An Introduction to Gastro–Enterology

The Mechanics of the Digestive Tract, Fourth Edition: An Introduction to Gastro-Enterology provides information pertinent to the mechanics of the digestive tract. This book reviews the various explanations for the downward progress of intestinal waves.

Organized into 34 chapters, this edition begins with an overview of the main types of activity in the small bowel. This text then explains the nature of the polarity and the location of the mechanism that produces it. Other chapters consider the duodenal tonus contraction in which the wave seems to originate generally appears a few seconds before a gastric wave reaches the pylorus. This book discusses as well the polarity of the bowel that caused every contraction ring to spread caudad as soon it formed. The final chapter provides a list of books that are likely to be helpful to readers who are starting on their lifework in the fields of gastro-enterology and gastro-intestinal physiology.

This book is a valuable resource for students, teachers, physicians, and research workers.

Preface to Fourth Edition

Preface to Third Edition

Preface to Second Edition

List of Illustrations

I. The Motor Functions Of the Small Bowel

Two Main Types of Activity

The Polarity of the Bowel

The Several Forms of Activity

Activity in the Small Bowel of Man

Effect of Sleep

Changes in the Irritability of the Bowel

The Metabolic Rate of the Intestinal Wall

Summary

II. The Facultative Autonomy of the Digestive Tract

Evolution of the Nervous System

The Function of the Nerves

Summary

III. Some Theories that have Been Advanced to Explain the Polarity of the Small Bowel

Bayliss and Starling's Law, or the Myenteric Reflex

The Normal Rush Waves

Keith's Theory of Intestinal Control

Carey's Theory

Goerttler's Idea

Summary

IV. The Gradient Theory of the Polarization of the Bowel

Definition of a Gradient

The Polarity of the Heart

Gradients in Several Tubular Organs

The Gradient in the Rate of Rhythmic Contraction of the Intestine

Is the Polarity or Gradient Located More in the Myenteric Plexus than in the Muscle

The Origin of Gradients in the Egg and the Embryo

The Polarity of the Bowel is Primarily "Built In"

Is the Gradient the Cause of the Polarity

Is There a Gradient in the Bowel of Man

History of the Idea of the Gradient

Summary

V. A Possible Basic Metabolic Gradient

A Metabolic Gradient

Gradients in Chemical Composition

Axial Gradients in Lower Forms of Life

Summary

VI. Other Related Gradients

Gradient in the Force Exerted by the Intestinal Muscle

Gradient in Anatomic Structure

Gradient in Ability to Withstand Distention

Chemical Gradients Along the Mucosa

Resistance of the Intestinal Mucosa to Gastric Juice

Gradient of pH in the Intestinal Contents

Summary

VII. Ways in Which a Gradient Might Conceivably be Altered or Reversed

Factors that Might Alter the Gradient

Reversal of Gradients by Drugs

Ways in which Various Factors Might Alter a Gradient

Intestinal Obstruction

A New Law of the Intestine

Dietary Suggestions

Summary

VIII. The Syndrome Of Reverse Peristalsis

Vomiting

Regurgitation

Heartburn and Distresses Confused with it

Belching

Nausea

Motion Sickness and Nausea

Coated Tongue and Bad Breath

Feeling of Fullness After Beginning to Eat

Hiccup

Biliousness

Difficulties and Objections

Summary

IX. The Smooth Muscle of the Gastro-Intestinal Tract

Anatomic and Physiologic Characteristics

Types of Smooth Muscle

Response to Tension

Response to Direct Irritation

Summary

X. The Muscular Versus the Nervous Origin of the Rhythmic Contractions of the Gut

The Work of Magnus

Can Intestinal Muscle be Denervated Mechanically

Studies with Tissue Cultures

Contractions in Embryonic Nerve-Free Intestinal Muscle

The Heart of Limulus

Rhythmic Activity a Property of All Contractile Tissue

Light Thrown by the Electrogram

Anoxemia as an Instrument for Analyzing Nervous Structures

Pharmacologic Arguments

Nervous Influences Affect the Rhythmic Contractions

Summary

XI. The Structure and Functions of the Myenteric Plexuses

Methods of Study

Histologic Studies

The Anatomy of the Plexuses in the Stomach

Origin of the Enteric Nervous System

Functions of the Myenteric Plexuses

Physiologic Studies to Determine the Structure of the Myenteric Plexus

Types of Conduction Along the Small Bowel

Conduction which Enables Thousands of Muscle Fibers to Contract Together

Secretory Fibers in the Enteric Nervous System

Fibers Controlling Absorption

The Plexuses in the Stomach and Colon are Different from Those in the Small Bowel

Pre-and Post-Ganglionic Fibers

Nerves to Mediate the "Myenteric Reflex"

Effects of Certain Drugs on Conduction

Nolf's Model of the Myenteric Plexus

Summary

XII. The Extrinsic Nerves of the Digestive Tract and their Functions

The Peculiar Response of Smooth Muscle to Nervous Stimulation

Effects of Stimulating Vagus Nerves

Chemical Mediators

The Vagi and Splanchnics are Mixed Nerves

Afferent Impulses Injuring the Brain

Mixed Effects of Stimulating Sympathetic Nerves

The Nature of the Involuntary Nervous System

The Functions of the Intestinal Nerves

Vasomotor and Secretory Fibers

Psychic Effects

Effects from the Brain on the Stomach and Bowel

The Innervation of the Stomach

The Effects of Vagonomy in Animal and Man

How Far Down the Bowel do the Vagus Nerves Extend

Celiac Plexuses

The Influence of Nerves in Quieting the Bowel in Case of Peritonitis

Nerves to the Liver

Nerves of the Crop and Gizzard in the Chicken

Summary

XIII. Chewing and Swallowing

The Value of Chewing

The Esophagus

Swallowing

Reverse Peristalsis in the Esophagus

Air Swallowing

Dysphagia

Is the Act of Swallowing Essential to Life

Summary

XIV. The Cardia

Why the Cardia is Weak

Rhythmic Tendencies

Regurgitation

The Nervous Control of the Cardia

Cardiospasm and Hirschsprung's Disease

Summary

XV. The Movements of the Stomach

Way in Which Waves Travel Over the Stomach

Literature on Gastric Movements

Conduction in the Stomach

Changes in Tonus

A Humoral Influence on Gastric Activity

Mode of Travel of Solids and Liquids Through the Stomach

The Gastric Canal or Furrow ("Magenstrasse")

The Blood Vessels of the "Magenstrasse" and Duodenal Cap

The Position of the Stomach in the Abdomen

The Influence of Sleep

The Influence of Food and Drugs

The Stomach of Infants

Summary

XVI. Gradients in the Muscular Wall of the Stomach

The Primitive Digestive Tube and its Modifications

Differences in Rhythmicity in Different Parts of the Stomach

Differences in Tonus

Differences in Irritability and Latent Period

Differences in the Reactions of Excised Strips of Muscle

Summary

XVII. The Pylorus and the Duodenal Cap

A Fibrous Tissue Barrier

A Physiological Barrier

The Duodenal Cap

Influences Crossing the Pyloric Line

Passage of Material Through the Pylorus

The Emptying of the Cap

Autonomy of the Pylorus

The Control of the Pylorus

Re-Gurgitation of Duodenal Contents into the Stomach

Gastric Emptying Due to an Upset in Balance Between Intragastric and Intraduodenal Pressures

Nervous and Other Influences Affecting the Pylorus

Emptying Time of the Stomach as an Index of Digestibility of Foods

Pyloric Stenosis in Infancy

The Duodenum Below the Cap

Summary

XVIII. Hunger Contractions and the Pain of Ulcer

Hunger Contractions

The Pain of Ulcer

Notes on Abdominal Pain in General

Summary

XIX. Movements of the Stomach hat is Diseased or has Been Operated On

Movements of the Stomach that is Diseased

Effects of Removal of Portions of the Stomach

Summary

XX. Vomiting

Trigger Zones from Which Vomiting Can be Started

Regurgitation Due to the Efforts of the Digestive Tract Alone

The Part Played by the Voluntary Muscles

Behavior of the Stomach During Vomiting

Behavior of the Cardia and Esophagus

Behavior of the Bowel

The Vomiting Center

The Pathways for Afferent and Efferent Impulses

Influences Coming from the Heart

Pregnancy

Association Between Vomiting and Diarrhea

Practical Applications

Vomiting Not Always Prevented by Keeping Drugs Out of the Stomach

Summary

XXI. The Mechanics of the Gallbladder

Embryology

Anatomy

Filling of the Gallbladder

Absorption from the Gallbladder

Other Functions of the Gallbladder

Emptying of the Gallbladder

Effect of Cholecystectomy on the Bile Ducts

Mode of Production of Pain in Gallbladder Disease

Summary

XXII. The Muscularis Mucosae

Summary

XXIII. The Ileocecal Sphincter

The Gastro-Ileac Reflex

An Ileo-Gastric Reflex

Receptive Relaxation of the Colon

The Nervous Control of the Sphincter

Regurgitation Through the Sphincter

The Function of the Sphincter

Reason for Blockage of Waves at the Ileocecal Sphincter

Anatomy and Embryology

Summary

XXIV. The Appendix

Summary

XXV. The Movements of the Colon

The Water-Conserving Function of the Colon

The Colons of Herbivora and Carnivora

Movements of the Colon

The Formation of Mucus in the Colon

Nerve Supply of the Colon

Defecation

Summary

XXVI. The Length and Complexity of the Bowel as Influenced by Diet

The Length of the Small Intestine

Is Man Built to be Herbivorous or Carnivorous

Summary

XXVII. The Rate of Progress of Food Residues Through the Digestive Tract

The Rate of Progress in the Small Intestine

The Influence of High and Low Residue Diets

Summary

XXVIII. Constipation

Atony of the Colonic Muscle

A Possible Reversal of the Rectal Gradient

Lack of Vis a Tergo

The Abuse of Purgatives

The Peculiar Sensitiveness of the Rectum to Pressure

Puzzles as to How Bulky Diets Relieve Constipation

Attempts to Work Out a Surgical Treatment for Constipation

Summary

XXIX. Gas in the Bowel

Where does the Gas Come from

How Gas Gets Out of the Bowel

Flatulence and Aviation

Bloating After the Cutting of Nerves

Matters Historical and Amusing

Clinical Applications

Accute Dilatation of the Stomach

Borborygmus

The Action of Carminatives

Postoperative "Gas Pains"

Summary

XXX. Hunger, Appetite and Thirst

The Sensations of Hunger

Appetite

Thirst

Summary

XXXI. The Modus Operandi of a Gastro-Enterostomy

Function of the Stomach after Gastro-Enterostomy

Why does a Gastro-Enterostomy Give Relief in Cases of Ulcer

Summary

XXXII. The Electrogastrogram and Electro-Enterogram

Summary

XXXIII. Technical Methods and Apparatus

Roentgen Rays and the Barium Meal

Method of Auer

Gastric and Duodenal Tubes and Balloons, and Electrodes

Intestinal Fistulas

Opening the Abdomen Under Salt Solution

Excised Whole Small Bowel

Studies of Small Excised Segments of Bowel

Abdominal Windows

Transplanted Segments of Stomach, Pancreas, or Bowel

The Electrogastrogram and the Electro-Enterogram

The Gastroscope

Trans-Parent Fish

Useful Articles on Technic

Summary

XXXIV. On Books and Reading

Bibliography

Index