en:medulla_oblongata

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MEDULLA OBLONGATA

  • MEDULLA OBLONGATA
    • Structural Components
      • Vital center
        • Cardiac center
        • Vasomotor center
          • regulation of distribution of blood flow in vessels
        • Respiratory center
          • regulation of respiration
    • External features
      • ANTERIOR OR VENTRAL
        • divided in to longitudinal halves by
          • Anterior median fissure; ventral median fissure
            • continuous with fissure of spinal cord
              • just above joining ends in a triangular depression
                • Foramen caecum of medulla oblongata
            • at lower border of pons
              • interrupted by decussation of pyramids
        • Two elongated elevations on each half called as
          • Pyramids
            • caused by corticospinal ( pyramidal) fibers
              • most of these fibers cross to opposite side in lower medulla
                • Decussation of pyramids; motor decussation
                • descend as lateral corticospinal tract
                  • in lateral white column
              • uncrossed fibers descend as
                • anterior corticospinal tract
                  • in anterior white column
        • Oval elevations called
          • Olive
            • caused by inferior olivary nucleus
      • LATERAL OR SIDES
        • divided in to longitudinal halves by
          • ANTEROLATERAL SIDES
            • Anterolateral sulcus; ventrolateral sulcus
              • extends along lateral border of pyramid
              • XII - rootlets of Hypoglossal nerve emerges
          • POSTEROLATERAL SIDES
            • Posterolateral sulcus; dorsolateral sulcus
              • lies between olive and inferior cerebellar peduncle
              • emerges from it are
                • IX , X , XI cranial nerves
            • Inferior cerebellar peduncle
              • posterolateral to olive
              • attach medulla with cerebellum
      • DORSAL OR POSTERIOR
        • divided in to longitudinal halves by
          • Posterior median sulcus; dorsal median sulcus
            • present only in lower half of medulla
            • above it lips diverge to form
              • boundaries of triangular area
              • lower part of 4th ventricle
        • Upper Open part
          • FOURTH VENTRICLE
          • Posterior median sulcus; dorsal median sulcus
            • either side of sulcus
          • more laterally and obliquely continuation of sulcus limitans of pons
            • from stria medullares
              • sulcus limitans converges towards the upper end of lower medulla
            • depression at sides on sulcus limitans
              • inferior fovea
            • it divides it in to two areas
              • hypoglossal triangle
              • vagal triangle
            • between vagal triangle and gracile tubercle
              • area postrema
                • function as chemoreceptor
              • ependymal thickening
                • funiculus separans
                  • separates both vagal triangle and area postrema
            • lowermost point is called obex
        • Lower Closed Part
          • either side of sulcus
            • 3 longitudinal elevations ( medial to lateral )
              • fasciculus gracilis
                • upper end expand to form gracile tubercle due to
                  • nucleus gracilis
              • fasciculus cuneatus
                • upper end expand to form cuneate tubercle due to
                  • nucleus cuneatus
              • Tuber cinerum
                • caused by spinal nucleus of trigeminal nerve
              • inferior cerebellar peduncle
    • INTERNAL FEATURES OF MEDULLA
      • At the level of decussation of pyramids
        • POSTERIORLY
          • narrow strips nucleus gracilis and nucleus cuneatus
          • posterior horn
            • apex gets swollen to form
              • nucleus of spinal tract of trigeminal nerve
                • it is upward continuation of substantia gelatinosa of spinal cord
          • posterior horn capped in white matter by
            • fibers of spinal tract of trigeminal nerve
          • runs backwards and laterally across midline ( from anterior to posterior )
            • to reach lateral side
        • ANTERIORLY
          • detached anterior horn divides to form
            • spinal nucleus of accessory nerve
            • supraspinal nucleus of first cervical nerve
              • continuous above with hypoglossal nucleus
            • nucleus of accessory nerve
              • extends downwards up to 5th cervical segment
        • LATERALLY
          • in white column diffused network of fibers
            • reticular formation
      • At the level of decussation of medial lemnisci ( or Sensory decussation )
        • ANTERIORLY
          • lower part of inferior olivary nucleus
          • pyramid
        • POSTERIORLY
          • posterior white column
            • fibers of fasciculus gracilis and cuneatus
          • nucleus gracilis and nucleus cuneatus are well seen and demarcated
            • separated from central grey matter
        • CENTRALLY
          • central grey matter contains
            • ventromedial
              • hypoglossal nucleus
                • dorsolateral
                  • dorsal nucleus of vagus
                    • dorsolateral
                      • nucleus of tractus solitarius
        • SIDES
          • Dorsolateral to cuneate nucleus
            • accessory cuneate nucleus
              • receives lateral fibers (derived from cervical segments of cord ) of fasciculus cuneatus
                • gives rise to posterior external arcuate fibres
                  • through inferior cerebellar peduncle
            • spinal nucleus and tract of trigeminal nerve lies laterally side of cuneate nucleus
          • Ventrolateral
            • medial longitudinal bundle lies posterior to medial lemniscus
            • spinocerebellar and lateral spinothalamic tract
        • SENSORY DECUSSATION (POSTERIOR TO ANTERIOR )
          • Arising from nucleus gracilis and cuneatus
            • internal arcuate fibers
              • course forward and medially around central grey matter
                • decussate with opposite fibers in median plane
                  • ascend upwards as MEDIAL LEMNISCUS on opposite side
                    • most medial fibers come to lie anteriorly
                  • relay in to the thalamus
      • At the level of Olives ( across the floor of fourth ventricle )
        • central grey matter is spread and broken
          • over floor of fourth ventricle
          • medial to lateral
            • posteriorly
              • hypoglossal nucleus
              • nucleus intermedius
              • dorsal nucleus of vagus
              • vestibular nucleus
            • middle or intermediate
              • nucleus ambiguus
                • gives origin to 9 , 10 , 11
          • paramedian region ( either side of midline - from posterior to anterior)
            • median longitudinal fasciculus
            • tectospinal tract
            • medial lemniscus
            • corticospinal tract
        • laterally
          • dorsal to ventral
            • inferior cerebellar peduncle
            • dorsal accessory olivary nucleus
            • medial accessory olivary nucleus
            • inferior olivary nucleus
          • anteromedially
            • arcuate nuclei
      • At the level just inferior to pons
        • lateral vestibular nucleus replaces inferior vestibular nucleus
        • cochlear nucleus
  • MYELENCEPHALON; MEDULLA OBLONGATA; BULB
    • Pre-olivary groove
    • Lateral funiculus
    • Inferior olive
    • Anterior external arcuate fibres; ventral external arcuate fibres
    • Retro-olivary groove
    • Retro-olivary area
    • Inferior cerebellar peduncle
    • Trigeminal tubercle
    • Cuneate fasciculus Budach
    • Cuneate tubercle
    • Gracile fasciculus Goll
    • Gracile tubercle
    • Obex
    • White substance
      • Pyramidal tract
        • Corticospinal fibres
        • Bulbar corticonuclear fibres
        • Corticoreticular fibres
    • Decussation of pyramids; motor decussation
    • Gracile fasciculus Goll
    • Cuneate fasciculus Budach
    • Internal arcuate fibres
    • Decussation of medial lemniscus; sensory decussation
    • Medial lemniscus
    • Tectospinal tract
    • Medial longitudinal fasciculus
    • Posterior longitudinal fasciculus; dorsal longitudinal fasciculus Schütz
    • Spinal tract of trigeminal nerve
    • Amiculum of olive
    • Spino-olivary tract Helweg
    • Olivocerebellar tract
    • Inferior cerebellar peduncle
    • Solitary tract
    • Anterior external arcuate fibres; ventral external arcuate fibres
    • Posterior external arcuate fibres; dorsal external arcuate fibres
    • Raphe of medulla oblongata
    • Anterior raphespinal tract
    • Anterior reticulospinal tract; ventral reticulospinal tract
    • Anterior spinocerebellar tract; ventral spinocerebellar tract Gowers
    • Hypothalamospinal fibres
    • Interstitiospinal tract
    • Lateral raphespinal tract
    • Lateral bulboreticulospinal tract
      • Medullary reticulospinal fibres
    • Lateral vestibulospinal tract
    • Posterior spinocerebellar tract; dorsal spinocerebellar tract Flechsig
    • Cuneocerebellar fibres
    • Rubrobulbar tract
    • Rubro-olivary tract
    • Rubrospinal tract Monakow
    • Spinal lemniscus; anterolateral tracts; anterolateral system
      • Spinothalamic fibres
      • Spinoreticular fibres
      • Spinomesencephalic fibres
        • Spinotectal fibres
        • Spinoperiaqueductal fibres
      • Spinohypothalamic fibres
      • Spinobulbar fibres
        • Spino-olivary fibres
    • Spinovestibular tract
    • Tectobulbar tract
    • Grey substance
      • Gracile nucleus
        • Central part; cell nest region
        • Rostral part; shell region
        • Rostrodorsal subnucleus; cell group z
      • Cuneate nucleus
        • Central part; cell nest region
        • Rostral part; shell region
      • Accessory cuneate nucleus Monakow
      • Preaccessory cuneate nucleus; cell group x
      • Spinal nucleus of trigeminal nerve
        • Caudal part
          • Zonal subnucleus
          • Gelatinous sugnucleus
          • Mergocellular subnucleus
        • Interpolar part
      • Retrotrigeminal nucleus
      • Retrofacial nucleus
      • Inferior olivary complex
        • Principal olivary nucleus
          • Dorsal lamella
          • Ventral lamella
          • Lateral lamella
        • Hilum of inferior olivary nucleus
        • Posterior accessory olivary nucleus; dorsal accessory olivary nucleus
        • Medial accessory olivary nucleus
      • Nucleus of hypoglossal nerve
      • Posterior paramedian nucleus; dorsal paramedian nucleus
      • Posterior nucleus of vagus nerve; dorsal nucleus of vagus nerve
      • Nuclei of solitary tract; solitary nuclei
        • Parasolitary nucleus
        • Commissural nucleus
        • Gelatinous solitary nucleus
        • Intermediate solitary nucleus
        • Interstitial solitary nucleus
        • Medial solitary nucleus
        • Paracommissural solitary nucleus
        • Posterior solitary nucleus; dorsal solitary nucleus
        • Posterolateral solitary nucleus; dorsolateral solitary nucleus
        • Anterior solitary nucleus; ventral solitary nucleus
        • Anterolateral solitary nucleus; ventrolateral solitary nucleus
      • Vestibular nuclei
        • Inferior vestibular nucleus
          • Magnocellular part of inferior vestibular nucleus; cell group f
        • Medial vestibular nucleus Schwalbe
      • Marginal nucleus of restiform body; cell group y
      • Cochlear nuclei
        • Posterior cochlear nucleus; dorsal cochlear nucleus
        • Anterior cochlear nucleus; ventral cochlear nucleus
          • Anterior part
          • Posterior part
      • Commissural nucleus of vagus nerve
      • Nucleus ambiguus
      • Retro-ambiguus nucleus
      • Inferior salivatory nucleus
      • Arcuate nucleus
      • Raphe nuclei
      • Area postrema
      • Endolemniscal nucleus
      • Medial pericuneate nucleus
      • Lateral pericuneate nucleus
      • Perihypoglossal nuclei
        • Subhypoglossal nucleus Roller
        • Intercalated nucleus Staderini
        • Prepositus nucleus
      • Peritrigeminal nucleus
      • Pontobulbar nucleus
      • Supraspinal nucleus
      • Reticular nuclei
        • Gigantocellular reticular nucleus
          • Pars alpha
        • Anterior gigantocellular reticular nucleus; ventral gigantocellular reticular nucleus
        • Lateral paragigantocellular reticular nucleus
        • Interfascicullar nucleus of hypoglossal nerve
        • Intermediate reticular nucleus
        • Lateral reticular nucleus
          • Magnocellular part
          • Parvocellular part
          • Subtrigeminal part
        • Parvocellular reticular nucleus
        • Posterior paragigantocellular reticular nucleus; dorsal paragigantocellular reticular nucleus
        • Central reticular nucleus
          • Dorsal part
          • Ventral part
        • Medial reticular nucleus
      • Raphe nuclei
        • Obscurus raphe nucleus
        • Pallidal raphe nucleus
        • Magnus raphe nucleus
208 MYELENCEPHALON; MEDULLA OBLONGATA; BULBUS MYELENCEPHALON; MEDULLA OBLONGATA; BULB
209 Fissura mediana anterior Anterior median fissure; ventral median fissure
210 Foramen caecum medullae oblongatae Foramen caecum of medulla oblongata
211 Pyramis medullae oblongatae; pyramis bulbi Pyramid
212 Decussatio pyramidum Decussation of pyramids; motor decussation
213 Sulcus anterolateralis Anterolateral sulcus; ventrolateral sulcus
214 Sulcus preolivaris Pre-olivary groove
215 Funiculus lateralis Lateral funiculus
216 Oliva Inferior olive
217 Fibrae arcuatae externae anteriores Anterior external arcuate fibres; ventral external arcuate fibres
218 Sulcus retroolivaris Retro-olivary groove
219 Area retroolivaris Retro-olivary area
220 Sulcus posterolateralis Posterolateral sulcus; dorsolateral sulcus
221 Pedunculus cerebellaris inferior Inferior cerebellar peduncle
222 Corpus restiforme Restiform body
223 Tuberculum trigeminale Trigeminal tubercle
224 Fasciculus cuneatus Budach Cuneate fasciculus Budach
225 Tuberculum cuneatum Cuneate tubercle
226 Fasciculus gracilis Goll Gracile fasciculus Goll
227 Tuberculum gracile Gracile tubercle
228 Sulcus medianus posterior Posterior median sulcus; dorsal median sulcus
229 Obex Obex
230 Substantia alba White substance
231 Tractus pyramidalis Pyramidal tract
232 Fibrae corticospinales Corticospinal fibres
233 Fibrae corticonucleares bulbi Bulbar corticonuclear fibres
234 Fibrae corticoreticulares Corticoreticular fibres
235 Decussatio pyramidum Decussation of pyramids; motor decussation
236 Fasciculus gracilis Goll Gracile fasciculus Goll
237 Fasciculus cuneatus Budach Cuneate fasciculus Budach
238 Fibrae arcuatae internae Internal arcuate fibres
239 Decussatio lemnisci medialis Decussation of medial lemniscus; sensory decussation
240 Lemniscus medialis Medial lemniscus
241 Tractus tectospinalis Tectospinal tract
242 Fasciculus longitudinalis medialis Medial longitudinal fasciculus
243 Fasciculus longitudinalis posterior; fasciculus longitudinalis dorsalis Schütz Posterior longitudinal fasciculus; dorsal longitudinal fasciculus Schütz
244 Tractus spinalis nervi trigemini Spinal tract of trigeminal nerve
245 Amiculum olivare Amiculum of olive
246 Tractus spinoolivaris Helweg Spino-olivary tract Helweg
247 Tractus olivocerebellaris Olivocerebellar tract
248 Pedunculus cerebellaris inferior Inferior cerebellar peduncle
249 Corpus juxtarestiforme Juxtarestiform body
250 Corpus restiforme Restiform body
251 Tractus solitarius Solitary tract
252 Fibrae arcuatae externae anteriores Anterior external arcuate fibres; ventral external arcuate fibres
253 Fibrae arcuatae externae posteriores Posterior external arcuate fibres; dorsal external arcuate fibres
254 Raphe medullae oblongatae Raphe of medulla oblongata
255 Tractus raphespinalis anterior Anterior raphespinal tract
256 Tractus reticulospinalis anterior Anterior reticulospinal tract; ventral reticulospinal tract
257 Tractus spinocerebellaris anterior Gowers Anterior spinocerebellar tract; ventral spinocerebellar tract Gowers
258 Fibrae hypothalamospinales Hypothalamospinal fibres
259 Tractus interstitiospinalis Interstitiospinal tract
260 Tractus raphespinalis lateralis Lateral raphespinal tract
261 Tractus bulboreticulospinalis lateralis Lateral bulboreticulospinal tract
262 Fibrae medulloreticulospinales Medullary reticulospinal fibres
263 Tractus vestibulospinalis lateralis Lateral vestibulospinal tract
264 Tractus spinocerebellaris posterior Flechsig Posterior spinocerebellar tract; dorsal spinocerebellar tract Flechsig
265 Fibrae cuneocerebellares Cuneocerebellar fibres
266 Tractus rubrobulbaris Rubrobulbar tract
267 Tractus rubroolivaris Rubro-olivary tract
268 Tractus rubrospinalis Monakow Rubrospinal tract Monakow
269 Lemniscus spinalis; tractus anterolaterales Spinal lemniscus; anterolateral tracts; anterolateral system
270 Fibrae spinothalamicae Spinothalamic fibres
271 Fibrae spinoreticulares Spinoreticular fibres
272 Fibrae spinomesencephalicae Spinomesencephalic fibres
273 Fibrae spinotectales Spinotectal fibres
274 Fibrae spinoperiaqueductales Spinoperiaqueductal fibres
275 Fibrae spinohypothalamicae Spinohypothalamic fibres
276 Fibrae spinobulbares Spinobulbar fibres
277 Fibrae spinoolivares Spino-olivary fibres
278 Tractus spinovestibularis Spinovestibular tract
279 Tractus tectobulbaris Tectobulbar tract
280 Substantia grisea Grey substance
281 Nucleus gracilis Gracile nucleus
282 Pars centralis Central part; cell nest region
283 Pars rostralis Rostral part; shell region
284 Subnucleus rostrodorsalis Rostrodorsal subnucleus; cell group z
285 Nucleus cuneatus Cuneate nucleus
286 Pars centralis Central part; cell nest region
287 Pars rostralis Rostral part; shell region
288 Nucleus cuneatus accessorius Monakow Accessory cuneate nucleus Monakow
289 Nucleus precuneatus accessorius Preaccessory cuneate nucleus; cell group x
290 Nucleus spinalis nervi trigemini Spinal nucleus of trigeminal nerve
291 Pars caudalis Caudal part
292 Subnucleus zonalis Zonal subnucleus
293 Subnucleus gelatinosus Gelatinous sugnucleus
294 Subnucleus magnocellularis Mergocellular subnucleus
295 Pars interpolaris Interpolar part
296 Nucleus retrotrigeminalis Retrotrigeminal nucleus
297 Nucleus retrofacialis Retrofacial nucleus
298 Complexus olivaris inferior; nuclei olivares inferiores Inferior olivary complex
299 Nucleus olivaris principalis Principal olivary nucleus
300 Lamella posterior Dorsal lamella
301 Lamella anterior Ventral lamella
302 Lamella lateralis Lateral lamella
303 Hilum nuclei olivaris inferioris Hilum of inferior olivary nucleus
304 Nucleus olivaris accessorius posterior Posterior accessory olivary nucleus; dorsal accessory olivary nucleus
305 Nucleus olivaris accessorius medialis Medial accessory olivary nucleus
306 Nucleus nervi hypoglossi Nucleus of hypoglossal nerve
307 Nucleus paramedianus posterior Posterior paramedian nucleus; dorsal paramedian nucleus
308 Nucleus posterior nervi vagi; nucleus dorsalis nervi vagi Posterior nucleus of vagus nerve; dorsal nucleus of vagus nerve
309 Nuclei tractus solitarii Nuclei of solitary tract; solitary nuclei
310 Nucleus parasolitarius Parasolitary nucleus
311 Nucleus commissuralis Commissural nucleus
312 Nucleus gelatinosus solitarius Gelatinous solitary nucleus
313 Nucleus intermedius solitarius Intermediate solitary nucleus
314 Nucleus interstitialis solitarius Interstitial solitary nucleus
315 Nucleus medialis solitarius Medial solitary nucleus
316 Nucleus paracommissuralis solitarius Paracommissural solitary nucleus
317 Nucleus solitarius posterior Posterior solitary nucleus; dorsal solitary nucleus
318 Nucleus solitarius posterolateralis Posterolateral solitary nucleus; dorsolateral solitary nucleus
319 Nucleus solitarius anterior Anterior solitary nucleus; ventral solitary nucleus
320 Nucleus solitarius anterolateralis Anterolateral solitary nucleus; ventrolateral solitary nucleus
321 Nuclei vestibulares Vestibular nuclei
322 Nucleus vestibularis inferior Inferior vestibular nucleus
323 Pars magnocellularis nuclei vestibularis inferioris Magnocellular part of inferior vestibular nucleus; cell group f
324 Nucleus vestibularis medialis Schwalbe Medial vestibular nucleus Schwalbe
325 Nucleus marginalis corporis restiformis Marginal nucleus of restiform body; cell group y
326 Nuclei cochleares Cochlear nuclei
327 Nucleus cochlearis posterior Posterior cochlear nucleus; dorsal cochlear nucleus
328 Nucleus cochlearis anterior Anterior cochlear nucleus; ventral cochlear nucleus
329 Pars anterior Anterior part
330 Pars posterior Posterior part
331 Nucleus commissuralis nervi vagi Commissural nucleus of vagus nerve
332 Nucleus ambiguus Nucleus ambiguus
333 Nucleus retroambiguus Retro-ambiguus nucleus
334 Nucleus salivatorius inferior Inferior salivatory nucleus
335 Nucleus arcuatus Arcuate nucleus
336 Nuclei raphes Raphe nuclei
337 Area postrema Area postrema
338 Nucleus endolemniscalis Endolemniscal nucleus
339 Nucleus pericuneatus medialis Medial pericuneate nucleus
340 Nucleus pericuneatus lateralis Lateral pericuneate nucleus
341 Nuclei perihypoglossales Perihypoglossal nuclei
342 Nucleus subhypoglossalis Roller Subhypoglossal nucleus Roller
343 Nucleus intercalatus Staderini Intercalated nucleus Staderini
344 Nucleus prepositus Prepositus nucleus
345 Nucleus peritrigeminalis Peritrigeminal nucleus
346 Nucleus pontobulbaris Pontobulbar nucleus
347 Nucleus supraspinalis Supraspinal nucleus
348 Nuclei reticulares Reticular nuclei
349 Nucleus gigantocellularis Gigantocellular reticular nucleus
350 Pars alpha Pars alpha
351 Nucleus gigantocellularis anterior Anterior gigantocellular reticular nucleus; ventral gigantocellular reticular nucleus
352 Nucleus paragigantocellularis lateralis Lateral paragigantocellular reticular nucleus
353 Nucleus interfascicularis nervi hypoglossi Interfascicullar nucleus of hypoglossal nerve
354 Nucleus reticularis intermedius Intermediate reticular nucleus
355 Nucleus reticularis lateralis Lateral reticular nucleus
356 Pars magnocellularis Magnocellular part
357 Pars parvocellularis Parvocellular part
358 Pars subtrigeminalis Subtrigeminal part
359 Nucleus reticularis parvocellularis Parvocellular reticular nucleus
360 Nucleus paragigantocellularis posterior Posterior paragigantocellular reticular nucleus; dorsal paragigantocellular reticular nucleus
361 Nucleus reticularis centralis Central reticular nucleus
362 Pars dorsalis Dorsal part
363 Pars ventralis Ventral part
364 Nucleus reticularis medialis Medial reticular nucleus
365 Nuclei raphes Raphe nuclei
366 Nucleus raphes obscurus Obscurus raphe nucleus
367 Nucleus raphe pallidus Pallidal raphe nucleus
368 Nucleus raphe magnus Magnus raphe nucleus

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  • en/medulla_oblongata.txt
  • 2023/06/23 05:08
  • brahmantra