Gross Anatomy of The Small Intestine Flashcards
What is the length of the small intestine in adults?
Length of small intestine: Approximately 6-7 meters.
Describe the divisions of the small intestine.
Divisions: Duodenum, jejunum, and ileum.
Explain the anatomy of the duodenum.
Anatomy of duodenum: C-shaped, divided into superior, descending, horizontal, and ascending parts.
What are the four parts of the duodenum?
Four parts of duodenum: Superior, descending, horizontal, and ascending.
Describe the location and function of the duodenal papilla.
Duodenal papilla: Opening for common bile duct and pancreatic duct, located in the descending part of the duodenum.
What is the significance of the major duodenal papilla?
Significance of major duodenal papilla: Site of entry for bile and pancreatic secretions into duodenum.
Explain the anatomy of the jejunum.
Anatomy of jejunum: Middle part of small intestine, thicker wall, larger diameter, prominent circular folds.
What are the distinguishing features of the jejunum?
Distinguishing features of jejunum: Thicker wall, larger diameter, prominent circular folds.
Describe the anatomy of the ileum.
Anatomy of ileum: Terminal part of small intestine, thinner wall, smaller diameter, fewer circular folds, Peyer’s patches.
What are the distinguishing features of the ileum?
Distinguishing features of ileum: Thinner wall, smaller diameter, fewer circular folds, Peyer’s patches.
Explain the histological structure of the small intestine wall.
Histological structure of small intestine wall: Mucosa, submucosa, muscularis externa, serosa.
What are the main layers of the small intestine wall?
Main layers of small intestine wall: Mucosa, submucosa, muscularis externa, serosa.
Describe the mucosa layer of the small intestine.
Mucosa layer: Contains epithelium, lamina propria, muscularis mucosae.
What are villi, and what is their function?
Villi: Finger-like projections increasing surface area for absorption.
Explain the role of microvilli in small intestine absorption.
Role of microvilli: Further increase surface area for nutrient absorption.
Describe the structure and function of intestinal glands (crypts of Lieberkühn).
Structure and function of intestinal glands: Contain epithelial cells for secretion and absorption.
What is the function of goblet cells in the small intestine?
Function of goblet cells: Secrete mucus for lubrication and protection of mucosa.
Explain the significance of Paneth cells.
Significance of Paneth cells: Secrete antimicrobial peptides, involved in innate immunity.
Describe the submucosa layer of the small intestine.
Submucosa layer: Contains blood vessels, lymphatics, and submucosal plexus.
What structures are found in the submucosa?
Structures found in submucosa: Blood vessels, lymphatics, submucosal plexus.
Explain the muscularis externa layer of the small intestine.
Muscularis externa layer: Circular and longitudinal muscle layers responsible for peristalsis.
What are the roles of circular and longitudinal muscle layers?
Roles of circular and longitudinal muscle layers: Peristalsis and segmentation.
Describe the serosa layer of the small intestine.
Serosa layer: Outermost layer composed of connective tissue and mesothelium.
What is the significance of the mesentery in small intestine anatomy?
Significance of mesentery: Supports and suspends the small intestine.
Explain the blood supply of the small intestine.
Blood supply of small intestine: Superior mesenteric artery.
What arteries supply the small intestine?
Arteries supplying small intestine: Branches of superior mesenteric artery.
Describe the venous drainage of the small intestine.
Venous drainage of small intestine: Superior mesenteric vein.
What veins drain blood from the small intestine?
Veins draining blood from small intestine: Superior mesenteric vein.
Explain the lymphatic drainage of the small intestine.
Lymphatic drainage of small intestine: Lymphatic vessels and nodes, including Peyer’s patches.
What is the role of lacteals in small intestine lymphatic drainage?
Role of lacteals in lymphatic drainage: Absorb dietary fats and fat-soluble vitamins.
Describe the innervation of the small intestine.
Innervation of small intestine: Enteric nervous system, autonomic nervous system (sympathetic and parasympathetic).
What are the components of the enteric nervous system in the small intestine?
Components of enteric nervous system: Myenteric plexus and submucosal plexus.
Explain the role of the vagus nerve in small intestine innervation.
Role of vagus nerve: Parasympathetic innervation enhancing gastrointestinal function.
Describe the sympathetic innervation of the small intestine.
Sympathetic innervation: From prevertebral ganglia, inhibits gastrointestinal activity.
What is the role of the myenteric plexus in small intestine function?
Role of myenteric plexus: Controls gastrointestinal motility.
Explain the function of the submucosal plexus in the small intestine.
Function of submucosal plexus: Regulates glandular secretions and mucosal blood flow.
Describe the nerve supply to the mucosa of the small intestine.
Nerve supply to mucosa: From submucosal and myenteric plexuses.
What are the clinical correlations related to the small intestine?
Clinical correlations: Bowel obstruction, tumors, surgical complications, nutrient absorption, immune function.
Explain the significance of small intestine anatomy in bowel obstruction.
Significance of small intestine anatomy in bowel obstruction: Can cause abdominal pain, distension, and vomiting.
Describe the presentation of small intestine tumors.
Presentation of small intestine tumors: Abdominal pain, weight loss, change in bowel habits, obstruction.
What are the complications of small intestine surgery?
Complications of small intestine surgery: Infection, bleeding, anastomotic leaks, adhesions.
Explain the role of the small intestine in nutrient absorption.
Role of small intestine in nutrient absorption: Absorbs nutrients, electrolytes, and water.
Describe the role of the small intestine in immune function.
Role of small intestine in immune function: Contains Peyer’s patches, part of gut-associated lymphoid tissue.
What are the common disorders affecting the small intestine?
Common disorders affecting small intestine: Celiac disease, Crohn’s disease, malabsorption syndromes.
Explain the pathophysiology of celiac disease.
Pathophysiology of celiac disease: Autoimmune reaction to gluten damaging intestinal villi.
Describe the clinical presentation of Crohn’s disease.
Clinical presentation of Crohn’s disease: Abdominal pain, diarrhea, weight loss, fatigue.
What are the complications of small intestine inflammation?
Complications of small intestine inflammation: Malabsorption, strictures, fistulas, abscesses.
Explain the treatment options for small intestine disorders.
Treatment options for small intestine disorders: Dietary modifications, medications, surgery.
Describe the surgical interventions for small intestine pathology.
Surgical interventions for small intestine pathology: Resection, anastomosis, bypass procedures.
