Nerve-cells Sentence Examples
A further stage in evolution is that the muscle-cells lose their connexion with the epithelium and come to lie entirely beneath it, forming a sub-epithelial contractile layer, developed chiefly in the tentacles of the polyp. The of the evolution of the ganglioncells is probably similar; an epithelial cell develops processes of nervous nature from the base, which come into connexion with the bases of the sensory cells, with the muscular cells, and with the similar processes of other nerve-cells; next the nerve-cell loses its connexion with the outer epithelium and becomes a sub-epithelial ganglion-cell which is closely connected with the muscular layer, conveying stimuli from the sensory cells to the contractile elements.
In the latter, the segmentally arranged ganglia are more sharply marked off from the connectives than in other Chaetopods, where nerve cells exist along the whole ventral chain, though more numerous in segmentally disposed swellings.
In both cases it can be shown to be in immediate continuity with the coating of nerve-cells forming part of the longitudinal cords.
The nervous system is thus essentially epidermal in position and diffuse in distribution; but an interesting concentration of nerve-cells and fibres has taken place in the collar-region, where a medullary tube, closed in from the outside, opens in front and behind by anterior and posterior neuropores.
The nervous system, though centralized at one end of the body, contains diffused nerve-cells in the course of its tracts, which are disposed in two or more longitudinal bundles interconnected by transverse bands.
There are no well-marked specialized ganglia in the central nervous system, nerve-cells being distributed uniformly along the cords.
In these the rhythmic activity is, however, clearly secondary to rhythmic discharges of the nerve cells constituting the respiratory centre in the bulb.
Such discharges descend the nerve fibres of the spinal cord, and through the intermediation of various spinal nerve cells excite the respiratory muscles through their motor nerves.
They are, however, less excitable than are the nerve cells which innervate them.
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).
AdvertisementStretching of the muscles antagonistic to the extensors - namely, of the flexor muscles - reduces the jerk by inhibiting the extensor spinal nerve cells through the nervous impulses generated by the tense flexor muscles.
Examination of the cerebellum by the method of Wallerian degeneration has shown that a large number of spinal and bulbar nerve cells send branches up into it.
It has been suggested that the gradual cumulative result of the activity of the nerve cells during the waking day is to load the brain tissue with "fatigue-substances" Theories of which clog the action of the cells, and thus periodi cally produce that loss of consciousness, &c., which is sleep. Such a drugging of tissue by its own excreta is known in muscular fatigue, but the fact that the depth of sleep progressively increases for an hour and more after its onset prevents complete explanation of sleep on similar lines.
The long-continued incitement to catabolism of the waking day thus of itself predisposes the nerve cells towards rebound into the opposite phase; the increased catabolism due to the day's stimuli induces increase of anabolism, and though recuperation goes on to a large extent during the day itself, the recuperative process is slower than, and lags behind, the disintegrative.
In 1842 he wrote a thesis in which he announced the discovery of nerve-cells in ganglia.
AdvertisementThus in diphtheria changes in both nerve cells and nerve fibres have been found, and in tetanus minute alterations in the nucleus and protoplasm of nerve cells.
There is therefore strong evidence that antitoxin molecules do exist as part of the living substance of nerve cells.
They both stimulate the grey nerve-cells in the brain and cord, this being the foundation of their dietetic value and their use as nervine stimulants.
The problem is that only 0.2% of the damaged nerve cells are replaced.
Numerous chemical and biological phenomena are modeled by non-linear ODE's, for example chemical reactions and voltage clamped nerve cells.
AdvertisementThis is normally prevented by a tiny messenger substance known as " GABA " which makes the nerve cells less excitable.
This causes the membrane potential to become more negative and results in muscle and nerve cells becoming less excitable.
New branches of the remaining nerve cells were sent out to adopt the orphaned muscle fibers.
In other words, the high- intensity training allowed nerve cells to ' reach out and touch ' an increased number of muscle fibers.
The protein that is produced protects these mature nerve cells from death following an injury.
AdvertisementThe precise function of the gene is unknown, although it is thought to help nerve cells communicate with each other.
Sensory nerve cells carry information about muscle tension and body position to motor nerve cells in the spinal cord to control muscle contraction.
Using rats, scientists showed that a damaged area in the brain - akin to human stroke - is infiltrated by new nerve cells.
All these diseases resulted in parts of the brain becoming spongy the nerve cells replaced by holes.
It has been urged that the neurons retract during sleep, and that thus at the synapses the gap between nerve cell and nerve cell becomes wider, or that the supporting cells expand between the nerve cells and tend to isolate the latter one from the other.
As a result muscles which are commanded by the nerve cells in these areas of the spinal cord become affected.
One of the eight B vitamins, vitamin B12 is a water-soluble vitamin that aids in the healthy maintenance of nerve cells and red blood cells.
Serotonin is a chemical in the brain that sends electrical signals to and from nerve cells.
This is a rare medical condition where the affected individual's own nervous system goes into overdrive and starts attacking the nerve cells.
Treatments may help either cognitive or behavioral symptoms by working on emotional centers in the brain or improving the activity of nerve cells to help inhibit cognitive decline.
As scientists have since learned, motor and cognitive skills deteriorate as brain cells and connections between nerve cells die.
Narcolepsy is thought to be caused by abnormalities in the structure and the function of nerve cells in the brain.
A disruption in the blood supply to the brain starves the brain of oxygen-rich blood and causes the nerve cells in that area to become damaged and die within minutes.
Fortunately, the nerve cells are not always completely destroyed.
If the nerve cells are completely destroyed; however, paralysis is permanent.
Once a child gets the virus, it stays in his body permanently, hiding in nerve cells near the ear.
It lives in nerve cells where the immune system cannot find it.
The nerve cells most affected by FA are those in the spinal cord involved in relaying information between muscles and the brain.
Motor nerve-Motor or efferent nerve cells carry impulses from the brain to muscle or organ tissue.
One part of the brain that was as of 2004 being studied is the amygdala, an almond-shaped body of nerve cells involved in normal fear conditioning.
Gangliosides are fatty substances necessary for the proper development of the brain and nerve cells (nervous system).
Ganglioside-A fatty (lipid) substance found within the brain and nerve cells.
Herpes zoster virus-Acute inflammatory virus that attacks the nerve cells on the root of each spinal nerve with skin eruptions along a sensory nerve ending.
Symptoms that have a waning course with recurrences and worsen over time suggest a disease that destroys nerve cells.
Corticospinal tract-A tract of nerve cells that carries motor commands from the brain to the spinal cord.
Normal voluntary muscle contraction begins when electrical signals are sent from the brain through the spinal cord along nerve cells called motor neurons.
A neurotransmitter is a chemical produced by the body that conveys nerve impulses across the gaps (synapses) between nerve cells.
The basal ganglia are groups of nerve cells deep in the brain that control movement as well as emotion and certain aspects of thinking.
Children diagnosed with Hirschsprung's disease lack nerve cells (ganglia) in the large intestine, severely affecting the wavelike movements that propel material through the colon.
Hydantoins, the class that includes phenytoin, mephenytoin, and ethotoin, seem to work by reducing the flow of sodium into and out of nerve cells.
The extensive network of nerves in the brain and the rest of the nervous system are made up of nerve cells.
These nerve impulses then stimulate the end of an axon to release chemicals called neurotransmitters that spread out and communicate with the dendrites of neighboring nerve cells.
Many nerve cells have long, wire-like axons that are covered by an insulating layer called the myelin sheath.
In untreated PKU patients, abnormally high phenylalanine levels in the blood and brain can produce nerve cells with deformed axons and dendrites and cause imperfections in the myelin sheath referred to as hypomyelination and demylenation.
Some research suggests that nerve cells of PKU patients also have difficulty absorbing tyrosine.
These dormant viruses are concentrated in nerve cells near the spinal cord and may reactivate in adults, causing the disease herpes zoster or shingles.
Polio-Poliomyelitis, an acute viral disease marked by inflammation of nerve cells of the brain stem and spinal cord and can cause paralysis.
More often than not the blisters disappear without treatment in two to 10 days, but the virus remains in the body, lying dormant among clusters of nerve cells until another outbreak is triggered.
When the antibodies encounter allergens, they trigger release of the granules, which spill out their chemicals onto neighboring cells, including blood vessels and nerve cells.
The nerve cells themselves, with long branches (dendrites) that receive signals from other nerve cells, make up the gray matter that lies in a butterfly-shaped region in the center of the spinal cord.
Hirschsprung's disease is caused when certain nerve cells (called parasympathetic ganglion cells) in the wall of the large intestine (colon) do not develop before birth.
Sensory information provides critical input on the current position and velocity of body parts, and spinal nerve cells (neurons) help prevent opposing muscle groups from contracting at the same time.
Parkinson's disease-A slowly progressive disease that destroys nerve cells in the basal ganglia and thus causes loss of dopamine, a chemical that aids in transmission of nerve signals (neurotransmitter).
Progressive supranuclear palsy-A rare disease that gradually destroys nerve cells in the parts of the brain that control eye movements, breathing, and muscle coordination.
The loss of nerve cells causes palsy, or paralysis, that slowly gets worse as the disease progresses.
This is a naturally occurring vitamin essential for developing red blood cells and nerve cells.