====== MEDULLA OBLONGATA ====== * MEDULLA OBLONGATA * Structural Components * Vital center * Cardiac center * Regulates heart rate and force of contraction * 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 * [[:en:fourth_ventricle |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 * proprioceptive impulse to cerebellum * same side * 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 * feet and leg * 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 * Restiform body * 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 * Juxtarestiform body * Restiform body * 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 | |