Ipecacuanha owes its properties to the presence of rather more than 1% of the alkaloid emetine, which, with the exception of traces, occurs only in the cortical portion of the root.
The activity of the drug resides chiefly in the cortical portion, and hence the presence of the stem diminishes its value.
Except in the presence of infection, separated fragments live and become reunited, but they may unite in such a manner as to project towards the brain and, by irritating the cortical centres, cause traumatic epilepsy.
Effusions into the corticalmotor areas give rise to irritation or paralysis of the muscles governed by the affected centres.
When the fibres of the nerve are implicated in any part of their course between the cortical centre and the nucleus in the lower part of the pons, the paralysis is of the upper neurone (cerebral) type.
No irritative phenomena are associated with such a sub-cortical lesion.
During the progress of the symptoms there is frequently evidence of direct pressure upon definite cortical centres or cranial nerves, giving rise to focal symptoms.
The membranes are congested and thickened, the veins of the arachno-pia engorged, and the superficial layers of the cortical grey matter may share in the process (encephalitis).
The cortical centres for vision lie on the median surfaces of the occipital lobes in the neighbourhood of the calcarine fissure.
Thus the treatment of an unfertilized egg without membrane with a hypertonic solution combines two effects, first the general cytolytic alteration of the cortical layer of the membrane and the corrective effect of the hypertonic solution.
Lillie thinks that the KCN in this experiment merely inhibits the change of the cortical layer necessary for development.
It seems to me that this can be understood if we suppose that it depends upon the destruction of an emulsion in the cortical layer of the egg.
It appears from this as though the change in the cortical layer which leads to the development of the egg and the increase in the rate of oxidations were reversible in the egg of Arbacia.
Thus the writer has shown that in the egg of Arbacia the effect of the cortical alteration of the egg induced by the butyric acid treatment or by the treatment with bases can be reversed.
It is quite possible that in these phenomena of reversal not the whole of the cortical layer has undergone alteration.
The writer suggested that the destruction of an emulsion in the cortical layer might possibly be the essential feature of the alteration leading to membrane formation and development.
The general appearance and arrangement of the neurones in a particle of cortical grey matter are shown in fig.
The cortical neurone therefore collects impulses in the region of cortex just about its perikaryon and discharges them to other regions, some not cortical or even cerebral, but spinal, &c.
The tendency of physiology is to regard the actions of the cortex as reactions to impulses communicated to the cortical cells by nerve-channels reaching them from the sense organs.
The part of the cortex immediately behind the central fissure seems to be the main cortical goal for these upward-conducting paths.
Still less is there satisfactory knowledge regarding the existence ofcortical areas concerned with sensations originated in the alimentary canal.
The pallium is reptilian in character, though its cortical area is more extensive.
It is surrounded by a cortical field which, though intimately connected with it by manifold conducting fibres, &c.
The roof of the telencephalon is mainly epithelial, and contains no traces of cortical structure.
The corticalarea for the thumb is larger than those for the whole abdomen and chest combined.
As far as the present writer can find from reference to books and from the clinical experience of others, "pain" is unknown as an aura in cortical epilepsy, or at most is of equivocal occurrence.
In the latter animal the cortical area is so extensive as to be thrown into many and deep sulci, and yet the Echidna is one of the lowliest of mammals in other respects.
In these, a rough glassy enamel covers the cortical part, of such hardness, as to strike sparks with steel.
Nine ounces of the cortical portion of the bran were obtained.
Young trees abound most in the white cortical layers, and are hence more productive of tannin under equal weights, than the barks of old trees.
The outside of the tusk is covered by the cortical part, which is softer and less compact than the interior substance, with the exception of the brown plate that sometimes lines the interior cavity.
Cortical Projection of Vestibular and Facial Nerves in the Cat.
Brief electrical stimulation of cat corticaltissue causes an increase in nucleic acid cytidine and adenine, thus indicating a synthesis of altered polynucleotides.
The use of brief electrical stimulation of the vestibular nerve in order to elicit a cortical response has been of great value for the mapping of these areas.
A significant increase in RNA of nerve cells of the fifth to sixth cortical layers on the right side of the brain was observed.
The gain in weight of corticaltissue is relatively larger than the increase in enzymatic activity.
Rats given enriched experience develop, in comparison with their restricted littermates, greater weight and thickness of cortical tissue and an associated proportional increase in total acetylcholinesterase activity of the cortex.
The cortical centers for the voluntary muscles extend over most of the lateral psychic zones of the brain, so that their culture is brain building.
The second level regroups these simple movements by combinations and associations of corticalstructure in wider, more complex mechanisms, producing a higher class of movements.
Transverse sections, showing the distinction between the cortical and medullary substances, and the central collection of pigmentary matter, sometimes found in the latter.
These ganglia form the corticalcovering of the brain, and are also found in the interior of the spinal cord.
It is not difficult to perceive the relation existing between a defective brain weight, paucity of the gyri, deficiency of properly developed cortical cells and such an elementary form of mental aberration as simple imbecility.
Where, for example, the cortical area for vision overlaps that of the centre for forearm and hand, the associating fasciculus underlying the debatable land is subservient to the co-ordinations employed in writing and drawing.
That an irritative lesion in the line of the centripetal tracts can influence cortical life is shown by thalamus lesions in which hallucinations are sometimes present.
This explains the manifold epileptic aura, which is simply an isolated, exaggerated, and limited cortical function.
The kidneys present no marked changes when death has taken place early in the attack, or at most only exhibit a lighter color than usual of the cortical substance and a darker one of the pyramids.
As a rule, the epithelium becomes granular earlier and to a marked degree in the cortical than in the tubular portion.
The podetia of some species of Cladonia possess no cortical layer at all.
The cortical layer is usually more developed on the side towards the light, while in many lichens this is the only side provided with a cortical layer.
The medullary layer, which usually forms the main part of the thallus, is distinguished from the cortical layer by its looser consistence and the presence in it of numerous, large, air-containing spaces.
By the fusion of the hyphae in the middle of the mycelium a pseudo-parenchymatous cortical layer has begun to form.
The "recurrent sensations" experienced after prolonged occupation with some one kind of sensory object may be regarded as due to an abnormal excitability of the cortical system concerned, resulting from its unduly prolonged exercise.
Another sign of age is the tendency to degeneration found in the pineal gland, the cortical substance, the optic and striate thalami, and in the brain capillaries.
The subcutaneous cellular tissue of the thorax is reddish and the upper part of the cortical substance of the brain of a greenish tint.
Weldon showed that the cortical part of the suprarenals in the lizard was derived from the wall of the glomerulus of a number of mesonephric tubules.
Elasmobranchs, or the corticalpart of the adrenals of the higher vertebrates, there has been no invasion of sympathetic ganglion-cells.
Ammocoetes brain, or in the cortical layers of the optic ganglia of all arthropods.
There are at present two camps--those who maintain the older views of precise cortical centres, and those who follow Marie and insist upon a revision.
These several cortical regions are connected by systems of subcortical fibres to two regions in front of the ascending frontal convolution (vide fig.
The cortical centres or structures with specialised functions localised in particular regions of one hemisphere are associated by fibres passing to the same region in the opposite hemisphere by this bridge.
These, therefore, spread into the leaves, and there communicate with the extremities of the vessels of the cortical layers, into which they pour their contents.
If incisions are made into the alburnum and cortical layers, may not the ascending and descending sap be procured in the same manner as the peculiar juice is from the vessels of the parenchyma?
Of the Bark, consisting of Epidermis, Parenchyma, and Cortical Layers.
The bark is composed of the epidermis, the parenchyma, and the cortical layers.
The cortical layers are annually renewed, the old bark being converted into wood.
The cortical layers are immediately in contact with the wood; they abound with tannin and gallic acid, and consist of small vessels through which the sap descends after being elaborated in the leaves.
That function is performed by the tubes of the alburnum, or wood, which is immediately beneath the cortical layers.
The cortical substance is composed of bundles of cells, separated by a stroma, which have a different appearance in different parts.
Each lobe is divided into a large number of lobules divided by areolar tissue, and each of these, under the microscope, is seen to consist of a cortical and medullary part.
To the naked eye the cortical part is yellow while the medullary is red.
In a vertical transverse section each gland is seen to consist of two parts, cortical and medullary.
The whole of the kidney may be affected with anæmia or defect of blood, or this may be confined to the cortical substance, or even to the tubular.
When the brain is cut, it is found to be composed of two substances, essentially different in construction and function--the cortical and the medullary.
We are bound to assume the existence of still more remotely interconnected subconsciousnesses for the infra-cortical (lower) brain-centers, and so on.
We speak of psycho-physiological identity only when we mean, on the one hand, the cortical neurocyme which directly conditions the conscious phenomena known to us, on the other hand, the corresponding phenomena of consciousness.
The corticalportion of the large worker brain is, moreover, extremely rich in cellular elements.
The corresponding cortical receptive areas are capable, in the first instance, merely of registering what is brought to them by the sense-stimuli and these are mainly associated spatial images for sight and tone or sound-sequences for hearing.
Anatomically, at least, the sensory pathways to the brain and their cortical centers are sharply separated from the centers belonging to the volitional pathways to the muscles.
But that appearance that you call a cork," says he, "is nothing but the outward spacies and external qualities of the cortical nathur.
In the cortical portion outside the sclerenchymatous band, small vascular bundles occur in the stems of Panicum colonum, Panicum Crus-galli and Panicum fluitans.
Transverse section of the corticalportion of the root of Andropogon Sorghum.
Bruce has established the fact that thyroid feeding acts as a direct cerebral stimulant, which he thinks "may prove advantageous in cases where the highercortical cells remain in an anergic condition.
Would they seem as real as the impulse to check the whatchamacallits or tighten up your cortical thingamajigs?
With dispatch I activated cortical area omicron, re-routed the blood supply, drew an emergency oxygen source from stored fats, diverting the necessary energy to break the molecular bonds.
The excitement of this organ causes dilatation of its vessels, and increased irritability of the cortical instrument of perception.
According to this view, the state of wakefulness is maintained by a certain degree of activity in the cortical substance of the brain.
In a third class of cases the agitation of the brain is produced by the direct action of certain chemical agents upon the cortical substance.
The explosive constituents of the cortical protoplasm are then inadequately renewed after mental activity, and the sensitive portions of the brain are no longer fitted to manifest the highest forms of intelligent activity.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "cortical" in a variety of sentences. We hope that you will now be able to make sentences using this word.
