How to use Nerve-cell in a sentence
On the whole the ganglia are strongly individualized in the Pectinibranchia, nerve-cell tissue being concentrated in the ganglia and absent from the cords.
Gray matter contains nerve cell bodies and unmyelinated axons.
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.
There seems to be little doubt, notwithstanding, that one of the chief functions of the nerve cell is that of the propagation of a trophicj influence along its axon.
Each neuron or nerve cell is a morphologically distinct and discrete unit connected functionally but not structurally with its neighbours, and leading its own life independently of the destiny of its neighbours.Advertisement
But when neurons are linked together it is found that nerve impulses will only pass from neuron A to neuron B, and not from neuron B to neuron A; that is, the transmission of the excited state or nervous impulse, although possible in each neuron both up and down its own cell branches, is possible from one nerve cell to another in one direction only.
The inference is that the "fatigue substances" generated in the muscle fibres in the course of their prolonged contraction injure and paralyse the motor end plates, which are places of synapsis between nerve cell and muscle cell, even earlier than they harm the contractility of the muscle fibres themselves.
On the other hand, in some neurons, after severance of the axon from the rest of the cell (spinal motor cell), the whole nerve cell as well as the severed axon degenerates, and may eventually die and be removed.
This death of the sheath as well as of the axis cylinder shows that it, like the axis cylinder, is a part of the nerve cell itself.
It seems, especially in the case of the nexus between certain neurons, that the influence, loss of which endangers nutrition, is associated with the occurrence of something more than merely the nervous impulses awakened from time to time in the leading nerve cell.Advertisement
The nerve cell just prior to sleep is still well capable of response to stimuli, although perhaps the threshold-value of the stimulus has become rather high, whereas after entrance upon sleep and continuance of sleep for several hours, and more, when all spur to the dissimilation process has been long withheld, the threshold-value of the sensory stimulus becomes enormously higher than before.
The motor nerve cell body has a long fiber called an axon, which extends from the central nervous system to the muscles.
Nerves These are made up of bundles of nerve cell axons.
The narrowing of the hole is detected by a nerve cell dendrite which projects into it, producing an electric signal.
The first nerve cell communicates with the next by releasing neurotransmitters into the synapse.Advertisement
A nerve cell contains a high concentration of potassium salt whilst the chemical composition outside the cell membrane is higher in sodium salt.
It is this wide range of dynamic peculiarities above the common range of known physical and chemical molecules which excites our wonder; and a reflection of these peculiar properties is seen in their affinities for this or that toxic or constructive agent, whereby the peculiarity, for example, of a particular kind of nerve cell may be altered, antagonized, reinforced or converted.
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.
If a threat is especially severe or recurs frequently, such as protracted combat or living with abuse, the chemicals that carry messages from one nerve cell to another become depleted, and the brain becomes sluggish and inefficient.
Most studies agree that symptoms of Tourette syndrome involve the chemicals in the brain that help transmit information from one nerve cell in the brain to another.Advertisement
Neurotransmitter-A chemical messenger that transmits an impulse from one nerve cell to the next.
Motor neuron-A nerve cell that specifically controls and stimulates voluntary muscles.
Nociceptor-A nerve cell that is capable of sensing pain and transmitting a pain signal.
Stimulating a nerve cell triggers nerve impulses (signals) that speed down the axon.
The type of child that Kagan's research group identified as inhibited, for example, appears to have the same pattern of disturbed nerve cell activity that has been identified in adults diagnosed with mood or anxiety disorders.Advertisement
Hirschsprung's disease occurs early in fetal development when, for unknown reasons, there is either failure of nerve cell development, failure of nerve cell migration, or arrest in nerve cell development in a segment of bowel.
Parasympathetic ganglion cell-Type of nerve cell normally found in the wall of the colon.
The work of Camillo Golgi (Pavia, 1885 and onwards) on the minute structure of the nervous system has led to great alteration of doctrine in neural physi nerve cells, that is to say, the fine nerve fibres - since all nerve fibres are nerve cell branches, and all nerve cell branches are nerve fibres - which form a close felt-work in the nervous centres, there combined into a network actually continuous throughout.
The alkaloid curarin causes motor paralysis by attacking in a selective way this junction of motor nerve cell and striped muscular fibre.