A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron).
Afferentnerves convey sensory signals to the central nervous system, for example from skin or organs, while efferent nerves conduct stimulatory signals from the central nervous system to the muscles and glands.
Nerve damage or pinched nerves are usually accompanied by pain, numbness, weakness, or paralysis.
In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system.
The structure of an afferent neuron contains a single long dendrite and a short axon; the shape of the cell body of an afferent neuron is smooth and rounded.
Just outside the spinal cord, thousands of afferent neuronal cell bodies are aggregated in a swelling in the dorsal root known as the dorsal root ganglion.
This means that the same nerve fibers are reporting the state that underlies the desire to urinate or defecate and the sensation underlying the pain felt when these organs are strongly contracting in an attempt to evacuate their contents.
The stimulus-specific organization of the peripheral nerve fibers is not continued within the spinal cord, as the various afferentnerve fibers do not transmit their impulses exclusively to neurons of only one kind of sensibility.
A volley of nerve impulses reaching the brain via the spinothalamic and spinoreticular tracts and causing a moderate degree of pain is stopped when the cells of origin of this tract are inhibited.
When a nerve is stimulated sufficiently distal to the spinal cord, the depolarization of the dorsal horn neurons occurs sequentially as a function of the arrival of afferents with different conduction velocities.
The rationale behind the CDP measurement as an assessment of sensory nerveafferent and dorsal horn neuronal functions is the phases of the CDP reflect the different population of afferent fibers activating dorsal horn neurons (Yates et al., 1982; Yates et al., 1985).
The length of phrenic nerve was measured from the stimulating electrodes to the dorsal root entry zone to calculate the conduction velocity of the phrenic nerveafferents.
www.biomedcentral.com /1472-6793/5/7 (4690 words)
Effect of GABAB receptor agonist on distension-sensitive pelvic nerve afferent fibers innervating rat colon -- Sengupta ...(Site not responding. Last check: 2007-11-03)
Contribution of C-fiber afferentnerves and autonomic pathways in the urinary bladder to spinal c-fos expression induced by bladder irritation.
Characteristics of mechanosensitive pelvic nerveafferent fibers innervating the colon of the rat.
Characteristics of mechanosensitive pelvic nerveafferent fibers innervating the urinary bladder of the rat.
Auditory System: Anatomic Tour(Site not responding. Last check: 2007-11-03)
The auditory nerve enters the brain stem at the ponto-medullary junction and synapses on the ipsilateral cochlear nucleus.
The auditory nerve is made up of approximately 30,000 nerve fibers with afferent (sensory) portions projecting from cell bodies in the spiral ganglion and efferent axons coming from cells in the olivary complex.
The afferent neurons are divided into Type I and Type II fibers based on their morphology.
Histamine sensitivity of mesenteric afferent nerves in the rat jejunum -- Kreis et al. 275 (4): 675 -- AJP - ...(Site not responding. Last check: 2007-11-03)
Histamine sensitivity of mesenteric afferentnerves in the rat jejunum -- Kreis et al.
8 µmol/kg evoked a dose-dependent increase in afferentnerve discharge
nerve discharge that was typically biphasic at a dose of 8 µmol/kg.
British Journal of Pharmacology - Inhibition of mechanical activation of guinea-pig airway afferent neurons by ...(Site not responding. Last check: 2007-11-03)
The aim of the present study was to investigate a role for ENaCs and the epithelium in the mechanical activation of low-threshold vagal afferentnerve terminals in the guinea-pig trachea/bronchus.
Guinea-pig airway vagal afferent fibres whose cell bodies reside in nodose ganglia and whose receptive fields are located in the trachea respond in a rapidly adapting manner to punctate mechanical stimuli or increases in intraluminal tracheal pressure as described previously (McAlexander et al., 1999).
Electrical threshold for activation of afferentnerve terminals was expressed in terms of a fold increase of the voltage required to evoke action potentials.
Synergistic interactions between airway afferent nerve subtypes mediating reflex bronchospasm in guinea pigs -- Mazzone ...(Site not responding. Last check: 2007-11-03)
The majority of the capsaicin-sensitive afferentnerves are C-fibers and project to the larynx and adjacent portions of the trachea via SLNs (see Ref. 8).
The necessity of the laryngeal and the intrapulmonary afferentnerve inputs for mediating reflexes evoked from the larynx
Identity of the afferentnerve fibers mediating reflex bronchospasm evoked from the larynx.
Before describing which afferentnerve fibers are involved in reflex coughing, it seems appropriate to first provide a brief overview of the various afferentnerve subtypes that have been described in the mammalian airways.
Regardless of the afferent fiber, the majority of airway afferentnerves originate in the vagal sensory ganglia (nodose or jugular) [13,14].
A small population of fibers (believed to be a subpopulation of chemosensitive nerves) may have their origin in dorsal root ganglia adjacent to the upper thoracic spinal cord [15].
www.coughjournal.com /content/1/1/2 (5059 words)
Visceral afferent activation-induced changes in sympathetic nerve activity and baroreflex sensitivity -- Saleh et al. ...(Site not responding. Last check: 2007-11-03)
nerve branch was isolated from the surrounding tissue.
Projections from buffer nerves to the nucleus of the solitary tract: an anatomical and electrophysiological study in the cat.
The central distribution of the cervical vagus nerve and gastric afferent and efferent projections in the rat.
The Autonomic Nervous System(Site not responding. Last check: 2007-11-03)
The efferent nerve fibers of the ANS are often referred to as secreto-motor neurons, since stimulation of the organs they innervate often results in secretion (by glands) and/or movement (of smooth muscle).
Most of the body’s parasympathetic innervation is controlled through preganglionic fibers that arise from four different cranial nerves and synapse on postganglionic fibers in various ganglia located on or near their target organ.
Preganglionic fibers of the dorsal nucleus of the vagus synapse on postganglionic nerves in a variety of ganglia in the thoracic and abdominal region.
The Role of Vagal Afferent Nerves in Chronic Obstructive Pulmonary Disease -- Undem and Kollarik 2 (4): 355 -- ...(Site not responding. Last check: 2007-11-03)
nerves in the lungs are vagal afferentnerves.
Functional and histological studies of the vagus nerve and its branches to the heart, lungs and abdominal viscera in the cat.
Afferent vagal C fibre innervation of the lungs and airways and its functional significance.
c-Fos expression in the central nervous system elicited by phrenic nerve stimulation -- Malakhova and Davenport 90 (4): ...(Site not responding. Last check: 2007-11-03)
Phrenic nerveafferents (PNa) have been shown to activate neurons in the spinal cord, brain stem, and forebrain regions.
nerve was physiologically identified by movement of the diaphragm
Convergence of visceral and somatic afferents on single neurons in the reticular formation of the lower brain stem in dogs.
Prevention of High Incidence of Neurally Mediated Ventricular Arrhythmias by Afferent Nerve Stimulation in Dogs -- Zhou ...(Site not responding. Last check: 2007-11-03)
The left peroneal nerve was isolated 1 to 2 cm along its length.
of coronary circulation to the ventricles caused by afferent
Effects of peroneal nerve stimulation on hypothalamic stimulation-induced ventricular arrhythmias in rabbits.
Selective stimulation of jugular ganglion afferent neurons in guinea pig airways by hypertonic saline -- Pedersen et ...(Site not responding. Last check: 2007-11-03)
afferent neurons in guinea pig airways by hypertonic saline.
A: effect of hypertonic saline on afferent vagal nerve activity in guinea pig trachea and main stem bronchus.
of nerves mediating the increase in vascular permeability.
Posterior tibial nerve stimulation (PTNS) is a technique of electrical neuromodulation for the treatment of voiding dysfunction in patients who have failed behavioral and/or pharmacologic therapies.
While the posterior tibial nerve is located near the ankle, it is derived from the lumbar-sacral nerves (L4-S3) which control the bladder detrusor and perineal floor.
This device was cleared as a class II ‘‘nonimplanted, peripheral nerve stimulator for pelvic floor dysfunction” because it was considered to be substantially equivalent to the previously cleared percutaneous Stoller afferentnerve system (PerQ SANS System) in 2001 (K992069, UroSurge, Inc.).
