Mucous fiber

Topical anesthetics temporarily inhibit the conduction of impulses from sensory nerve fibers. These drug s may be used to relieve itching and pain due to skin conditions, such as minor bums, fungus infections, insect bites, rashes, sunburn, and plant poisoning, such as poison ivy. Some are applied to mucous membranes as local anesthetics. Examples of local anesthetics include benzocaine (Lanacane), dibucadne (Nupereainal), and lidocaine (Xylocadne). 

Some of tlie salts of bismuth are used in medicines for the relief of digestive disorders because of the smooth, protective coating the compounds impart to imtated mucous membranes. Like barium, bismuth also is used as an aid in x-ray diagnostic procedures because of its opacity to x-rays. At one time, certain bismuth compounds were used in the treatment of syphilis. Bismuth oxychloride, which is pcarlcsccnt, has found use in cosmetics, imparting a frosty appearance to nail polish, eye shadow, and lipstick, but may be subject to increasing controls. Bismuth phosphomolybdate has been used as a catalyst in the production of acrylonitrile for use in synthetic fibers and paints. Bismuth oxide and subcarbonate are used as fire retardants for plastics. 

Many substances of widely different chemical structure abolish the excitability of nerve fibers on local application in concentrations that do not cause permanent injury and that may not affect other tissues. Sensory nerve fibers are most susceptible, so that these agents produce a selective sensory paralysis, which is utilized especially to suppress the pain of surgical operation. This property was first discovered in cocaine, but because of its toxicity and addiction liability, it has been largely displaced by synthetic chemicals. The oldest of these, procaine (novocaine), is still the most widely used. Its relatively low toxicity renders it especially useful for injections, but it is not readily absorbed from intact mucous membranes and is therefore not very effective for them. Many of its chemical derivatives are also used. They differ in penetration, toxicity, irritation, and local injury as well as in duration of action and potency. Absolute potency is not so important for practical use as is its balance with the other qualities. If cocaine is absorbed in sufficient quantity, it produces complex systemic actions, involving stimulation and paralysis of various parts of the CNS. These are mainly of toxicological and scientific interest. Its continued use leads to the formation of a habit, resembling morphinism. This is not the case with the other local anesthetics. 

All local anesthetics including cocaine paralyze the nerve fibers anywhere in their course, wherever they are brought into contact with them. When applied to mucous membranes or hypodermically, they select the portions peripheral to the main trunks, the thinner sheath of the terminal fibrils facilitating its penetration. It is therefore unnecessary to assume selective action on the histological sensory endings. 

Figure 3.14. Structure of the stomach. Stomach contains four layers, including the mucosa, submucosa, muscularis, and serosa. The inner infolded mucous layer is made up of columnar epithelium, and gastric pits are found within the infoldings. Submucosa contains connective tissue and vessels, and the muscularis contains muscle fibers. The serosa is on the outside of the stomach and is continuous with the peritoneum.

VIP-immunoreactive fibers are found within the smooth muscle and in association with vessels and mucous glands (Dey et al., 1981 Ghatei et al., 1982 Laitinen et al., 1985 Springall et al., 1988). In some mammalian species, VIP has been localized to nerves running beneath the epithelium, though these subepithelial fibers appear to be of sensory origin (Barnes etal., 1991). The presence of VIP in the airways has been confirmed by measurements of the VIP content of extracts of airway tissue (Ghatei et al., 1982, 1983). 

Because of its sweet taste sucrose is consumed in large amounts. The perception of sweetness is mediated by taste buds submerged in the tongue and oral mucous membranes. The taste bud, a pear-like organ, consists of sensory cells (taste cells) interwoven with a branching network of nerve fibers. The taste bud contains two additional cell types basal and supporting cells. Sensory cells have a short life span of about 10 days, and new cells are derived from basal cells that continually undergo mitosis. Sensory... 

ACUTE HEALTH RISKS irritation to eyes, skin, throat, and upper respiratory system inert materials such as wood dust and polypropylene fibers may create mild irritant effects or act in combination with other irritants to enhance adverse clinical effects in humans and animals may cause swelling, redness and pain at site of mucous membranes tachypnea wheezing, and coughing occurs in 25% of inhalation irritant exposures inhalation exposure may result in pulmonary edema nausea vomiting and diarrhea are possible skin redness, swelling and pain may occur, but there should be no dermal erosions. 

The brain itself is almost totally insensitive to pain. The scalp, arteries, muscles, mucous membranes of the sinuses, ear, and the teeth are all pain-sensitive structures. The crucial areas in the creation of headache are the suboccipital and upper cervical areas as well as the scalp. In the upper two cervical segments, the sensory fibers of the first three cervical segments are joined by the descending tracts of cranial nerves V, IX, and X. These three cranial nerves, along with the second cervical nerve, mediate the referral of excessive coimective tissue tension in the cervical area as pain in the cranial vault or cephalgia. 

Soothing of gastrointestinal irritation—Mucilagenous types of fiber, such as the water-dispersible gums present in psyllium seed, okra, carob, and quince seed, coat and soothe irritated areas, particularly mucous surfaces. 

In vivo fiber-based spectroscopic analysis of tissues has been shown to offer a valuable tool to orient and facilitate medical diagnostics [169,170]. Hocde et al. used FEWS to identify metabolic alterations in laboratory animals [136]. For this the authors compared the spectral trace of biological fluid serums extracted from the blood samples of healthy and obese mice. FEWS has been successfully used to control in real time the glucose levels of human patients after they received intravenous glucose injections [171]. Noninvasive measurements were performed through the mucous membrane of the lips of a patient, a promising result for diabetes control. Similar FEWS in vivo measurements have been carried out on anesthetized live animals for premature tumor detection [167]. 

Uemura T., Nishida K., Sakakida M., Ichinose K., Shimoda S., and Shichiri M., Non-invasive blood glucose measurement by Fourier transform infrared spectroscopic analysis through the mucous membrane of the lip Application of a chalcogenide optical fiber system. Front. Med. Biol Eng., 9,137-153(1999). 

Toxicology Skin and mucous membrane irritant on repeated contact Kieralon TX-199 [BASF/Fibers ]... 

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