Mucus consistency

The dendrites on the receptor cells have swellings, the olfactory knobs. These knobs have smooth vesicles that may be open to the mucus covering the epithelium. From each knob extend 1 to 150 cilia, floating in the mucus. The precise number of cilia varies with the species. The rabbit, for example, has 10-12 cilia on each knob. The surrounding mucus consists of mucopolysaccharides, lipids, and phosphatides. The axons of the olfactory receptor cells extend through the cribriform plate and terminate in the olfactory bulb (Fig. 5.1). 

Nasal mucus. The nasal mucus protects the body against airborne substances. Nasal mucus consists of mucopolysaccharides complexed with sialic acid, sloughed epithelial cells, bacteria, water (95 percent), glycoproteins and lipids (0.5 to 5 percent), mineral salts (0.5 to 1 percent), and free proteins (albumin, immunoglobulins, lysozyme, interferon, lactoferin, etc., 1 percent).13 45 111 112 The surface pH of the nasal mucosa is 5.5 to 6.5.113... 

In higher organisms epithelia are covered by a protective gel layer defined as mucus. By weight, mucus consists mainly of water (95-99.5%) in which the mucous glycoprotein mucin (0.5-5 /o) is dispersed. Mucins are the major components responsible for the gel-like structure of the mucus. They possess a linear... 

The nasal epithelium contains cells with or without cUia, mucous cells and basal cells. The submucosa contains glands that produce mucus and an aqueous secretion. Nasal mucus consists of 95 % of water and contains 2 % mucine, 1 %... 

After administering the drug, the nurse notes any increase in sputum or change in consistency. The nurse documents, on the patient s chart, a description of the sputum raised. Fhtients with thick, tenacious mucus may have difficulty breathing. It is important to notify the primary health care provider if the patient has difficulty breathing because of an inability to raise sputum and clear the respiratory passages. 

FIGURE 1119 The lysozyme molecule is a typical enzyme molecule. Lysozyme is present in a number of places in the body, including tears and the mucus in the nose. One of its functions is to attack the cell walls of bacteria and destroy them. This "ribbon" representation shows only the general arrangement of the atoms to emphasize the overall shape of the molecule the ribbon actually consists of amino acids linked together (Section 19.13). 

V. cholerae is a gram-negative bacillus. Vibrios pass through the stomach to colonize the upper small intestine. Vibrios have filamentous protein extensions that attach to receptors on the intestinal mucosa, and their motility assists with penetration of the mucus layer.2 The cholera enterotoxin consists of two subunits, one of which (subunit A) is transported into the cells and causes an increase in cyclic AMP, which leads to a deluge of fluid into the small intestine.20 This large volume of fluid results in the watery diarrhea that is characteristic of cholera. The stools are an electrolyte-rich isotonic fluid, the loss of which results in blood volume depletion followed by low blood pressure and shock.2 Of note, the diarrheal fluid is highly infectious. 

Meconium The first intestinal discharge or stool of a newborn infant, usually green in color and consisting of epithelial cells, mucus, and bile. 

The glycocalyx and the mucus layer make up the structure of the unstirred water layer (UWL) [73]. The thickness of the UWL is estimated to be 30-100 pm in vivo, consistent with very efficient stirring effects [74]. In isolated tissue (in the absence of stirring), the mucus layer is 300-700 pm thick [73]. The pH in the unstirred water layer is 5.2-6.2, and might be regulated independently of the luminal pH (Section 2.3). The mucus layer may play a role in regulating the epithelial cell surface pH [73]. 

Specimens should be examined grossly to determine the consistency (hard, formed, loose, or watery), color, and presence of gross abnormalities such as worms, mucus, pus, or blood. It may be profitable to examine flecks of mucus, pus, or blood for parasites. If adult worms or portions of tapeworms are sought, the feces may be carefully washed through a screen. (Small worms may be difficult to see if gauze is used.) The identification characteristics of adult worms are not discussed in this chapter, so parasitology books should be consulted. 

An increased incidence in mycoplasma infections in rats exposed to 260 ppm hexachloroethane for 6 weeks suggests that hexachloroethane might weaken resistance to infection (Weeks et al. 1979). This could be the result of either a change in the quantity or consistency of the respiratory tract mucus or a systemic weakening of the immune system. The data are inadequate to formulate any hypothesis regarding the mechanism for diminished host resistance or to postulate whether hexachloroethane in the environment might lower the resistance of humans to respiratory infections. 

Other Limitations The small intestine is a very dynamic environment the pH of the medium changes, the intestinal content is propelled by muscular contractions, food and xenobiotics are being digested by different enzymes and after absorption of compounds by the enterocytes, these compounds reach the blood vessels to be transported throughout the body. In contrast to the in vivo situation, the Caco-2 model is a static model consisting of one single cell type which is unable to secrete mucus. The unstirred water layer is thicker than the one in vivo and for some compounds it is difficult to work under sink conditions. 

Tensiometry Force required to dislodge two surfaces, one coated with mucus, the other solid dosage form consisting of mucoadhesive hydrogel... 

Oral mucosae are covered with mucus which serves as a link between the adhesive and the membrane. Mucus is a glycoprotein consisting of a large peptide backbone with pendant oligosaccharide side chains. The side chains terminate in sialic or sulfonic acids, L-fucose, sulfated galactose, or A -acetylglucosamine. The glycoprotein component imparts the viscous or gel-like (non-Newtonian) nature due to its capacity... 

Figure 7-2 illustrates a three-compartment structure assumed by McJilton et al. for describing radial diffusion. It consisted of a gas phase in the lumen of the airway, a liquid layer that lined the airway, and a tissue compartment. The rate of movement of the gas into the liquid layer, dm /dt is a function of the solubility of the gas in the liquid, as defined by the Henry s law constant. The rate of movement of the gas molecules across the liquid layer to the tissue compartment, dm /dt is a function of the diffusion co cient of the gas in the mucus and serous... 

Figure 4.2 Substructure of the wall in the gastrointestinal tract. (Not to scale). Epithelial cells of the villi possess micro villi which extend into the lumen (Not shown). The epithelium consists of absorptive enterocytes, endocrine cells that secrete peptide and goblet cells that secrete mucus.

Although pheromones can be considered as a special form of odorants (scents), their actions, effects and functions have similarities to those of hormones. They bind to a specific receptor which then activates an effector system, which initiates an action potential. They bind to specific sensory cells, the neurones, in the olfactory epithelium, which is located on the roof of the nasal cavities. The epithelium consists of three types of cells, basal, supporting and sensory cells (neurones). The neurones are bipolar, that is they possess a single dendrite, which extends from the cell body to the surface of the olfactory epithelium, and an axon that forms a synapse with a nerve that transfers information to the olfactory centre in the brain. The epithelium is covered with a thick layer of mucus, in which the pheromones dissolve. The mucus contains proteins that bind the pheromone(s) for delivery to the olfactory receptors and then to remove them once they have been detected. 

The endometrium consists of an epithelinm, the tunica propria, which contains glands that prodnce mucus, and the endometrial stroma. The latter is divided into the lamina basaUs and the lamina functionalis. It is much of... 

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