Survival of Vibrio Choleræ in Gastric Juice

The gastric phase of digestion begins as soon as food enters the stomach. The incoming food bolus triggers neural and hormonal mechanisms, which last approximately 3 to 4 hours. During this phase, the stomach undergoes significant changes to prepare the food for further digestion and absorption.
When food enters the stomach, it stretches the stomach walls and activates stretch receptors. This triggers local reflexes of the enteric nervous system, mediated through the myenteric plexus. These...

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

The gastric glands contain parietal cells that secrete hydrochloric acid (HCl) for digestion. The cells secrete HCl because it is highly corrosive and essential for breaking down food. To achieve this, they secrete hydrogen and chloride ions into the lumen of the gastric glands, which combine to form HCl.
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...

In cases of acute poisoning, the primary objective is to prevent further absorption of the toxic substance into the body. Immediate interventions using various decontamination techniques targeting the gastrointestinal (GI) tract can achieve this. Decontamination is crucial to prevent poison from entering the systemic circulation, which involves washing affected areas with water and mild soap and removing contaminated clothing. Once external decontamination is done, attention must be turned to...

The small intestine plays a crucial role in our digestive system, performing both mechanical and chemical digestion.
Mechanical digestion in the small intestine involves movements such as segmentations and migrating motility complexes (MMCs), primarily controlled by the myenteric plexus. Segmentations are localized contractions occurring in areas of the intestine distended by chyme—a mixture of partially digested food. These contractions mix chyme with digestive juices, facilitating...

The human body contains a monogastric digestive system. In a monogastric digestive system, the stomach only contains one chamber in which it digests food. Several other animal species also have monogastric digestive systems, including pigs, horses, dogs, and birds. This chapter, however, focuses on the human digestive system.