binging painful info itno trigeminal ganglion. The central axon will now enter at the level of middle cerebellar peduncles in the pons. Some of these axons will synapse in the second order neuron in spinal nucleus of five. But some will delve down and make synapses in the medulla and some will go even further making synaspes in the spinal part of the spinal nuclus of five. Once they make these synapses ont ehsecond ordern eruon for pain and temperature in spinal nucleus (the stick) , the 2nd order neruosn give rixsse to axons c rossign to contralateral side, orming the trigemnothalamic pathway. 3rd order neuron- ventral posteromedial nucleus of thalamus. In the thalamus we will have third order neuron similar for spinothalamic tract. The crossing occurs at medullary and pontine levels. They wil le distrubted form pons to medulla into spinal cord. |
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Term
| anatomic relation location of spian lnuclus of f ive (look at cross section |
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Definition
| The posision fo spinal nuclus of V that is bringing pain and temperature for the face. We are in caudal medulla, gracilleadn cuneate nucleus are apparent, if move more latereal we find spinal nuclus of five and spinal tract that is coming from the pons and down ad now making synapses into neurons of the spinal nucleus of five, spinal ucleus of five crosses immediately making trigemnothalamic pathway |
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Term
| anatomic relation location of spian lnuclus of f ive (look at cross section |
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Definition
| The posision fo spinal nuclus of V that is bringing pain and temperature for the face. We are in caudal medulla, gracilleadn cuneate nucleus are apparent, if move more latereal we find spinal nuclus of five and spinal tract that is coming from the pons and down ad now making synapses into neurons of the spinal nucleus of five, spinal ucleus of five crosses immediately making trigemnothalamic pathway |
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Term
| sensory ifno form outer ear |
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Definition
| One portion of7, nine and 10 brinigning sensory ifno from outer ear. All axons from the outer ear will enter at the level fo nine and ten at the medulla but their axons will join this spinal tract of five and make connections in the s inal nucleus of five.7, 9 and 10 will join the five for pain and temp for the otuer ear at this le vel. |
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Term
| spinal nuclues blood supply |
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Definition
| PICA artery covers this part. If have lateral medullary syndrome, the contralateral pain and temp for the body will be lost. Pain and temp for the face is ipsilateral loss. |
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Term
| spinal nucleus of V aptiotemporal relationship |
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Definition
| as go from rostral to caudal along spinal nuclus,you see that wthere is atnerior to psoterior innervation of the face . I.e. more cadually is more psoterior inervaiton of face. |
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Term
| pathway for trigeminolemniscal pathway |
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Definition
| Second sensory modality for the face , that we also know that some of thei fnormaiton from the body are discrimative touch and conscious proprrioceoption. Firstn e ruon for that pathway is in trigeminal ganglia. Same way ,peripheral branch bringing in info . the Central branch is now coming in through middle cerebral peduncles, however these axosn will just end on principel nucleus of five, present in the pons. Neurons in principal nucleus of five will give axons andross immediately to the contralateral side to form the trigeminal lemniscal pathway. So if your emidn yourself what is the anem of het pwathway birnging discriminative touch and conscious propricopetion for the body is the DCMLS pathway, here the same thing trigemnolemnicscal pathway will be formed from the second order neurons from the principal sensory ncluelsu of five and will end up in the same nucleus as trigemnothalamic pathway fro pai and temperature in the VPM. The thing to remember , that most of this tract is crossed nthe pontine , level. |
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Term
| position of principal nuclus of five |
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Definition
| Mainsensory nuclus of five. Look at the level of the pons. Here are the pontine nuclei, corticospinal tract for sensory nuclei we have to go really lateral and here is wherei ti s palcedi nt he most alteral a little bit dorsal portion fo the pons. |
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Term
| mescenephalci nucelus of V: location and funciton |
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Definition
| which extends from the pons in to the imdbrain /mesencephalon. This oone is ringing information of position of head in space. Simliar to dorsal calrkes nucleus in the spinal cord. As it goes / climbs out this mesenphalic nucleus will actually be close to structure known aas superior cerebellar peduncels coming out of cerebellum. This nucleus is one exception to al lsensory pathways in CNS. |
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Term
| mesecnephalic nucleus pathway |
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Definition
| primary neeres ar ethe nucleus , go to several structures, including motor nucleus of V. Test jaw afferent jaw reflex |
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Term
| motor nuclus of five position |
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Definition
| Motor nucleus is very close to primary sensory nuclus of five is stitting. Just motor is more medial and sensnory si morelateral. |
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Term
| innervation for motor nulceus of five |
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Definition
| Corticobulbar pathway at V is bilateral. – msucles of mastication. |
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Definition
CN V lesions- unilateral lesion of trigeminal nerve, will see motor defects- chin deviation in direction of the lesion and atrophy (LMN) (Ipsilaterla innervation)
Oneo f the more common manifestations of the trigeminal lesion. Trigeminal neuralgia- severe pain fro the face triggered by cold, and unusual stimuli. Mostly unkown. Facial sensation is normal. Severe episodes of pain that can last form seconds to minutes. IF test sensation of trigeminal nerve wl lbe completely normal in patient. Other lesions can be most common ones for any central nervous neruons liekrauma and demyelination or motor neuron disease. |
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Definition
| We are at facial nerve, second oen to cover form the pons. If we looked at ventral side, the seen will becoming out in the ponto cerebellar junction. So we are counting from the medial to lateral = 5,6,7 wil lbe this one even thoug hteh nuclei are inside the pons. And when we look dorsal side above the hypoglossal trigone we had the base or floor of the fourth ventricle, the facial colliculus. So it has to do something with the facial nerve. |
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Definition
| Facial nerve is oen of htos ethat has two efferent two motor components. Has both visceral (SVE) that are muscles from different arches than somatic. There is general visceral efferent that are preganglionic parasympathetic that we learned in enrves nine and ten. This guys the muscles from this brain kill arches will be the muscles of facial expression (smile move eyebrows up). GVE , parasympathetic will be covering al l salivary glands but partid (which is covered by cranial nerve IX). Plus lacrimal gland (tearing and salivation is VII). Follows the rule buy two efferent get three afferent. GSA, SVA,GVA. GSA- the oen that will be joining that will bjoing spinal nuclus of five is also part of outer ear. Beside nien and ten seven is also covering that part. The saem thing with taste (SVA), 7,9,10 are coming out a part of the ear plus taste from the tongue. This one is covering anterior two thirds of the tongue. Posterior one third is nine . and eepiglottis is ten. GVA- some mucous membrane of nasopharynx. |
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Term
| facial motor nucelus location and pathway |
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Definition
| Facial motor nucleus- The part will innervate our fascial muscls of expression. The nucleus is found in the pons – rule:2;2;4;4. However, this facial collicluus that we saw at the floor of the fourth ventricle is not formed by the nucleus. Hypoglossal trigone, vagal trigone, They are all having nuclsu just benath it. This tiem story is just a ltitel bit different. The nuclus will be a little bit more ventral. But the fibers , the motor axons will be going back and turn around another nucleus, the abduccens nucleus, and then coming down and exiting in the pontomedullary junction of the lateral side. This fiber accumulation will make this bump or facial colilucus in the base of the fourth ventricle. |
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Term
| innervation for facial motor nucleus |
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Definition
| corticobulbar tract. Coricobulbar inenrvaiton is somatotopically distributed. Upper face and lower face. – inenraetd by differnet parts of facial nuclus. The difference between upper face and lower face: upper face , lower motor neruosn of facial nerve ,will be getting coritcobulbar pathway rom both sides. For the lower face, will be mainly crossed. The right side cortex representation of homonuclus for the face, the coritcobulbar will come own go through thei tnernal capsule come out and innervate the lower part of the face contralatteraly. You can distinguish between UMN and LMN. Since if you have lesion of UMN at the level fo internal capsule . youw ill lose these two corticobulabar tracts coming down. One red one, will be lost for inervatoin of upper face. However Upper face has corticoulaar tract form contralateral side, and therefore upper face will not be effected by lesion from the upper motor neuron. However, the blue one will be cut and not functional, and that one is corssing and innervating the lower part of the face which will be effected. If you have UMNL you will be able to move your e yebrows ,but you will not be able to smile. |
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Term
| LMN lesion of the facial nerve |
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Definition
| Summary- but this case we can focus on the lower motor neuron lesions. If you have al woer motor neuron elsion ,, so facial nerve is ipsilateraly innerating the hwole half of the face. If have a lesion here, both tracts coming from the lower part of the nuceuls and rtracts from the upper part of the nuclus will be cut and therefore the whole part of the face will be effected. |
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Definition
| This is just at able of reflexes that facial nerve is involved in. This is just a table of reflexes that facial nerve is involved in. one called corneal reflex.- will se how two nerves we just rlearned will cooperate. Sensor yinenrvation of cornea is coming form the trigeminal (ophthalmic part). It is goingint o the spinal ncuelus of trigeminal or principal nuclus. Some neurons will go and innervate facial nucleus, that will close the eye . in the corneal reflex, if you use cotton tip and touch the eye, both eyes will close. Fibers form this trigmineal nucli innervate both facial nuclei, bilateral reflex. |
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Term
| facial nerve GVE nuclues , locaiton and function |
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Definition
| There is GVE innervation. Preanglionic parasympathetic fibers. Preganglionic parasympathertic for X for body, from IX for parotid gland. Eveyrthign else producing saliva will be covered by VII. IX we had exception in the rule for htepositioning of the nucleus. It was inferior salivatory nuculs. Here we have superior salivatory nucleus- will be contributing to VII to produce saliva. VII coming out of pontomedullary junction will be giving rise to all salivary plus one lacrimal producing tearing. Fucniton- tearing /salviation by seven. |
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Definition
| Sensory parts. Taste- anterior two thirds is covered by VII going into solitary nucleus. Enter at thel evle of lateral pontomedullary junction and enter into rostral part. Fibers of VII will be joined by IX for anterior third and by X for epiglottis. |
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Definition
| We also said that there is one portion of the ea covered for certain sensory information that will be joined by nien and ten and will be joined by spinal nucleus of five. |
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Definition
| Lesions of VII. = besides motor lesion, one commo0n manifestation is bells palsy. All functions of VII are effected. Motor Lesion: LMN type, patient will nto be labe to move al lthe muscles of the face. And then , you have some retroauricular pain. Plus you will have dry eye because alcrimal gland is effected. Plus loss of taste. Cause: UNK |
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Term
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Definition
| Summary of what we learned. Started with transversal section. We defined pontine nucleus , corticopsinal tract, the pontine nuclei giving rise to axons that will cross and make the middle cerebral peduncle, so when we moved inthsi dorsal part where the nuclei are, we learned about motor nucleus of v sensory nlcues , facial nucleus of V, and some of the pathways and mesenphalic nucleus htat wil lgalso go up. Also, this facial colliculus is formed by the fibers that come from facial nucleus delving around and coming down and out. |
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Definition
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Definition
Blood supply for the pons- internal carotid and vertebral artery. When we awalked up and covered medulla we had vertebral artery forming anteirior spinal artery and vertebral artery giving rise to pica. These two arteries are main ones covering medulla. Middle portion with anterior spinal artery and lateral medullary syndrome caused by occlusion of pica. If you move up you will see htat hetse two vertebral arteries will come together to form basilar artery, this basilar artery will give some paramedium going inside the pons, plus some branches before , bifurcating into posterior cerebral artery. Two branches before that are AICA and Superior cerebellar artery coming close to posterior cerebral.
If you lo kofro malteral side, basilar artery is here formed by two vertebral arteries , you see some paramedium brnaches coming , and the nyou have this l ataeral side of the posn covered by AICA. |
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Term
| arterial terriotires in pons |
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Definition
Here are the territories, we are now familiar with axial section of the pons. Here is the groove hwerfe basilar arteries is sitting , giving rise to this paramedium branches to cover medial portion of the pons. Corticospinal tract is affected by basilar artery (contralateral issues). The most lateral parts are covered by AICA.
There is a pathway descending- conduit function going through all these parts: midbrain pons medulla, descending sympathetic fiber |
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Term
| descending sympathetic pathway |
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Definition
| From hypothalamus these fiber swill be going through midbrain , pons medulla, innervating the intermidiolateral column in the spinal cord. IF you have ischemic insult, within the pons or medulla, you will develop symptoms of sympathetic lesions |
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Definition
| The first one is when yo ucmpare size of htep upils. This is constricted, drooping of eyelids, apparent sinkig of eye ball. Decreased sweating, increased skin temperature. |
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Definition
| Ventral view of the midbrain. Lateral sides we see two prominent structures called cerebral peduncles, here are descending from corticospinal /corticobulbar, and frontopontine- goes from frontal cortex to pontine nuclei around coritocspinal tracts in the pons. Between two cerebral epduncels there is a groove. This space is caleldi tnerpeduncular fossa. Fileld up with CSF, this is third cistern, interpeduncular cistern. We seeo ne nerve coming out and one coming form behind. |
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Term
| cerebral peduncles functions |
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Definition
| conduits for the coritcospinal/cerebrospinal to descend to pontine nuclei |
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Term
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Definition
| Dorsal side of the midbrain. Here is the fourth ventricle. In the midbrain we have the cerebral aqueduct, hidden inside by colliculi. Two of them are superior, others are inferior . Mnemonic- Eyes above ears- superior in vision processing, inferior in auditory processing. Cells from both colliculi are connected with the thalamus, these connections are called brachium. Brachium of superior/inferior colliculus. |
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Term
| transversal seciton of midbrain |
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Definition
| If you make a transversal cut through hteh midbrain and here is the ventral side, you can see small lgroove itnerpundcular fossa. And on the lateral side of this interpeduncular fosas , see huge amount of fibers. This is again myelin stain, myelin fibers will be darkly stained. This is cerebral peduncle. Move dorsally: here is one opening connecting fourth and third ventricle- cerebral aqueduct. Most dorsal we see bulges- the collicliu. |
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Term
| three different portions of braisntem (vetntral to dorsal) |
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Definition
| Best palce to define three different regions of brainstem, can be applied to pons , medulla midbrain. Most ventral are basis of brainstem. Middle parts are called tegmentum, dorsal part are called tectum. |
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Term
| location of corticospinal tract in midbrain and somoatropic organization |
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Definition
| basis pedunculi- Basal part of the midbrain- conduit function of the midbrain. SOmatotopic organization these fibers are descending, leg trunk arm – cotricospinal and face is corticobulbar. Two regions are unlabeleld- the frontal pontine fibers, that wil end on the pontine nuclei in the pons. I |
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Term
| ascendign apthways of mdibrain location |
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Definition
| If we move posterior to cerebral peduncls, and posterolaterally tor ed nucleus, will see ascending apthways. Everything that was coming thorugh medulla nad formed through medulla and pons has to come up and reach thalamus. They are all together here , just because there is a midbrain diencephalon , midbrain thalamic junction , so they are coming closer to reach the nuclei that htye wanna reach. That’s why we have medial lemniscus, spinothalamic , plus two new tracts- trigemnothalamci and trigeminal lemniscus, this pathway go into VPM, and this one will got to VPL. Two eye shaped structures- red nucleus- accumulation fo cell bodies- Nucelus rubber. – Rubrospinal tract. |
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Term
| rubrospinal tract pathway |
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Definition
| Starts inr edn ucleus of midbrain and reaching spinal cord. Crosses eimmediatly in midbrain, joins the corticospinal tract in the lateral part of the spinal cord. Ruborspinal is very closely related to corticospional tract in the spinal cord. INnervation of flexors |
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Term
| tectospinal tract pathway |
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Definition
| Tectospinal tract- Tectum- the most dorsal party where collciuli are. Will start in superior collculus , crossing immediately in midbrain. It will go down into the spinal cord ,but will end up in the cervical spinal cord. Involved in reflexive reaction to light soruce, or coordinated eye/neck movements. |
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Term
| descending pathways of midbrain slide look at it |
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Definition
| Summary of the descending pathways. Form the midbrain all the way down to the spinal cord. Red- corticopspinal and corticobulghbar surrounded by fronto pontine fibers. FI we come to the level of the pons , the frontopontien will start to disappear because wil lsynaspe on to pontine nuclei, these pontien ncueli will give rise to ponotocerebellar fibers. The corticospoinal tract wi lcontineu through the pons and come out as pyramids int eh emdulla that will cross and stay in the lateral column fo the spinal cord. Joiend here shown in yellow is the rubrospinal tract , it will go down and stay closely related to corticospinal tract. |
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Term
| Ascending pathways midbrain summary look at sldie |
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Definition
| Ascending pathways- first neurons are in DR. Red- will be DCMLS. Will come up climb make a synapse in graccile nucleus/cuneate . cross to contraletaral sid e as medial lemnicsucs. In the medulla medial lemniscus will be psoitioend her and wil start sliping in the pons and slip wall the way n the lateral sidei n the midb rain. You can se ehwo this anteroalteral systemi s coming closer and closer to the dorsal columns befoe entering the thalamus. |
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Term
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Definition
| Midbrain cranial nerves: III comes from interpeduncular fossa. All cranial nerves will be emerging and receiving sensory information from ventral side with one exception. – that’s number four. It exists at dorsal side and reaching around cerebral peduncels to go and innervate one extraoccular muscle. |
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Term
| Occulomotor nerve position, pathway, and function. |
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Definition
| If you cut through more rostral part of midbrain we will see besides cerebral peduncle (that have corticobulbar and corticospinal and fronpontine ), besides these sensory fibers (anteroalteral and DCMLS and trigemnothalamic), besides this red nucleus, there will be ancuelsu in the midline positioned like a v shape structure (medial to red nucleus and - This is occulomotor nucleus (nucleus for III). Fibers from this nucleus will basically go through red nucleus and emerge out in interpeducnular fossa. Improtnat thing to remember: besides this inenrvation of muscles for extracocuclar movements , it will also bring parasympathetic fibers to constrict hteh pupils. . Horners syndrome- that’s why pupil is constricted, because pNS fibers for III are dominant. |
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Term
| trochlear nucleus- location and pathway |
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Definition
| Last nerve- caudal levels of midbrain, positions just anterior to cerebral aqueduct.- Trochlear nerve nucleus (axons will come posterior to cross to contralatteral side nad exit out). Will innervate only oen muscle. |
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Term
| exit point for nerves III and iV |
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Definition
Exit point for III between two cerebral peduncles. Exit point for IV below the inferior colliculi. , coming out on dorsal side from contralateral nucleus .
Abducens nerve- 3,4,6 invovledi nexatraoccular movement. |
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Term
| blodo supply to midbrain (ventral and lateral view) |
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Definition
bLodo supply for brain stem – we walked form vertebral aretrie into basilar artery. Basilaerr artery gives rise to Superieor cerebelalr aretery ,after htat splits into posterior cerebral arteries(two of them).
Posterior cerebral artery lateral side is coming off above the spinal cord artery and you can see how it is acutall ygoing around cerebral epduncel , and posterior cerebral artery is beside covering the posterior parrot f the medial cortex (occipital one), will be giving some blood supply for cerebral peduncles in midbrain. |
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Term
| lesion to posterior cerebral artery |
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Definition
| If havel sion of posterior cerebral artery in the proximal part, will be affected almost whole part of the midbrain – that means we will hav e some motor lesions with this coritcospinal/bulbar, you will have mainly sensory lesions affected by ascending pathways. Colliculi – will be covered by superieor cerebellar artery, shared a little with posterioer cerebral artery. Posterior cerebral artery will be covering major part of the midbrain. |
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