Mechanism Of Defecation Research Articles

X-ray cinematographical observation on the defecation mechanism

X-ray cinematographical observation on the defecation mechanism

Studies on the defecation relfex in man.

In patients with cecostomies and in patients with urinary bladder substitutes obtained from either the sigmoid colon or the cecum, the motor activity in different parts of the large bowel was recorded with the aid of open tip tubes and a pressure-recording apparatus after administration of a contact laxative (Dulcolax®). Administration of Dulcolax® into the cecum of patients with cecostomy produced motor activity locally as well as in the transverse colon and in the sigmoid. When the drug was administered into the cecum of patients with isolated cecal bladder replacements, motor activity was recorded in the cecum but not in the sigmoid. Rectal application of Dulcolax® initiated motor activity in the intact sigmoid as well as in the isolated sigmoid bladder substitute but not in the cecum in patients with cecostomies nor in the cecal bladder replacements. The experiments indicate that only the left colon is engaged in the defecation mechanism elicited by rectal stimulation. The motor response in the left colon after rectal stimulation is mediated by a reflex with its afferent limb from the rectal ampulla. The motor response in the sigmoid after cecal stimulation is elicited by impulses mediated by intrinsic nervous pathways in the intestinal wall.

Photo-optical observations on the mechanism of defecation in man

Photo-optical observations on the mechanism of defecation in man

90. Studies on Autonomic Reflex Mechanism of Defecation with Special Aspect of the Rectoampullometry

90. Studies on Autonomic Reflex Mechanism of Defecation with Special Aspect of the Rectoampullometry

The rehabilitation of patients totally paralyzed below the waist, with special reference to making them ambulatory and capable of earning their own living. IV. Control of bowel emptying.

REHABILITATION to any practical extent is impossible for a patient with a spinal-cord or cauda-equina injury unless he can be certain that he can have infallible control of his bowel under ordinary circumstances and that, as a result, he need not fear soiling himself unexpectedly.This desirable condition depends upon the establishment of a conditioned reflex as the result of which the large bowel empties itself only at certain prearranged times.It is necessary to know the normal physiologic anatomy of the bowel as well as the mechanism of normal defecation to understand how such a reflex can be effectively . . .

TONUS OF THE VOLUNTARY ANAL AND URETHRAL SPHINCTERS

THE TERM tonus applied to skeletal muscle is gradually disappearing from use. Sherrington's summation at the conclusion of the International Neurological Congress in 1931 1 indicated the present day concept of skeletal muscle tonus as purely a simpler form of contraction activated largely by proprioceptive reflexes. However, the term is still retained with reference to the activity of the striated muscles forming the voluntary anal and urethral sphincters. In describing the mechanism of defecation, Cowgill 2 stated that ... both the internal and external sphincter are normally in tonus. Denny-Brown and Robertson, 3 in their study of micturition, stated that it is only when vesical contraction has commenced and has reached a degree sufficient to be accompanied by opening of the internal sphincter that relaxation of the tone of the external sphincter, sufficient to allow the passage of fluid, occurs. Hoefer 4 showed that the normal striated muscles of the extremity

TECHNIC OF REPAIR OF ENTEROCELE (POSTERIOR VAGINAL HERNIA) AND RECTOCELE

The subject of this paper is limited to hernias involving the posterior vaginal wall, which we frequently encounter and recognize under the designation of rectocele, and to the much rarer hernia which is made up of the culdesac of Douglas, with its intestinal contents dissecting its way downward between the posterior vaginal wall and the rectum, known as vaginal enterocele or posterior vaginal hernia. The common condition of rectocele is the result of impairment of the function of the pelvic floor (the inability to properly close the vaginal mouth), due to injury in childbirth, thus allowing the vaginal wall to roll downward and outward with the attached rectum. This anatomic change in the relation of the parts alters the normal mechanism of defecation, the direction of the fecal current being changed so that the anterior rectal wall and the posterior vaginal wall receive the brunt of the strain and, consequently,

A FURTHER CONTRIBUTION TO THE STUDY OF THE DIFFICULTIES OF DEFECATION IN INFANTS.

At last year's meeting of this Section I offered for inspection a score of dried specimens of the infant's lower intestine as evidence that the infant strains at stool because of the imperfect development of the anatomic features concerned in the mechanism of defecation. Examination of those specimens revealed the fact that the wall of the infant rectum and sigmoid flexure is thin, compared to that of the adult. It was impossible to distinguish the longitudinal muscular bands which are so apparent in the gut of the adult. It was observed that in the fresh state the mucous membrane constitutes a greater part of the gutwall of the infant, and that the mucous membrane and muscular coats are more intimately adherent than in the adult. The infant gut being very deficient in muscular elements, the intrinsic power of peristalsis can not be present in that degree necessary to it as