AUTHOR’S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, AUGUST 7 
NERVE ENDINGS OF SENSORY TYPE IN THE 
MUSCULAR COAT OF THE STOMACH AND 
SMALL INTESTINE 
PRELIMINARY NOTE 
F. W. CARPENTER 
Biological Laboratory of Trinity College, Hartford, Connecticut 
FOUR FIGURES 
A variety of visceral sensations are attributed by physiologists 
to impulses originating in the muscular coats of hollow organs. 
Such sensations of the alimentary canal as fullness and distension, 
emptiness and hunger, and especially pain, are believed to be due 
to the stimulation of sensory nerve endings lying, not in the 
mucous or submucous tunics, but in the coat of smooth muscle 
external to these. Much of the evidence for this view, based on 
physiological experimentation and clinical observations, is given 
by Hurst (’11) in his Goulstonian Lectures on ‘“The Sensibility 
of the Alimentary Canal.’ The cause of visceral pain receives 
particular consideration from this author, who regards tension 
on the fibers of smooth muscle to be the adequate stimulus for 
the sensation. His general conclusion is, indeed, that ‘tension 
is the only cause of true visceral pain.” 
The recent detailed investigations of Carlson and his co-workers 
on the physiology of the stomach tend to confirm the view that 
the nerve endings concerned in sensory impulses from this organ 
are to be sought in its muscular coats, although the submucosa 
is also recognized as a possible site of such endings. Carlson 
(13) concludes that the gastric sensory apparatus for hunger 
lies in the muscularis or in the adjacent connective tissue of the 
submucosa, but not in the mucosa. Carlson and Braafladt 
(15) find the normal gastric mucosa devoid of pain and tactile 
sensibility, and agree that “‘the literature seems to show that the 
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THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, NO. 5 
