Word Finder - ganglion

definition

An encapsulated collection of nerve-cell bodies, located outside the brain and spinal cord.

definition

Any of certain masses of gray matter in the brain, as the basal ganglia.

definition

(by extension) A centre of intellectual or industrial force, activity, etc.

definition

A cystic tumour on a tendon sheath or joint capsule; a ganglion cyst.

D, Oesophageal ganglion connected with the buccal.

Actaeon is prosobranchiate, the visceral commissure is twisted in Actaeon and Chilina, and even slightly still in Bulla and Scaphander; in Actaeon and Limacina the osphradium is to the left, innervated by the supra-intestinal ganglion.

The euthyneurous visceral loop is long, and presents only one ganglion (in Aplysia camelus, but two distinct ganglia joined to one another in Aplysia hybrida of the English coast), placed at its extreme limit, representing both the right and left visceral ganglia and the third or abdominal ganglion, which are so often separately present.

It is also seen to be connected with a more remote ganglion - the genital.

Spengel's observation of the osphradium and its nervesupply in these forms; the nerve to that organ, which is placed somewhat anteriorly - on the dorsal surface - being given off from the hinder part (visceral) of the right compound ganglion - the fellow to that marked A in fig.

On account of the shortness of the visceral loop and the proximity of the right visceral ganglion to the oesophageal nerve-ring, the nerve to the osphradium and olfactory ganglion is very long.

The continuous layer of cells from which the nervous system is developed undergoes a segmentation analogous with that we have described as occurring in the ventral plate; there is thus formed a pair of contiguous ganglia for each segment of the body, but there is no ganglion for the telson.

The nervous system of the embryonic head exhibits three ganglionic masses, anterior to the thoracic ganglionic masses; these three masses subsequently amalgamate and form the sub-oesophageal ganglion, which supplies the trophal segments.

In front of the three masses that will form the sub-oesophageal ganglion the mass of cells that is to form the nervous system is very large, and projects on each side; this anterior or " brain " mass consists of three lobes (the prot-, deut-, and tritencephalon of Viallanes and others), each of which might be thought to represent a segmental ganglion.

These three divisions subsequently form the supra-oesophageal ganglion or brain proper.

The nervous system is represented by an oesophageal collar and a suboesophageal ganglion, whence paired nerves pass outwards to innervate the anterior extremity and backwards towards its posterior end.

The central ganglion of the nervous system lies in the proboscissheath or -septum.

In the male at ea least there is also a genital ganglion.

In Discinisca and Lingula, however, the sub-oesophageal ganglion is not drawn out, but lies medianly; it gives off two posteriorly directed nerves to the stalk, which in Lingula unite and form a substantial nerve.

Blochmann, the immensely long drawn out supra-oesophageal ganglion.

Medianly, it has its origin in the sub-oesophageal ganglion, which, like the supra-oesophageal, is drawn out laterally, though not to the same extent.

In the middle line the sub-oesophageal nerve mass is small; the ganglion is in fact drawn out into two halves placed on either side of the body.

The wide divarication of the lateral cords in the prosoma and their connexion by transverse commissures, together with the " attraction " of ganglia to the prosomatic ganglion group which properly belong to hinder segments, are very nearly identical in the two animals.

The form and disposition of the ganglion cells are also peculiar and closely similar in the two.

A very remarkable feature in Limulus, first described by Owen, is the close accompaniment of the prosomatic nerve centres and nerves by arteries, so close indeed that the great ganglion mass and its out-running nerves are actually sunk in or invested by ch.

A, Fasciola hepatica, from the ventral surface (X 2); the alimentary and nervous systems only shown on the left side of the figure, the excretory only on the right; a, right main branch of the intestine; c, a diverticulum; g, lateral ganglion; n, lateral nerve; o, mouth; p, pharynx; s, ventral sucker; cs, cirrus sac; d, left anterior dorsal excretory vessel; m, main vessel; v, left anterior ventral trunk; x, excretory pore.

The nervous system consists of a ganglion or brain, which lies dorsally about the level of the junction of the pharynx and the stomach, a nerve ring and a segmented neutral cord.

Here, and in the narrow neck of land between the Appomattox and the James, was the ganglion of the Confederacy, and the struggle for its possession was perhaps the greatest of modern history.

The nerve ganglion is formed by an ingrowth of epiblast, and so are the pedal glands.

Left cerebro-pleuro-visceral ganglion.

But it has since been discovered that in the Protobranchia the cerebral ganglia and the pleural are distinct, each giving origin to its own connective which runs to the pedal ganglion.

Pedal and pleural on each side are connected by a pleuro-pedal connective Each pleural ganglion gives off a long nerve which supplies the viscera, and the two unite posteriorly below the intestine.

The nervous system consists of a cerebral ganglion in the head, a conspicuous ventral ganglion in the trunk, and of lateral cornmissures uniting these ganglia on each side.

The cerebral ganglion also gives off a nerve on each side to a pair of small ganglia, united by a median commissure, which have sunk into and control the muscles of the head.

In front of the buccal mass is a median cerebral ganglion.

From this pass off two pairs of cords, the pleural and pedal, in Proneomenia separate from their origin, in Neomenia united at first and diverging at a pleural ganglion.

The supra-rectal commissure may be present and bear an ovoid ganglion; or may be wanting.

There are no distinct ganglia, but ganglion cells are uniformly distributed along the ventral side of the cord.

When, for instance, the axons of the ganglion cells of the retina are severed by section of the optic nerve, and thus their influence upon the nerve cells of the visual cerebral centres is set aside, the nerve cells of those centres undergo secondary atrophy (Gadden's atrophy).

Exner first showed, many years ago, that the nerve impulse travels through the spinal ganglion at the same speed as along the other parts of the nerve trunk - that is, that it suffers no delay in transit through the perikarya of the afferent rootneurons.

There is a single unsegmented nerve-cord which runs along the ventral middle line and enlarges posteriorly into a caudal ganglion and anteriorly in a ganglion, the brain, which is not supra-oesophageal.

This cord is neither elastic nor solid, but consists of nerve tissue, fibres and ganglion cells, surrounding a small central canal.

Each of the visceral ganglia is connected or combined with an olfactory ganglion underlying an area of specialized epithelium, which constitutes the olfactory organ, the osphradium.

In the severest forms of tic doloureux complete relief has followed the extirpation of the Gasserian ganglion.

The brain, or supra-oesophageal ganglion, shows various degrees of complexity.

Close to each cerebral ganglion is a pleural ganglion, and each is connected by a long nerve with the pedal ganglion of the same side, the two connectives of either side being united in the distal part of their course.

Each contains a terminal ganglion connected with sensory cells in the lateral pit.

He also demonstrated that no motor nerve ever passes through a ganglion.

It gives rise to a nerve-ganglion mass, the prostomial ganglion.

Probably it is fused with the D, Deuterocerebrum, consist protocerebrum, and may also be ing of ganglion cells be concerned in the history of the very longing to the second or peculiar paired eyes of Peripatus, mandibular somite.

A ganglion cyst is a bump or mass that forms under the skin.

The cell bodies of these sensory nerves are grouped together in a small swelling called the dorsal root ganglion.

The patient is placed in the sitting position to facilitate the spread of anesthesia inferiorly to the stellate ganglion.

Other people believe that the virus only resides within the nerve ganglion, which is further away from the skin.

The overall length of the cochlea is shorter in Down's syndrome and the spiral ganglion cell population is reduced.