Buccal cavity

Toubeau G Cotman C. and Bels V. (1994). Morphological and kinematic study of the tongue and buccal cavity in the lizard Anguis fragilis. Anat Rec 240, 423-433. 

A paste of the proper consistency adheres to the tongue or buccal cavity and is not readily dislodged. The animal will eventually end up swallowing it. Characteristics of a suitable paste formulation are [17] ... 

Absorption from the buccal cavity has been shown to follow exactly the same principles as those described for absorption from the stomach and intestine. The pH of human and canine saliva is usually about 6. Bases in people are absorbed only on the alkaline side of their pK, that is, only in the nonionized form. At normal saliva pH, only weak bases are absorbed to a significant extent. 

Manning AS, Evered DF (1976) The absorption of sugars from the human buccal cavity. Clin Sci Mol Med 51 127-132... 

Sadoogh-Abasian F, Evered DF (1979) Absorption of vitamin C from the human buccal cavity. Br J Nutr 42 15-20... 

That derivatization may increase rather than decrease peptidase-catalyzed degradation is illustrated with aspartame (6.79, R = MeO), the C-terminal methyl ester of the dipeptide Asp-Phe. The metabolism of this artificial sweetener was compared to that of the underivatized dipeptide (6.79, R = H) and of the corresponding amide Asp-Phe-NH2 (6.79, R = NH2) in microvillar membranes obtained from human duodenum, jejunum, and ileum [189]. The activities monitored were clearly those of peptidases as shown by the effects of inhibitors. Whereas the peptide bond in Asp-Phe and Asp-Phe-NH2 was hydrolyzed at a comparable rate, that in aspartame was hydrolyzed approximately twice as fast. This is an interesting and favorable situation, given that aspartame is expected to be degraded once it has elicited its effect in the buccal cavity. 

Food is taken into the buccal cavity, where it is masticated by the teeth and mixed with saliva from three pairs of salivary glands. It moistens the food and dissolves some molecules enabling them to interact with the taste receptors on the tongue. Saliva contains Na% Cl and HCOs ions and a protein, mucin, which is a component of mucus that lubricates the chewed food on its way down the oesophagus. The pH of saliva is about 7.8, which neutralises acid formed by bacteria in the mouth this protects tooth enamel... 

The stomach receives food from the buccal cavity, it partially digests protein, fat and carbohydrate and it then delivers the resulting mixture (chyme) into the small intestine. The inner surface of the stomach is folded into ridges, to allow for distension after a meal, they contain gastric pits into which several gastric glands discharge their secretions (Table 4.1). 

A case control study of four plants where DMF was produced or used showed no statistically significant association between ever having been exposed to DMF and subsequent development of cancers of the buccal cavity and pharynx, liver, prostate, and testes and malignant melanoma. Although prostate cancer was significantly elevated at one plant when examined by plant site, it did not appear to be related to exposure level or duration. 

Certain vasodilators (like nitroglycerine) and hormones which can penetrate the buccal mucosal wall will only be kept in buccal cavity or under the tongue. It provides rapid onset of action and prevention of gastrointestinal interactions. 

One pair of epipharyngeal sensilla located in the buccal cavity completes the set of contact chemoreceptors in lepidopterous larvae. In P. brassicae larvae, each of these... 

The ergot alkaloids are variably absorbed from the gastrointestinal tract. The oral dose of ergotamine is about 10 times larger than the intramuscular dose, but the speed of absorption and peak blood levels after oral administration can be improved by administration with caffeine (see below). The amine alkaloids are also absorbed from the rectum and the buccal cavity and after administration by aerosol inhaler. Absorption after intramuscular injection is slow but usually reliable. Bromocriptine and cabergoline are well absorbed from the gastrointestinal tract. 

The internal environment of the gastrointestinal tract varies throughout its length, particularly with regard to the pH. Substances taken orally first come into contact with the lining of the mouth (buccal cavity), where the pH is normally around 7 in human, but more alkaline in some other species such as the rat. The next region of importance is the stomach, where the pH is around 2 in human and certain other mammals. 

Chen et al. (1988b) evaluated mortality in 1950-82 in the same cohort among both active and pensioned employees. Expected numbers (adjusted for age and time period) were based on company rates. For all workers exposed to dimethylformamide only, the standardized mortality ratios (SMR) were [0.9] (38 obs./40.1 exp.) for all cancers combined, [2.5] (2 obs./0.8 exp.) for buccal cavity and pharynx and [1.4] (19 obs./13.5 exp.) for lung cancer. No other cancer excesses were reported. 

A cohort study at two plants producing ethanol and isopropanol in the United States showed nonsignificant excess risks based on two cancers of the larynx and three buccal cavity and pharynx cancers in strong-acid workers (lARC, 1992a). 

As described in the monograph on diethyl sulfate (see this volume), a cohort study at an isopropanol and ethanol manufacturing plant in the United States revealed an increased risk for laryngeal cancer. As also mentioned in the same monograph, a cohort study at a plant producing ethanol and isopropanol in the United States suggested an increased risk for cancers of the larynx, buccal cavity and pharynx in strong-acid workers (lARC, 1992). 

For example, intestinal motility moves material in the stomach or small intestine distally towards the large intestine it has been estimated that in some cases residence of a drag in the small intestine can be in the order of minutes. In the buccal cavity, the administered dosage form is washed daily with 0.5-2 litres of saliva. 

The oral cavity offers a relatively large surface area (the total area of the buccal cavity is approximately 100 cm2) for drag absorption. 

The highly vascular surface of the oral mucosa ensures rapid absorption and onset of action, as well as the maintenance of sink conditions. In particular, the sublingual route is characterized by a rapid onset of action. The buccal cavity offers the combined advantages of a relatively rapid onset of action, with the potential for sustained delivery over several hours. 

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