551-


 * 1) Sentence ID: 551

the cells of Martinotti are chiefly found in the polymorphous layer ;


 * 1) Sentence ID: 551

the cells of Martinotti 's dendrites are short, while their axons pass out into the molecular layer. the cells of Martinotti 's dendrites may have an ascending or descending course, while their axons pass out into the molecular layer. the cells of Martinotti 's dendrites are short, while their axons form an extensive horizontal arborization. the cells of Martinotti 's dendrites may have an ascending or descending course, while their axons form an extensive horizontal arborization.


 * 1) Sentence ID: 552

Nerve Fibers.


 * 1) Sentence ID: 553

- Nerve Fibers fill up a large part of the intervals between the cells. - Nerve Fibers may be medullated or non-medullated - the latter comprising the axons of the smallest pyramidal cells. - Nerve Fibers may be medullated or non-medullated - the latter comprising the axons of the cells of Golgi.


 * 1) Sentence ID: 554

In their direction the fibers may be either tangential or radial.


 * 1) Sentence ID: 555

The tangential fibers run parallel to the surface of the hemisphere, intersecting the radial fibers at a right angle.


 * 1) Sentence ID: 556

The tangential fibers constitute several strata, of which the following are the more important :


 * 1) Sentence ID: 557

( 1 ) a stratum of white fibers covering the superficial aspect of the molecular layer ( plexus of Exner ) ; ( 2 ) the band of Bechterew, in the outer part of the layer of small pyramidal cells ; ( 3 ) the band of Gennari or external band of Baillarger , running through the layer of large pyramidal cells ; ( 4 ) the internal band of Baillarger , between the layer of large pyramidal cells and the polymorphous layer ; ( 5 ) the deep tangential fibers , in the lower part of the polymorphous layer.


 * 1) Sentence ID: 558

The tangential fibers consist of ( a ) the collaterals of the pyramidal and polymorphous cells ; ( b ) the branching axons of Golgi’s cells ; ( c ) the collaterals of the projection, commissural , or association fibers. The tangential fibers consist of ( a ) the collaterals of the cells of Martinotti ; ( b ) the branching axons of Golgi’s cells ; ( c ) the collaterals of the projection, commissural , or association fibers. The tangential fibers consist of ( a ) the collaterals of the pyramidal and polymorphous cells ; ( b ) the branching axons of Golgi’s cells ; ( c ) the terminal arborizations of the projection, commissural , or association fibers. The tangential fibers consist of ( a ) the collaterals of the cells of Martinotti ; ( b ) the branching axons of Golgi’s cells ; ( c ) the terminal arborizations of the projection, commissural , or association fibers.


 * 1) Sentence ID: 559

The radial fibers.


 * 1) Sentence ID: 560

- Some of these, viz. , the axons of the pyramidal and polymorphous cells, descend into the central white matter , while others , the terminations of the projection , commissural , or association fibers , ascend to end in the cortex.


 * 1) Sentence ID: 561

The axons of the cells of Martinotti are also ascending fibers.


 * 1) Sentence ID: 562

Special Types of Cerebral Cortex.


 * 1) Sentence ID: 563

- It has been already pointed out that the minute structure of the cortex differs in different regions of the hemisphere ; and A. W. Campbell has endeavored to prove, as the result of an exhaustive examination of a series of human and anthropoid brains , `` that there exists a direct correlation between physiological function and histological structure ''.


 * 1) Sentence ID: 566

The principal regions where the `` typical '' structure is departed from will now be referred to.


 * 1) Sentence ID: 567

1.


 * 1) Sentence ID: 568

In the calcarine fissure and the gyri bounding it, the internal band of Baillarger is absent , while the band of Gennari is of considerable thickness , and forms a characteristic feature of this region of the cortex.


 * 1) Sentence ID: 569

If a section be examined microscopically, an additional layer of cells is seen to be interpolated between the molecular layer and the layer of small pyramidal cells.


 * 1) Sentence ID: 570

This extra layer consists of two or three strata of fusiform cells, the long axes of which are at right angles to the surface ; each cell gives off two dendrites , external and internal , from the latter of which the axon arises and passes into the white central substance.


 * 1) Sentence ID: 571

In the layer of small pyramidal cells, fusiform cells , identical with the above , are seen , as well as ovoid or star-like cells with ascending axons ( cells of Martinotti ).


 * 1) Sentence ID: 572

This is the visual area of the cortex, and it has been shown by J.


 * 1) Sentence ID: 573

S.


 * 1) Sentence ID: 574

Bolton that in old-standing cases of optic atrophy the thickness of Gennari’s band is reduced by nearly 50 per cent.


 * 1) Sentence ID: 575

A.


 * 1) Sentence ID: 576

W.


 * 1) Sentence ID: 577

Campbell says :


 * 1) Sentence ID: 578

`` Histologically, two distinct types of cortex can be made out in the occipital lobe.


 * 1) Sentence ID: 579

The first of two distinct types of cortex coats the walls of the calcarine fissure ; The first of two distinct types of cortex coats the bounding convolutions of the calcarine fissure ; The first of two distinct types of cortex is distinguished by the well-known line of Gennari or Vicq d’Azyr ;


 * 1) Sentence ID: 579

the second area forms an investing zone a centimetre or more broad around the first, and is characterized by a remarkable wealth of fibers , as well as by curious pyriform cells of large size richly stocked with chromophilic elements - cells which seem to have escaped the observation of Ramón y Cajal. the second area forms an investing zone a centimetre or more broad around the first, and is characterized by a remarkable wealth of fibers , as well as by curious pyriform cells of large size richly stocked with chromophilic elements - cells which seem to have escaped the observation of Bolton. the second area forms an investing zone a centimetre or more broad around the first, and is characterized by a remarkable wealth of fibers , as well as by curious pyriform cells of large size richly stocked with chromophilic elements - cells which seem to have escaped the observation of others who have worked at this region.


 * 1) Sentence ID: 580

As to the functions of these two regions there is abundant evidence, anatomical , embryological , and pathological , to show that the first or calcarine area is that to which visual sensations primarily pass. we are gradually obtaining proof to the effect that the second investing area is constituted for the interpretation and further elaboration of these sensations.


 * 1) Sentence ID: 581

These areas therefore deserve the names visuo-sensory and visuo-psychic.


 * 1) Sentence ID: 582

``


 * 1) Sentence ID: 583

2.


 * 1) Sentence ID: 584

The anterior central gyrus is characterized by the presence of the giant cells of Betz. The anterior central gyrus is characterized by `` a wealth of nerve fibers immeasurably superior to that of any other part '' ( Campbell ). The anterior central gyrus in these respects differs from the posterior central gyrus.


 * 1) Sentence ID: 585

anterior central gyrus, together with the paracentral lobule , were long regarded as constituting the `` motor areas '' of the hemisphere ;


 * 1) Sentence ID: 585

but Sherrington and Grunbaum have shown that in the chimpanzee the motor area never extends on to the free face of the posterior central gyrus. but Sherrington and Grunbaum have shown that in the chimpanzee the motor area occupies the entire length of the anterior central gyrus, and in most cases the greater part or the whole of its width.


 * 1) Sentence ID: 586

motor area extends into the depth of the central sulcus, occupying the anterior wall. motor area extends into the depth of the central sulcus, in some places the floor ,. motor area extends into the depth of the central sulcus, in some extending even into the deeper part of the posterior wall of the sulcus.


 * 1) Sentence ID: 587

3.


 * 1) Sentence ID: 588

In the hippocampus the molecular layer is very thick. In the hippocampus the molecular layer contains a large number of Golgi cells.


 * 1) Sentence ID: 589

molecular layer has been divided into three strata : ( a ) s. convolutum or s. granulosum, containing many tangential fibers ; ( b ) s. lacunosum, presenting numerous vascular spaces ; ( c ) s. radiatum, exhibiting a rich plexus of fibrils.


 * 1) Sentence ID: 595

The two layers of pyramidal cells are condensed into one. the cells are mostly of large size.


 * 1) Sentence ID: 596

The axons of the cells in the polymorphous layer may run in an ascending, a descending , or a horizontal direction.


 * 1) Sentence ID: 597

Between the polymorphous layer is the white substance of the alveus. Between the ventricular ependyma is the white substance of the alveus.


 * 1) Sentence ID: 598

4.


 * 1) Sentence ID: 599

In the fascia dentata hippocampi or dentate gyrus the molecular layer contains some pyramidal cells, while the layer of pyramidal cells is almost entirely represented by small ovoid cells.


 * 1) Sentence ID: 600

5.


 * 1) Sentence ID: 601

The Olfactory Bulb.


 * 1) Sentence ID: 602

- In many of the lower animals this contains a cavity which communicates through the olfactory tract with the lateral ventricle.


 * 1) Sentence ID: 603

In man Olfactory Bulb 's original cavity is filled up by neuroglia. In man its wall becomes thickened. In man much more so on its ventral than on its dorsal aspect.


 * 1) Sentence ID: 604

Olfactory Bulb 's dorsal part contains a small amount of gray and white substance, but it is scanty and ill-defined.


 * 1) Sentence ID: 605

A section through the ventral part shows it to consist of the following layers from without inward :


 * 1) Sentence ID: 606

1.


 * 1) Sentence ID: 607

A layer of olfactory nerve fibers, which are the non-medullated axons prolonged from the olfactory cells of the nasal cavity. A layer of olfactory nerve fibers, which reach the bulb by passing through the cribriform plate of the ethmoid bone.


 * 1) Sentence ID: 608

At first olfactory nerve fibers cover Olfactory Bulb. At first olfactory nerve fibers then penetrate Olfactory Bulb to end by forming synapses with the dendrites of the mitral cells, presently to be described.


 * 1) Sentence ID: 609

2.


 * 1) Sentence ID: 610

Glomerular Layer.


 * 1) Sentence ID: 611

- Glomerular Layer contains numerous spheroidal reticulated enlargements, termed glomeruli , produced by the branching and arborization of the processes of the olfactory nerve fibres with the descending dendrites of the mitral cells.


 * 1) Sentence ID: 612

3 . Molecular Layer.


 * 1) Sentence ID: 614

- Molecular Layer is formed of a matrix of neuroglia, imbedded in which are the mitral cells.


 * 1) Sentence ID: 615

mitral cells are pyramidal in shape, and the basal part of each gives off a thick dendrite which descends into the glomerular layer , where a thick dendrite arborizes as indicated above. mitral cells are pyramidal in shape, and the basal part of each gives off a thick dendrite which descends into the glomerular layer , where others which interlace with similar dendrites of neighboring mitral cells.


 * 1) Sentence ID: 616

The axons pass through the next layer into the white matter of Olfactory Bulb. The axons after becoming bent on themselves at a right angle, are continued into the olfactory tract.


 * 1) Sentence ID: 617

4 . Nerve Fiber Layer.


 * 1) Sentence ID: 619

- Nerve Fiber Layer lies next the central core of neuroglia, and its fibers consist of the axons or afferent processes of the mitral cells passing to the brain ; some efferent fibers are , however , also present , and end in the molecular layer , but nothing is known as to their exact origin.


 * 1) Sentence ID: 620

Weight of the Encephalon.


 * 1) Sentence ID: 621

- The average weight of the brain, in the adult male , is about 1380 gms. ;


 * 1) Sentence ID: 621

The average weight of the brain of the female, about 1250 gms.


 * 1) Sentence ID: 622

In the male, the maximum weight of the brain out of 278 cases was 1840 gms.


 * 1) Sentence ID: 623

and In the male minimum weight of the brain out of 278 cases was 964 gms.


 * 1) Sentence ID: 624

The maximum weight of the adult female brain, out of 191 cases , was 1585 gms.


 * 1) Sentence ID: 625

and the minimum weight of the adult female brain, out of 191 cases , was 879 gms.


 * 1) Sentence ID: 626

The brain increases rapidly during the first four years of life. The brain reaches its maximum weight by about the twentieth year.


 * 1) Sentence ID: 627

As age advances, the brain decreases slowly in weight ;


 * 1) Sentence ID: 627

in old age the brain decreases takes place more rapidly, to the extent of about 28 gms.


 * 1) Sentence ID: 628

The human brain is heavier than brain of any of the lower animals, except the elephant and whale.


 * 1) Sentence ID: 629

The brain of the elephant weighs from 3.5 to 5.4 kilogm. .   brain of a whale, in a specimen 19 metres long , weighed rather more than 6.7 kilogm.


 * 1) Sentence ID: 630

Cerebral Localization.


 * 1) Sentence ID: 631

- Physiological and pathological research have now gone far to prove that a considerable part of the surface of the brain may be mapped out into a series of more or less definite areas, each of which is intimately connected with some well-defined function.


 * 1) Sentence ID: 632

The chief areas are indicated in and


 * 1) Sentence ID: 633

Motor Areas.


 * 1) Sentence ID: 634

- The motor area occupies the anterior central gyri. - The motor area occupies the frontal gyri. - The motor area occupies the paracentral lobule.


 * 1) Sentence ID: 635

The centers for the lower limb are located on the uppermost part of the anterior central gyrus ; The centers for the lower limb are located on its continuation on to the paracentral lobule ;


 * 1) Sentence ID: 635

The centers for the trunk are on the upper portion. The centers for the upper limb on the middle portion of the anterior central gyrus.


 * 1) Sentence ID: 636

The facial centers are situated on the lower part of the anterior central gyrus, centers for the tongue on the frontal operculum , while centers for the head and neck occupy the posterior end of the middle frontal gyrus. The facial centers are situated on the lower part of the anterior central gyrus, centers for the larynx on the frontal operculum , while centers for the head and neck occupy the posterior end of the middle frontal gyrus. The facial centers are situated on the lower part of the anterior central gyrus, centers for the muscles of mastication on the frontal operculum , while centers for the head and neck occupy the posterior end of the middle frontal gyrus. The facial centers are situated on the lower part of the anterior central gyrus, centers for the pharynx on the frontal operculum , while centers for the head and neck occupy the posterior end of the middle frontal gyrus.


 * 1) Sentence ID: 637

Sensory Areas.


 * 1) Sentence ID: 638

- Tactile and temperature senses are located on the posterior central gyrus. - the sense of form and solidity is on the superior parietal lobule. - the sense of form and solidity is on the precuneus.


 * 1) Sentence ID: 639

With regard to the special senses, the area for the sense of taste is probably related to the uncus. With regard to the special senses, the area for the sense of taste is probably related to the hippocampal gyrus.


 * 1) Sentence ID: 640

The auditory area occupies the middle third of the superior temporal gyrus ; The auditory area occupies the adjacent gyri in the lateral fissure ;


 * 1) Sentence ID: 640

the visual area occupies the calcarine fissure ; the visual area occupies cuneus ;


 * 1) Sentence ID: 640

the olfactory area occupies the rhinencephalon.


 * 1) Sentence ID: 641

As special centers of much importance may be noted :


 * 1) Sentence ID: 642

the emissive center for speech on the left inferior frontal gyri ( Broca ) ; the emissive center for speech on the left anterior central gyri ( Broca ) ;


 * 1) Sentence ID: 642

the auditory receptive center on the transverse and superior temporal gyri. the visual receptive center on the lingual gyrus. the visual receptive center on the cuneus.