Description
There has long been disagreement about various aspects of the structure and function of the “gatekeeper” (Greek pyloros, from pyle = gate and ouros = guard). In recent years the problem has often been mentioned in anatomy, physiology, gastroenterology, radiology and even in nuclear medicine. For instance, while referring to manometric and gastric emptying studies, Schu urkes and van Nuenten (1984 ) pointed out that there was considerable contro versy as to whether a true pyloric sphincter existed in most species, and espe cially in man. According to Reeve (1981) many functional aspects of sphincters are poorly understood; the exact mechanism of control of the transfer of chyme from stomach to duodenum through the pylorus is still not clear. Malagelada (1983) states that controversy surrounds the motor activity and function of the antro duodenal junction; there is disagreement as to whether the pylorus functions as or as an integral part of the distal antrum. Ehrlein et al. (1984) a separate unit reiterate that pyloric motility is poorly understood, and according to Funch Jensen (1987) there are many unsolved questions. Malagelada (1990) states that the stomach performs multiple functions with a deceivingly simple anat omy; this is regarded as the key to the investigator’s frustration when trying to uncover its secrets. One source of the many controversies surrounding the pylorus may be species differences, according to Schulze-Delrieu et al. (1984). 1 Introduction.- 2 Some Uncertain Concepts.- The Pyloric Antrum.- Discussion.- References.- What is a Sphincter?.- Discussion.- References.- Peristalsis.- Discussion.- References.- 3 The Walls of the Stomach and Duodenum.- Serous Coat:.- Muscular Coat or Muscularis Externa.- Morbid Anatomical Study.- Development of Musculature.- Discussion.- Sphincteric Mechanism at Pylorus.- Terminology.- References.- 4 The Submucous Coat.- Stomach.- Duodenum.- Discussion.- References.- 5 The Mucous Membrane or Mucosa.- Stomach.- Muscularis Mucosae.- Lamina Propria.- Epithelial Lining.- Three Mucosal Zones.- Anatomical Extent and Boundaries of the Pyloric Mucosal Zone.- Duodenum.- Muscularis Mucosae.- Lamina Propria.- Epithelial Lining.- Additional Features of the Mucosa.- Discussion.- References.- 6 Electrical Potential Difference at the Gastroduodenal Mucosal Junction.- Discussion.- References.- 7 Arteries, Veins, Lymphatics.- Arterial Supply.- Venous Drainage.- Lymphatic Drainage.- Discussion.- References.- 8 Nerves.- Parasympathetic Nerve Supply.- Anterior Vagus.- Posterior Vagus.- Parasympathetic Ganglia.- Discussion.- Sympathetic Nerve Supply.- Sympathetic Ganglia..- Discussion.- Peptidergic System.- References.- 9 Regulatory Peptides.- Gastrin.- Somatostatin.- Vasoactive Intestinal Peptide.- Substance P.- Enkephalin.- Galanin.- Neurotensin.- Discussion.- References.- 10 Ultrasonography of Normal Anatomy.- Conventional Surface Ultrasonography of the Normal Infantile Pylorus.- Discussion.- References.- Endoscopic Ultrasonography of the Layer Structure of the Gastric Walls.- Discussion.- References.- 11 Anatomy of the Pyloric Ring.- Radiographic Anatomy.- Present Investigations.- Microscopic Anatomy.- Present Investigations.- Sonographic Anatomy.- Present Investigations.- Discussion.- References.- 12 The Pylorus at Rest: Open or Closed?.- Present Investigations.- Patients and Methods.- Results.- Discussion.- References.- 13 Radiographic Examination of Normal Motility.- Validation Studies.- Intraluminal Pressure Profiles.- Patients, Materials and Methods.- Results in Stomach.- Conclusion.- Results in Duodenum.- Conclusion.- Living Anatomical Studies.- Patients, Materials and Methods.- Results.- Conclusion.- Motor Divisions of Stomach.- Fornix.- Corpus and Sinus.- Distal 3-4 cm.- Do Gastric Peristaltic Waves Progress as Far as the Pyloric Aperture?.- Discussion.- Contraction Patterns of Distal 3-4 cm of Stomach.- Radiological Studies.- Patients and Methods.- Results.- Mucosal Movements.- References.- 14 The Pylorus at Gastroscopy.- Discussion.- References.- 15 Manometry at the Gastroduodenal Junction.- Discussion.- References.- 16 Myoelectric Activity at the Gastroduodenal Junction.- Discussion.- References.- 17 Ultrasonography of Pyloric Motility and Gastric Emptying.- Discussion.- References.- 18 Radionuclides in the Investigation of Gastric Emptying.- Emptying of Liquids and Solids.- Discussion.- References.- 19 Gastric Tone and the Pyloric Sphincteric Cylinder.- Determination of Tone.- Discussion.- Hypotonicity.- Hypertonicity.- References.- 20 Pylorospasm.- Pylorospasm.- Radiological Features.- Problems of Definition.- Patients and Methods.- Discussion.- Pathogenesis.- Ultrasonic Features.- Operative and Experimental Features.- Discussion.- References.- 21 Congenital Anomalies.- Pyloric Atresia.- Discussion.- References.- Duplications.- Discussion.- References.- Congenital Double Pylorus.- Discussion.- References.- Pyloric Membrane, Web or Diaphragm.- Discussion.- References.- Ectopic Pancreatic Tissue.- Discussion.- References.- 22 Partial or Intramural Gastric Diverticulum.- Discussion.- References.- 23 Infantile Hypertrophic Pyloric Stenosis.- Anatomical Localization and Radiographic Features.- Anatomical Localization and Ultrasonic Features.- Pathogenesis and Etiology.- Discussion.- Pathogenesis.- Etiology.- Conclusion.- References.- 24 Adult Hypertrophic Pyloric Stenosis.- Discussion.- Types of AHPS.- Associated Lesions.- Relationship to Infantile Hypertrophic.- Pyloric Stenosis.- Anatomical Localization and Operative Features.- Radiographic Features.- The Pathogenesis and Etiology.- References.- 25 Focal Hypertrophy and Focal Spasm of the Pyloric Musculature in Adults.- Discussion.- References.- 26 Nausea, Retching and Vomiting.- Nausea.- Retching.- Vomiting.- Discussion.- References.- 27 Duodenogastric Reflux.- Previous Tests.- A Double-Contrast Radiographic Test for Duodenogastric Reflux.- Advantages.- Disadvantages.- Results in Normal Subjects.- Results in Patients.- Subsequent Tests.- Discussion.- References.- 28 Gastritis and Erosions in the Pyloric Sphincteric Cylinder.- Present Investigations.- Patients and Methods.- Discussion.- References.- 29 Gastric Ulceration and the Pyloric Sphincteric Cylinder.- Gastric Ulceration Proximal to the Pyloric Sphincteric Cylinder.- Discussion.- Gastric Ulceration within the Pyloric Sphincteric Cylinder.- Discussion.- References.- 30 Duodenal Ulceration and the Pyloric Sphincteric Cylinder.- Present Investigations.- Patients and methods.- Discussion.- References.- 31 Pyloroduodenal Fistula or Acquired Double Pylorus.- Discussion.- References.- 32 Hiatus Hernia and the Pyloric Sphincteric Cylinder.- Infants.- Adults.- Radiographic Studies.- Patients and Methods.- Experimental Studies.- Material and Methods.- Results.- Discussion.- References.- 33 Pyloric Carcinoma.- Present Investigations.- Patients and Methods..- Results.- Pyloric region.- Results.- Duodenum.- Discussion.- Emptying of Solids and Liquids.- Duodenal Spread.- Brunner’s glands and EGF.- References.- 34 Malignant Lymphoma.- Discussion.- References.- 35 Malignancy at the Gastro-oesophageal Junction.- Discussion.- References.- 36 Sessile Polyps in the Sphincteric Cylinder.- Peutz-Jeghers Syndrome.- Discussion.- References.- 37 Diabetes Mellitus.- Discussion.- References.- 38 Prolapse of Gastric Mucosa into the Duodenum.- Normal Mobility of the Mucosa.- Pathoanatomical Diagnosis.- Surgical Diagnosis.- Gastroscopic Diagnosis.- Radiological Diagnosis.- Discussion.- Types and Grades of Prolapse.- Relationship to Cyclical Activity of Sphincteric Cylinder.- The Radiological Differential Diagnosis.- Associated Gastroduodenal Lesions.- Possible True Complications.- Malignancy and Prolapse of Gastric Mucosa.- References.- 39 Acid Corrosive Injuries and the Pyloric Sphincteric Cylinder.- Discussion.- References.
