A text-book of materia medica, therapeutics, and pharmacology / by George Frank Butler.

Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of materia medica, therapeutics, and pharmacology / by George Frank Butler. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the vagus, increasing the blood-supply to the gastric glands and thereby promoting their functional activity. When the bitters have been swallowed, an increased secretion ensues, occasioned by direct stimulation of the mucous mem- brane of the stomach. Through the sen- sory fibers of the vagus the impression is conveyed to the center in the medulla, returning by the vaso-motor and secretory fibers, and increasing the functional activity of the glands. This action is well shown in the diagram (Fig. 2). When too large a dose of bitters has been taken, or under prolonged medicinal dosage—when contraindicated by an irri- table stomach—the effects are a diminished secretion of gastric juice and a corre- sponding increase in the secretion of mucus. This effect of over-stimulation or irritation is well illustrated in persons addicted to the excessive use of alcohol, a moderate amount promoting the secretion of gastric juice and improving the appetite, while excess occa- sions nausea and the vomiting of glairy mucus. The theory governing the above action is that a medicinal dose of bitters is just sufficient to stimulate the functional activity of the gastric glands, but that immoderate or continuous dosage tends to convey the impression farther up in the medulla, causing stimulation of the vaso-constrictor fibers, con- tracting the blood-vessels, and lessening the blood-supply and the secretion from the glands. At the same time the secretory fibers supplying the mucous cells are stimulated, causing an increased secretion of mucus. Should the dose be sufficiently large to pro- duce vomiting, the action is due to the fact that the impression is conveyed still higher in the medulla, and from there transmitted to the nerves supplying the abdominal walls and diaphragm, the effect being to produce emesis. The diagram (Fig. 3) graphically illustrates this action. III. Bitters stimulate the peristaltic movements of the stomach by reflex action. The sensory nerves in the mucous membrane are Fig. 2.—Diagram illustrating the action of bitters on the gas- tric secretion: A, medulla; B, stomach ; C, gland ; D,D, blood- vessels supplying the gland; E, nerves of taste; i, vaso-motor fibers ; 2, secretory fibers ; 3, sen- sory fibers.