BEHAVIOR PATTERNS OF THE ALIMENTARY TRACT*

T. WINGATE TODD, F.R.C.S. ENC,.

CLEVELAND. OHIO

D 1 JRING the past five xenrs, with the active cooperation of our medica students an d ns a part of the

ordinary course of Anatomy, Miss W. M. KuenzeI and I have been conducting a series of demonstrations on the gastric and colonic behavior patterns. The advantage of tfris method of teaching is sufficiently obvious in that it transforms the Iaboratory into a clinic for the study of normal organs in their healthy acti\-ity. It certainIy calls for more constant and assiduous attention on the part of the instructor but since it binds research and teaching closeI> together it provides a training for the student of the finest possible type and enlarges the experience of the instructor himself in an intenseIy practical manner.

While one may appIy to Man the general principles deduced from investigation upon lower mammaIs, detailed information regarding the structure and function of the human body can be obtainecI onIy by a study of Man himself. I wiI1 content myself here with a brief statement concerning the principal features of our study.’

In order to obtain organs which can be

depended upon to function without inter- ference by refIeses cf central origin we finc1 it necessary to put our students through a careful training in which they came to realize the significance of the roentgenographic and fluoroscopic methods of approach. By thus training and stabili- zing the stomach and colon we tind we can eIicit definite and characteristic responses to a variety of stimuIi, and, as a resuIt of our enden\-ors, we hope to supersede the present rough and undiscriminating

1 ‘The extcndcd results of our invcstiption are now

methods of clinical examination of the alimentary tract.

So far as our coIonic studies ha\-e pro- gressed we are still [earning the method of stabiIizing the bowe1 which is quite as sensitive as the stomach to extrinsic stimuIi and even more refractory-. In fact the coIon forms a reIiable index of sub- conscious mental strain or escitement, So easily is it thrown out of action that the mere fact of undergoing a fIuoroscopic examination reduces or inhibits the regular peristaltic contractions of the proximal coIon and may bring about a spastic condition. The stabiIized proximall coIorr howe\,er shows a peristaItic activity onI! slightly less vigorous than that of the stomach. Roentgenograms taken at inter- I-als of three seconds show this quite c*learl>- and it is also obvious on the fIuoro- scopic screen. For the cIearest presentation of colonic activity a Iarge opaque mea1 is necessary, say 12 oz. of buttermiIk with 4 oz. of barium suIphate. The best results are obtained in Sophomores in October, after a year of training in Anatomy and roentgenoscopic technique ancI before the stress of the winter’s studies have modified the norma heaIthy functioning of the bowel.

The coIonic activity observed, is :I reguIar katastaIsis of a rhythm somewhat slower than gastric katastaIsis but just as regular. We have never seen either anastal- sis or peristaltic rush though we do not mean to infer that these phenomena do not exist in Man. Indeed a \rery rapid massi\.e contraction of the dista1 colon must occur to bring about defecation. We do h[owever fee1 that both phenomena are present onI\ occasionally.

Our gastric studies are far more ad- lanced. So far we ha\:e investigated the

response ofthe stomach to milk, buttermiIk, \vater, lactic acid, heat, cold and the intro- duction of a foreign body, namely a rubber balloon.

Milk, buttermilk and lactic acid each calls forth a secretion of gastric juice which causes Iateral distention of the stomach. This distention is less pronounced after milk than after buttermiIk and is still less marked after lactic acid. Water, which does not stimulate this secretion of gastric juice, produces no Iuteral distention. The water stomach however presents very active peri- stalsis which would be invoked as the de- termining cause of the rapid passage of the water mea1 through the pylorus but forthe fact that, after milk, we observe passage of barium through the pylorus in the absence of peristaitic waves.

A buffered lactic acid of pH, induces a peristalsis almost indistinguishable from that of buttermilk. Both fluids call forth ;I massive wave of considerabIe amplitude and frequencv, vvhich almost nips the bari- um shadow in two in the pyloric canal. The actua1 rate of progress of the lactic wave is slightly slower than that of butter- milk which, in its turn, is slower than the milk wav’e.

Milk induces a less active peristaIsis than the other fluids. Waves are of smaIler amplitude and frequency, are not so obvi- ous in the gastric tube and tend to break down into random and purposeless wavelets defined by us as shimmer. Curiously enough the area of shadow after a miIk meal is smaller than that following a buttermilk meal of the same amount.

For our gastric experiments we empIoy a $ oz. meal, consisting of 4 oz. of vehicle

to which are added 33 gm. of barium sulphate because this smal1 amount is com- pletely or practically passed on through the pyIorus within an hour.

The effects of heat and coId on the stomach are more pronounced by appiica- tion of hot bag or cold pack to the abdomi- nal waI1 than by the administration of a hot (I~o’F.) or a cold (32’~.) meal. Heat to abdominal wall for a period of forty-five minutes fIefore the swallowing of a regular opaque milk meal at ROOF. evokes a short narrow shadow of small area with intense peristaltic activity sustained over some twenty minutes. Cold under like circumstances produces much less effect on size of shadow and the peristaltic activity, though vigorous at first, is rapidly reduced and may be negligible after between five and eight minutes.

A rubber bag in the stomach caIIs forth one of several types of response. There may be marked secretion of gastric juice, intense ballooning of IMagenhlase or ev-en diaphragmatic flicker.

We have reason to beIieve that the dif- ference between buttermilk and milk re- sponses is related to the presence of lactic acid in the former.

In the irritable stomach we find the milk pattern as active as that of buttermilk. In the harassed stomach associated with marked mentaI anguish we find that even buttcrmirk fails to produce a v,igorous peristalsis.

It is our intention to pursue these studies further for the purpose of analyzing more fully the physiological activity of the ali- mentary tract.