27. Layers of the Stomach скачать в хорошем качестве

27. Layers of the Stomach

𝐒𝐮𝐛𝐬𝐜𝐫𝐢𝐛𝐞 𝗙𝐨𝐫 𝗠𝐨𝐫𝐞 𝗜𝐧𝐟𝐨𝐫𝐦𝐚𝐭𝐢𝐨𝐧 𝐨𝐧 𝗛𝐞𝐚𝐥𝐭𝐡 👩‍⚕‍ 𝐚𝐧𝐝 𝗠𝐞𝐝𝐢𝐜𝐢𝐧𝐞💉🩺💊 📌𝗜𝗻𝘀𝘁𝗮𝗴𝗿𝗮𝗺 :   / clinical.learning   Layers of the Stomach The wall of the stomach is composed of four well-organized layers, each designed to support its complex digestive functions including secretion, motility, and protection from self-digestion. Starting from the innermost, the mucosa is highly specialized and consists of three sublayers – the epithelium, lamina propria, and muscularis mucosae. The epithelium is made up of simple columnar cells that continuously secrete a protective mucus layer to prevent the underlying tissue from being damaged by hydrochloric acid and pepsin. Beneath this lies the lamina propria, a connective tissue layer rich in blood vessels, lymphatics, and immune cells, supporting the gastric glands and enabling immune defense. The muscularis mucosae, a thin smooth muscle layer, allows localized movement of the mucosa to enhance glandular secretion. Deep to this is the submucosa, which is composed of dense connective tissue housing larger blood vessels, lymphatics, and the Meissner’s nerve plexus, enabling structural support and neural regulation of glandular secretion. The next layer, the muscularis externa, is unique in the stomach because it has three smooth muscle layers – an inner oblique, middle circular, and outer longitudinal layer, as opposed to the two layers seen elsewhere in the GI tract. This additional oblique layer allows vigorous churning and mixing of food to form chyme. The circular layer thickens at the pyloric end to form the pyloric sphincter, which regulates the passage of food into the duodenum. Between these muscle layers lies the myenteric (Auerbach’s) plexus, responsible for coordinating peristaltic movements. The outermost layer of the stomach is the serosa, a thin layer of visceral peritoneum made up of simple squamous epithelium (mesothelium), which provides a smooth, slippery surface reducing friction with adjacent abdominal organs. This layer also contributes to the formation of the greater and lesser omenta, which suspend the stomach and carry its blood vessels, lymphatics, and nerves. Together, these layers work in synchrony to perform the vital tasks of mechanical digestion, chemical breakdown, nutrient absorption, and immune protection, making the stomach a dynamic organ essential to gastrointestinal physiology. 🔬🍽️🩸💊 #LayersOfStomach #GastricWallAnatomy #StomachHistology #AnatomySimplified #MBBSNotes #NEETPGPrep #USMLEStep1 #MedicalEducation #StomachAnatomy #GastrointestinalSystem #HistologyLecture #DoctorGoals #MedStudentLife #ClinicalAnatomy