Section of medulla oblongata from case of gas poisoning, stained by Nissl method, showing the swollen cells of the nucleus ambiguus.
Section of medulla oblongata from case of shell-shock with burial, stained by Nissl method, showing the swollen cells of the nucleus ambiguus.
After having trepanned the skull of a chloroformed dog, a little bit of the medulla of an animal which had died of hydrophobia was deposited on the surface of the brain.
At the moment of death the medulla oblongata is always rabic.
This last would be progressively attacked throughout, if death from the medullaoblongata did not almost always supervene before the propagation of the virus can become general.
As the grey matter of the cord enters the medulla it loses its crescentic arrangement.
The inferior medullary velum, a reflection of the pia mater and epithelium from the back of the medulla to the inferior vermis, closes it in below.
The ventral part of each crus forms the crusta, which is the continuation forward of the anterior pyramidal fibres of the medulla and pons, and is the great motor path from the brain to the cord.
The longitudinal fibres ascend from the medulla oblongata and leave the pons by emerging from its upper surface as fibres of the two crura cerebri.
A constriction also occurs in the hind vesicle or rhombencephalon, dividing it into an anterior part, the metencephalon, from which the cerebellum is developed, and a posterior or myelencephalon, the primitive medulla oblongata.
The grey matter of the medulla oblongata, which contains numerous multipolar nerve cells, is in part continuous with the grey matter of the spinal cord, and in part consists of independent masses.
Transverse Section through the Human Medullain the Lower Olivary Region.
The grey matter in the interior of the medulla appears, therefore, on the floor of the ventricle and is continuous with the grey matter near the central canal of the cord.
Mesial section through the Corpus Callosum, the Mesencephalon, the Pons, Medulla and Cerebellum.
Situated on its floor are the fasciculi teretes, striae acusticae, and deposits of grey matter described in connexion with the medulla oblongata.
The Fourth Ventricle is the dilated upper end of the central canal of the medulla oblongata.
If a section is made transversely through the medulla about the apex of the fourth ventricle three important bundles of fibres are cut close to the mid line on each side (see fig.
The pons possesses a median raphe continuous with that of the medulla oblongata, and formed like it by a decussation of fibres in the mesial plane.
They say the medulla oblongata is irritated, and the patient learns that he is suffering from neurosis of the nervus vague.
Development of brain fibre laterally gives a wide head, longitudinally, from themedulla oblongata to the forehead and to the occiput, a long head.
These centres in the medulla preside over the centres in the spinal cord which are in direct relation to the inspiratory and expiratory muscles.
It is, however, probable that there is a direct relation between the brain and the spinal nerve centres which control the costal and abdominal muscles independently of the respiratory centres of the medulla oblongata (vide fig.
Arrows are represented passing from the centre of phonation to the lower centres in the medulla which preside over the muscles of the jaw, tongue, lips, and larynx.
The speech zone of the left hemisphere directly controls the centres in the medulla oblongata that preside over articulation and phonation; innervation currents are represented by the arrows coming from the higher to the lower centres.
With voluntary breathing the respiratory centre in the medulla has nothing to do.
The stem of the brain, the medulla oblongata, and the spinal cord, consists externally of white matter, the grey matter being internal.
The narrow central canal of the spinal cord continues above into the quadrangular fourth cerebral cavity of the medulla oblongata, the floor of which is the quadrangular depression.
Finally, we have the fifth and last section, the medulla oblongata (Figure 2.
The central nervous system or central marrow (medulla centralis) is the real organ of psychic action in the narrower sense.
Under the latter we can see the medulla oblongata.
To obtain attenuation of the virus it was sufficient to dry the medulla taken from an infected rabbit.
In what way can the germ-cells be affected by molecular or histological changes in the pons varolii and medulla oblongata?
If the structure of the medulla and cortex (see figure above) is examined under the compound microscope, you will find these regions to be composed of a vast number of tiny branched and twisted tubules.
The medulla is, in structure, part of the spinal cord, and is made up largely of fibers running longitudinally.
No one will deny, that the medulla of the brain and nerves has a certain figure; which, as it is diffused through nearly the whole of the body, must have nearly the figure of that body.
Hence it appears, that as the muscles consist of larger fibres intermixed with a smaller quantity of nervous medulla, the organ of vision consists of a greater quantity of nervous medulla intermixed with smaller fibres.
When the medulla of the back was completely divided, there was momentary loss of sight, loss of memory for fifteen minutes, and permanent insensibility in all the lower parts of the body.
From these appearances, we were at no loss to fix the cause of this gradual palsy in the alteration of the medulla spinalis and oblongata.
It thence appears, that none of the characteristic symptoms of this malady are produced by compression, laceration, or complete division of the medulla spinalis.
All that has been ventured to assume here, has been that the disease depends on a disordered state of that part of the medulla which is contained in the cervical vertebræ.
Whilst conjecturing as to the cause of this disease, the following collected observations on the effects of injury to the medulla spinalis, by Sir Everard Home, become particularly deserving of attention.
Cutting the medulla at its junction with the pons causes, then, an immediate and direct elevation of temperature, without disturbance of the circulation.
The vaso-motor nerves have their governing centre in that upper portion of the spinal cord which is within the skull, the so-called medulla oblongata.
If, instead of cutting the spinal cord, we separate the medullaoblongata from the pons, an immediate rise of temperature occurs, and continues until death, whether the operation be performed in a cold or heated room.
The upper end of the medulla oblongata is continuous with a nervous mass which joins the two brain hemispheres together, and hence is known as the pons or bridge.
The experiments which have been adduced prove that there are nerves whose function it is to control the general vital chemical actions, and that the governing centre of these nerves is situated above the medulla oblongata.
The decomposed blood excites the medulla oblongata, and the latter impetuously demands a movement of inspiration.
In building their nest Mr. and Mrs. Ceryle select some high embankment where they excavate a small tunnel from three to six feet long, widened at the far end into a chamber perhaps fourteen inches in diameter.
A good dog takes the stubble field with the wind in his favor.
The brain has a central organ, which is a continuation of the spinal cord, and to which anatomists have given the name of medulla oblongata.
The corpora quadrigemina are four tubercles which connect the cerebrum, cerebellum, and medulla oblongata to each other.
The most important part of the whole brain seems to be one particular part of the central organ, or medulla oblongata.
Ten of these pairs of nerves originate in themedulla oblongata.
It is divided into three parts: the cerebrum, the cerebellum, and the medulla oblongata.
The medulla oblongata, with the crossing of some of its fibres exhibited.
What do some physiologists assert of the medulla oblongata?
Some physiologists assert, that the medullaoblongata is the point at which excitement to motion commences, and sensation terminates; and also, that it possesses the power of originating motion in itself.
It is remarkable that the nerves which arise from the right side of the spinal cord communicate with the left hemisphere of the cerebrum, and vice versa; this results from the crossing of the fibres in the medulla oblongata.
Defn: Furnished with a medulla or marrow, or with a medullary sheath; as, a medullated nerve fiber.
Defn: The posterior part of the medulla oblongata.
Defn: Of or pertaining to themedulla oblongata; medullar.
Defn: Formed like a rope; -- applied especially to several ropelike bundles or masses of fibers on the dorsal side of the medulla oblongata.
As the vaso-motor centre in the medulla oblongata is also stimulated, as well as the contractions of the heart, there is thus trebly caused a very great rise in the blood-pressure.
It has a root of characteristic appearance, and shows a well-marked medulla containing a structure of narrow cells.
In rabbit's hair the medulla is also very pronounced and is characterised by its structure of curious quadrilateral cells, which may either form a single row or increase to four or eight rows as the hair becomes wider.
In those fibres in which it is present the medulla is very pronounced and tapers towards the apex.
The medulla is well marked, but lacks the cellular structure to be seen in the hair of the cat and rabbit.
Straight, lank, long and coarse, round or nearly so in section, with the medulla or pith easily distinguishable, and almost without exception black.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "medulla" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: axis; center; core; heart; hub; kernel; marrow; middle; nave; navel; nucleus; pith; pivot; umbilicus
