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...ellar primordium in width and height deepens the groove between it and the mesencephalon. A well-pronounced isthmus rhombencephali is evident. The mesencephalon still comprises two parts, and the button-like formation visible in stage 1

...Hween-brain (Fig. 232, /). The middle vesicle is bodily converted into the mesencephalon or mid-brain (m), but the posterior vesicle differentiates so that three pa h, Hemisphere; i, isthmus; m, mesencephalon; mf, mid-brain flexure; mt, metencephalon ; myl, myelencephalon; nf, nape f

*Midbrain/Mesencephalon *Mesencephalon: undivided

...-brain, mid-brain, and hind-brain, or more technically, as prosencephalon^ mesencephalon^ and rhombencephalon. The prosencephalon is the broadest of the three divis ...om the rhombencephalon which lies posterior to it. In this early stage the mesencephalon shows no indication of local specialization presaging the formation of spec

...ayer. The sulcus limitans proceeds from the rhombencephalon throughout the mesencephalon. In the midbrain two parts can still be distinguished; the marginal layer c ...n subdivisions of the brain, it has been seen that (l) the prosencephalon, mesencephalon, and rhombencephalon can be distinguished as regions in the completely open

Because the mesencephalon is the site of a remarkable series of changes in the shape of the brain in

The outlines between the mesencephalon, thalamencephalon and prosencephalon are easily made out, and correspond cl ...a group of neuroblasts forming the ventral part of the mantle layer in the mesencephalon. These neuroblasts converge to form small rootlets which pass through the g

...ephalon) is characterized by the outgrowing optic vesicles. The mid-brain (mesencephalon) is a simple dilatation. The elongate hind-brain (rhombencephalon) graduall ...tion is thus just caudad of the first aortic arches. The caudal end of the mesencephalon is the portion of the neural tube showing; it is thick walled, with an oval

...He further states that transverse divisions, such as the diencephalon and mesencephalon, are not ' natural regions' because the primary metamerism has ceased to be ...ds between the fourth and third ventricles, "and Bensley ('10) writes: The mesencephalon is noteworthy in a mammal as lacking a ventricle. Its cavity is a narrow ca

...al corrugations appear in the region representing the diencephalon and the mesencephalon; and the same number appear anterior to the occipital somite. The fact that

...he medulla oblongata, another group begins to be laid down in front of the mesencephalon. FiberS from this source descend to the lower part of the brain stem withou ...Fig. 64) decerebrated by sectioning the brain at the rostral border of the mesencephalon.39 The increase in muscle tonus under asphyxial conditions may be interpret

...o primary right and left halves, a floor-plate is lacking, as such, in the mesencephalon and diencephalon. The floor-plate would then be recognized as extending thr ...divided the brain into epichordal and prechordal parts,3 but includes the mesencephalon in the epichordal brain, and the reason for this is obvious; to the midbrai

...s System of Vertebrates (1907) 16|Chapter XVI. Centers of Correlation. The Mesencephalon and Diencephalon]] 127. Outline transverse sections through the mesencephalon of a cyclostome, a 'selachian, a ganoid, a bony fish, an amphibian and a ma

...segment of the posterior cerebral artery (PCA), reflecting flexure of the mesencephalon and diencephalon at this stage. Variations were observed in 17 of 20 sample

...xure of the floor between the mid-brain and the hind-brain. The floor of the mesencephalon is thickened at its cephalic end. The trigeminal ganglion is present as a d

...vestibular part. The sulcus limitans terminates at the rostral end of the mesencephalon and hence does not continue into the diencephalon. Several afferent tracts

...by the third cranial nerve — which is the motor nerve of that segment. The mesencephalon (crura cerebri) contains the corresponding segment of the neural tube. The # The walls of the 3rd ventricle (thalamencephalon) and mid-brain (mesencephalon), in which the terminal nuclei of the optic fibres are developed.

...goes to the corpus interpedunculare and adjacent nuclei in the base of the mesencephalon, from which further connections with motor nuclei are made. See Figure 101

127. Outline transverse sections through the mesencephalon of a cyclostome, a 'selachian, a ganoid, a bony fish, an amphibian and a ma

...ruction of the configurations of the nuclei forming the medial wall of the mesencephalon and diencephalon and the medial external wall of the anterior portion of th ...but thicker in the mesencephalon and diencephalon. The floor plates of the mesencephalon and rhombencephalon show their characteristic thickening and the pontine fl

3. The Oculomotor Nerve originates from n^ ^ in t the mesencephalon (Fig. 339 B). The fibers em( * small iaes ventral surface of the mid-brain ...om 1 the chief motor nucleus, a line of cells extending cranially into the mesencephalon . constitutes a second source of origin for motor fibers. In the adult, the

...ally a bidirectional process: it continues from the rhombencephalon to the mesencephalon and proceeds from the optic chiasma toward the roof of D1, thereby forming The most uncertain part to identify precisely is the mesencephalon (tectum and tegmentum in fig. 11-9) because its delineation toward both the

...halon) is characU'lizt-d by the outttrowing optic \esicies. The mid-brain (mesencephalon) is uinlilTrn-tiliattxl. The hind-briiiti (rhonil>eiicephalon') is elongate mesencephalon which is here thick walled undifferentiated mescnchynie in the sectioi by t

** Mesencephalon ...n plates 1 and 4, By the cephalic flexure (Flexxeph.) which occurs in the mesencephalon (Mesen.) the fore-brain is bent at an acute angle to the hindbrain. The ce

...teriorly. The brain shows very distinctly the three parts, prosencephalon, mesencephalon, and rhombencephalon, separated by grooves (Plate I.). There is no demarcat

...sencephalon|prosencephalon]]) - [[M#midbrain|midbrain]] ([[M#mesencephalon|mesencephalon]]) - [[H#hindbrain|hindbrain]] ([[R#rhombencephalon|rhombencephalon]])

...nsidered as internal marks of the isthmus (Herrick) or are assigned to the mesencephalon (Neal) as their position seems to indicate, need not be discussed here. At ...eing the complexity of ventricular grooves present in the diencephalon and mesencephalon, I would not be willing to say that this slender ependymal groove throughou

...ges, fissura rhombo-mesencephalica lies where the thin" caudal wall of the Mesencephalon passes into the Valvula cerebelli, the boundary between the Mes- and Metenc

(4) Cerebral aqueduct (of Sylvius). The mid-brain (mesencephalon) remains undivided; its primitive cavity becomes this narrow canal connecti d. Mesencephalon. This is the least-modified portion of the primitive brain tube.

...prosencephalon is the diencephalon. Very little change has occurred in the mesencephalon. Hardly any expansion occurs in the region between the hindbrain and the mi 10 Dorsal -View of late fifteen-day embryo. X 10. MC, mesencephalon; H0, rhombencephalon; V17, vitelline vein.

.... Fl., Cranial flexure. D. C, Duct of Cuvier. Dienc, Diencephalon. Mesenc, Mesencephalon. Metenc, Metencephalon. Myelenc. 1, and 2, Anterior and posterior divisions ===The Mesencephalon===

...om their anterior end, in about the position in which the division between mesencephalon and rhomhencephalon will develop later. Towards their anterior end the fold ...cephalon and rhombencephalon are marked off by definite constrictions-—tl1e mesencephalon being particularly prominent at the bend of the head. The greater part of t

...s being centrifugal, these arising in connection with the diencephalon and mesencephalon.

...ies the forebrain and arises from neural crest cells derived from midbrain(mesencephalon) and forebrain(prosencephalon)<ref name="PMID21882426">Treloar HB, Miller A - 5 to 10 somite stage: Anterior portion of the mesencephalon continued producing crest cells for migration to the frontonasal mass.<ref

...ociate the future history of the prosencephalon with that of the nose, the mesencephalon with that of the eye, and the rhombencephalon with that of the ear. ...nial nerves depart. The third and fourth cranial nerves originate from the mesencephalon. Its cavity is the mesocoel (or aqueduct).

...ens in which the brain has been cut through from the rostral border of the mesencephalon to the rostral border of the pons. When the level of the transection passes

:ventricle of mesencephalon (mesocoel) becomes aqueduct of Sylvius, connecting with cavities of optic l :caudal region of brain which later forms mesencephalon and rhombencephalon.

and the mesencephalon. It is, probably, that portion of the crest which will be

mesencephalon. In mammals it contributes fibers to the dorsal longitudinal fasciculus of

mesencephalon by a deep groove. Broad in front and in the region of the optic ...iately behind it. In marked contrast to this is the much longer and larger mesencephalon of the Robert Meyer embryo, as modeled by Thompson'^ Somewhat similar to it

* '''β-catenin is required in the neural crest and mesencephalon for pituitary gland organogenesis'''{{#pmid:27184910|PMID27184910}} "The pi

...e cerebellum which projects into and largely fills up the ventricle of the mesencephalon, the valvula cerebelli. In selachians no valvula is present. The cerebellum

...ventralis cephalica; Me., mesencephalon; P, pharynx; PI. mc, plexus on the mesencephalon. ...orta with the v. cardinalis lateralis and which will form an artery of the mesencephalon but were not injected because they are still solid; A. si., a. subintestina

...continued into the tectal commissure. The curious fold of the roof of the mesencephalon in the cephalad direction which includes the mesocoelic recess occurs very

...tricle, continuous with a deeper groove in the wall of the cord and of the mesencephalon. ...brain, due in part to the acceleration in growth of the diencephalon. The mesencephalon is separated from the rhombencephalon by a marked constriction of the total

...of somites, cp, Posterior limit of prosencephalon; fr, posterior limit of mesencephalon; ps, primitive streak; u, first somite; 1-11, neuromeres. ...encephalon, or bet ween- brain. Then following the undivided mid-brain, or mesencephalon, come the two divisions of the primary hind-brain, or rhombencephalon; the

====II. Mesencephalon==== ...7, B, C). In the case of the 24.—somite embryo of Johnson (’17), both the ‘mesencephalon’ and a segment in front of it without any name (his fig. 1, pl. 2) probab

...ain, the persisting portion of which is the diencepkalon. The mid-brain or mesencephalon, located at the cephalic flexure, is not subdivided. The hindbrain, or rhom

of the mesencephalon. In cyclostomes the middle part of the mesencephalic tectum is a membranous

Prosencephalon or Fore-brain. Mesencephalon or Mid-brain. Rhombencephalon or Hind-brain. ...ephalon are the telencephalon and he thalamencephalon or diencephalon; the mesencephalon remains mdivided; and the subdivisions of the rhombencephalon are the metnc

...alon|telencephalon]] - [[D#diencephalon|diencephalon]] - [[M#mesencephalon|mesencephalon]] - [[M#metencephalon|metencephalon]] - [[M#myelencephalon|myelencephalon]]

...the midbrain in ‘DuGa.’ Associated, no doubt, with the rapid growth of the mesencephalon is the more obtuse cranial flexure in this specimen. figure 4 shows the ne

...nnerer Kleinhirnwulst of Hochsetter) is present as a clear thickening. The mesencephalon now possesses an intermediate layer throughout most of its extent. The post

...tuberculum posterius behind the dorsal thickening, marks the limit between mesencephalon and the primary hind-brain or rhombencephalon. The beginning of the rhomben ...ral hemispheres (tekncephalori) and the between-brain (diencephalon) : the mesencephalon forms the region of the optic lobes and chiasma: the rhombencephalon forms

...s or Eclm'dua,'instead of in the rabbit (Lmus). The lateral surface of the mesencephalon or tegmentum is directly continuous with the large swelling of the tubcmulu ...uintvl, that is, in the deep groove which separates this swelling from the mesencephalon. But, in order to reach the surface, it proceeds around the mesial border o

...other constriction appears marking the posterior limit of the mid-brain or mesencephalon. The third section of the brain, the hind-brain or rhombencephalon is much ....FL, cranial flexure; D.C., ductus Cuvieri; Dienc., diencephalon; Mesenc., mesencephalon; Metenc., metencephalon; Myelenc. 1, and 2, anterior and posterior division

...ars later the epiphysis. The other two (iv and v) obviously enter into the mesencephalon. In se1achians these two segments have connected with them respectively the Herrick’s revision of the nomenclature of the diencephalon and mesencephalon contains two new terms, ophthalmencephalon, and medithalamus. As a pedogogi

The mid-brain or mesencephalon is tubular and curves on itself to join the isthmus. Viewed from the latera

Fibres in central grey of mesencephalon yO

...he end of a small blunt needle. Care must be exercised in working over the mesencephalon and telencephalon of the brain not to injure the brain wall, which may be b

...medulla oblongata is developed. Owing to the tendency to metamerism of the mesencephalon and the rhombencephalon and their conformity with the type seen in the spin ...nct constrictions in the brain wall, subdividing it into a prosencephalon, mesencephalon, and rhombencephalon. These are best seen in Fig. 25, which is from the sam

...en the paraphysis in front and the posterior commissure of the midbrain or mesencephalon behind. These structures are seen in their simplest form in the embryos of

...ining parts of the hypothalamus and ventral thalamus. The remainder of the mesencephalon and diencephalon (including the retina) and the whole of the telencephalon

...alon|telencephalon]] - [[D#diencephalon|diencephalon]] - [[M#mesencephalon|mesencephalon]] - [[M#metencephalon|metencephalon]] - [[M#myeloncephalon|myeloncephalon]] ...xtends the entire length of the spinal cord and continues through into the mesencephalon.

...G.IX-X, ganglionic crest of the glossopharyngeal and vagus ganglia ; Xe., mesencephalon; 0t.pZ., otic placode ; ah., rhombomere ; R.n.c., rostral neural crest, 8.1 ...nterior to the level of the fourth somite, gaping most widely in region of mesencephalon and rliombomere A,. The position of the ventral lip of the neuropore is mar

...e sulcus limitans, which at this time continues into the diencephalon. The mesencephalon has grown considerably and comprises two segments (M1, M2).

...cup—shaped nucleus, there were no efferent fibres to the cortex nor to the mesencephalon; that the efferent fibres all ran to the other nuclei of the thalamus, thos

...ted as /«»<'-fcrfn'/i {Vorderhirn, prosencephalon), mid-brain {Mittelhini, mesencephalon), and hind-brain (77iM/e?7K'rH,metecephalon), respectively. The first vesic

...es:''' [[P#prosencephalon|prosencephalon]] (forebrain) - [[M#mesencephalon|mesencephalon]] (midbrain) - [[R#rhombencephalon|rhombencephalon]] (hindbrain) ...es:''' [[P#prosencephalon|prosencephalon]] (forebrain) - [[M#mesencephalon|mesencephalon]] (midbrain) - [[R#rhombencephalon|rhombencephalon]] (hindbrain)

:A narrow ventricular cavity within the mesencephalon formed from the cavity within the neural tube. ...cervical flexure|cervical flexure]])), lying between the [[M#mesencephalon|mesencephalon]] and [[P#prosencephalon|prosencephalon]], of the three [[F#flexure|flexure

.... II2, p. 183, Fig. 187.) Xca. 50. au, opiio vesicle; e, telencephalon; m, mesencephalon; z, diencephalon. ...a. 37. he, cerebral vesicle; in, infundibulum; ma, mammillary process; mi, mesencephalon; op, torus opticus; t, lamina ferminalis; zw, diencephalon.

...sions of unequal length, viz., the fore-brain (prosencephalon), mid-brain {mesencephalon), and hind-brain (rhombencephalon). The first division is characterized in

...poral pole, but by the end of the 3rd month, the expansion has reached the mesencephalon, and now there has appeared a third or occipital pole (Fig. 107, B) ; by th

...eek 5, neural tube differentiates into the prosencephalon (forebrain), the mesencephalon (midbrain) and the rhombencephalon (hindbrain). By week 7, the prosencephal

M., mesencephalon

...ansverse bridge of nerve fibres, the habenular commissure. The roof of the mesencephalon, which lies close behind the pineal organ, becomes slightly thickened on ea

...rt of the brain, the roof of which is thus marked off, is the mid-brain or mesencephalon. Its floor is the middle projecting part of the ventral cephalic fold. The ...he three primary brain expansions.''' von Kupffer. P.. prosencephalon; M., mesencephalon; R., rhombencephalon ; Ms., spinal cord; cw., chiasma eminence; J., infundi

1, Cerebral hemisphere, prosencephalon ; 2, thalamencephalon ; 3, mesencephalon, still single ; 4, cerebellum, epencephalon ; 5, mj-elencephalon, medulla o ...fundibulum at the lower part of the same ; m, the middle ^jrimary vesicle (mesencephalon) ; c, the cerebellum (epencephalou) ; m 0, the medulla oblongata. Figure 3

...phalic structure, and here none of the interpeduncular nucleus lies in the mesencephalon. Since this nucleus, however, is so obviously homologous with the structure

the neural folds first meet in the region of the future mesencephalon but the closure is not simply progressive from this point in both direction ...rograde. It is impossible to regard a point located at the junction of the mesencephalon with the metencephalon as the anterior end of the neural tube.

...e 33-hour chick as having a prosencephalon (probably Baer's forebrain) , a mesencephalon, rhombencephalon (perhaps together forming the "Vierhugel"?) , and no medul

M., mesencephalon M.B., midbrain 0.0., optic commissure P., pamphysis P.I., pars intercalaris

** The Mesencephalon

...hree groups; (1) an anterior group from the region of the diencephalon and mesencephalon; (2) a middle or cerebellar group in the region between the trigeminal nerv

mesencephalon.

...lying between the anterodorsal angle of the fore-gut and the floor of the mesencephalon at the point of flexure. This structure, the reduced remnant of a prechorda ...aryngeal roof; cranial, towards the telencephalon; and caudal, towards the mesencephalon.

and mesencephalon and in some other regions. (2) A progressively

...ent blue coloration in the mesenchymal tissue over the rhombencephalon and mesencephalon... .In the eight and nine day chick the escape of the citrate solution was

...ulare hem., hemisphere wall hy., hypothalamus Li., lamina terminalis mes., mesencephalon n.a.L, nucleus anterior thalami n.o., nervus opticus p.a.c.t.l., posterior

...flexure''' - (= midbrain flexure) The most cranial brain flexure, between mesencephalon and prosencephalon, of the three flexures (bends) that develop as the nuera

The posterior commissure belongs to the mesencephalon. The neuropore itself has never been followed through the successive stages

...tly confluent areas along the brain stem from the medulla oblongata to the mesencephalon. (Approx, x 2.5 mag. CA nerve cell groups, □. 5-HT nerve cell groups, 0.

M ed.f.b., medial forebralin bundle Mesen., mesencephalon

Mesencephalon, the mid-brain.

...lhmeters larger this periaxial exten.sion of the solution is complete. The mesencephalon first becomes entireW covered by the jjrussian-blue precipitate, with later ...lon) are surrounded by a much less dense mesenchyme than are the anterior (mesencephalon). This relative differentiation between the bulbar tissue and that around t

mesencephalon, and llie hind-brain or rhombencephalon, by constrictions in the lateral wa The third brain-vesicle or the vesicle of the midbrrain or mesencephalon gives rise to

...y brain vesicles:''' {{forebrain}} ( {{prosencephalon}}) - {{midbrain}} ({{mesencephalon}}) - {{hindbrain}} ({{rhombencephalon}})

...Cr.Fl. Cranial flexure. D.C. Ductus Cuvieri. Dienc. Diencephalon. M esenc. Mesencephalon. M etenc. Metencephalon. Myelenc. I and 2. Anterior and posterior divisions ...g1, g2, g3. Visceral clefts. i. Isthmus. 1. Lens. ma. Mandibular arch. ms. Mesencephalon. mt. Metencephalon. a. Otocyst; to right of otocyst is ganglion of VII and

...cephalon and myelencephalon, but not noticeably so in the diencephalon and mesencephalon. The floor plate is beginning to show its characteristic thickenings. The f ...cephalon. This is the sulcus limitans fig. 8, {Sid. Urn.). The part of the mesencephalon which

...alon, while the faint constricted portion in front of it we take to be the mesencephalon, although a part of what we have called forebrain, just at the angle, may l