The Croonian lectures on the chemical correlation of the functions of the body : delivered before the Royal College of Physicians of London on June 20th, 22nd, 27th & 29th, 1905 / by Ernest Henry Starling.

  • Ernest Starling
Date:
[1905?]
Catalogue details

Licence: Public Domain Mark

Credit: The Croonian lectures on the chemical correlation of the functions of the body : delivered before the Royal College of Physicians of London on June 20th, 22nd, 27th & 29th, 1905 / by Ernest Henry Starling. Source: Wellcome Collection.

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    -22 succus entericus—namely: (1) the mechanical distension of the intestinal canal; and (2) the presence of pancreatic juice. He found that a flow ot succus entericus could be more easily evoked by the introduction of a ‘small amount of fresh pancreatic juice into the intestine than by any other means, and work by his pupils seems to point to the richness of the juice in enterokinase being proportional to the amount of pancreatic juice introduced into the canal. If these observations be correct, they would point to the trypsinogen, or some associated substance in the pancreatic juice, as being itself the chemical stimulant for the glands of the intestinal wall. Whether this chemical irritant acts directly, or whether it reaches the follicles of Lieberkihn by way of the blood stream, is as yet undetermined. Since it is the trypsinogen which needs the pre- sence of enterokinase, it would be natural to assume that this substance itself is the actual stimulant of the intestinal glands. A somewhat different view of the exciting agent for the intestinal secretion has been put forward by Délézenne. This observer, working on dogs with intestinal fistule at various regions of the gut, obtained practically no secretion except from the uppermost section—namely, that including the duodenum. He finds that the secretion of what we may call duodenal juice, which must be succus entericus together with a small amount of the secretion of Brunner’s glands, is excited simultaneously with the pancreatic juice and the bile by the injection of secretin into the blood stream. According to this observer, therefore, the secretion of the three cooperating juices in the upper part of the small intestine—namely, bile, pancreatic juice, and succus entericus containing enterokinase—is brought about by one and the same mechanism—namely, the production of secretin in the intestinal mucous membrane under the influence of the entry of the gastric contents. It is, however, only in the upper part of the gut that the chief réle of the succus entericus can be regarded as adjuvant to the pancreatic juice, and it is only here that the intestinal juice con- tains any large quantity of enterokinase. Lower down in the gut a secretion of alkaline intestinal juice is still of importance in consequence of its content in (a) sodium carbonate for the neutralisation of the organic acids produced in the changes in foodstuffs ; (b) the ferment erepsin which breaks down the products of gastric and pancreatic digestion of proteids, converting albumoses and peptones into the nitrogenous end-products, amino-acids, and nitrogenous bases; and (c) the ferments invertase and maltase which complete the digestion of the carbohydrates of the food. To these two ferments we must, in the case of milk-fed animals, add the ferment lactase, in the absence of which milk sugar is incapable of undergoing assimilation. According to Frouin the secretion of succus entericus (apparently in the middle part of the small intestine) can be evoked by the intravenous injection of succus entericus itself or by an extract of the intestinal mucous membrane. It is difficult to see the teleological significance of such a mechanism, unless we assume that some constituent of the succus enteri- cus, produced by the mechanical stimulation of the foodstuffs themselves,
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