Gastrointestinal Tract: Diseases & Functions

Hepatorenal Syndrome — due to decreased renal blood flow; decreased urine output — increased creatinine and BUN Which type of food move from the stomach to the intestines more quickly Carbohydrates, simple sugars, and zero-calorie liquids Are there any disease that affects gastric emptying...

Hepatorenal Syndrome — due to decreased renal blood flow; decreased urine output — increased creatinine and BUN Which type of food move from the stomach to the intestines more quickly Carbohydrates, simple sugars, and zero-calorie liquids Are there any disease that affects gastric emptying ? Gastroparesis, also called gastric stasis, occurs when there is delayed gastric emptying. Delayed gastric emptying means the stomach takes too long to empty its contents Does the time of the day affect emptying ? Stomach emptying is slower in the evening than in the morning, especially for solid foods. For example, one study found that the gastric emptying half-time for an evening meal was 53.6% longer than for a morning meal. Villi Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption — if you don't use them you lose them if damage bacteria's ho to the blood stream gastric bleeding occurs In the submucosa ? Digestive Processes associated with the GI tract Includes ingestion propulsion: food from mouth to anus secretion of mucus enzymes & water digestion absorption elimination of food. Upper Gastrointestinal Tract Includes the stomach for food storage and initial digestion, with the pylorus opening into the small intestine. Middle Gastrointestinal Tract Consists of the duodenum (10 inches long), common bile duct, main pancreatic duct, jejunum, and ileum (23 feet long). Lower Gastrointestinal Tract Includes the cecum — ileocecal valve: block p of fecal material into the SI colon (ascending, transverse, descending, ), rectum Gastrointestinal Wall Structure Comprises mucosa membrane with submucosa layer, circular muscle, and longitudinal muscle layers. Peritoneal Space A potential space with parietal pleura (abdominal wall) and visceral pleura (organs). Motility Involves rhythmic movements of the gastrointestinal. controlled by hormonal and neuro control, with the parasympathetic (autonomc )and sympathetic divisions playing roles ( sphincter) Change in GI tract with aging Changes in the teeth: sensitivity Salivation decreases: medication Taste buds decline in number: low appetite Gastric motility decreases Intestinal motility decreases Absorption & blood flow decrease: affect metabolism las Blood flow in liver decreases - affects drug metabolism Secretion of enzymes from pancreases decreases peristaltic movement - move food along the digestive tract defecation - controlled by internal and external anal sphincters. cortex - controls the external sphincter Secretory Function Involves the daily secretion and reabsorption of 7000 mls in the gut, with 50 to 200 mls lost through stool. Gastrin- stimulates the production gastric acid, vagal stimulation. it also stimulates the secretion of bicarbonate containing solution and acid pH in the duodenum Cholecystokinin - stimulates contraction of the gall bladder, the release of pancreatic enzymes and amino acids digestion and absorption Digestion of Carbohydrates Digestion of Lipids Digestion of Proteins Changes in the Gastrointestinal Tract with Aging Anorexia Defined as a loss of appetite influenced by factors like hunger and stomach contractions. Nausea Preceded by anorexia, involves receptors like serotonin and dopamine in the fourth ventricle. Vomiting Sudden and Forceful expulsion of stomach contents controlled by the medulla, serving as an adaptive mechanism to get rice of noxious substances Gastrointestinal Bleeding Can occur in the upper GI (esophagus, stomach, duodenum) or lower GI (jejunum, ileum, large intestine) regions. Etiology of GI bleed Includes ulcers, esophageal varices, and hemorrhoids as common causes. Manifestations of GI bleeding Include hematemesis (vomited blood), melena (blood in stool), and occult blood (hidden in stool), elevate BUB and decrease H&H Peptic Ulcer Disease A break or ulceration in the protective mucosal lining of the lower esophagus, stomach, or duodenum Disorders of the Esophagus Tracheoesophageal Fistula - connection between the esophagus and the trachea; cancer, birth defects Gastroesophageal Reflux, Hiatal Hernia, and Mallory Weiss Syndrome. Gastroesophageal Reflux Disease (GERD) — Lack of pressure sphincter — Chyme moves back up into esophagus — Causes: Smoking Chocolate ЕТОН Fatty foods Caffeine Certain medications Obesity/ pregnancy Hiatal Hernia - movement of the stomach through the opening for the esophagus into the diaphragm. Present to some degree in 50% of the population. — can go unnoticed, don't come back after surgery Mallory Weiss Syndrome - tear in the lower esophagus due to prolonged vomiting. Esophageal Varices complication of portal vein hypertension usually due to cirrhosis Esophageal Cancer - squamous cell in origin Incidence - low in US but high in Asia Metastasizes easily because of proximity to lymph nodes Contributing Factors And Manifestations of Esophageal Cancer 1) excessive consumption of alcohol cigarette smoking 2) dysphagia - lumen of esophagus is reduced 30 to 50% outcome with this type of cancer usually poor Gastritis — inflammation of the gastric mucosa Causes - bacterial endotoxin, caffeine, alcohol, aspirin, NSAIDS Manifestations - mild - gastric distress severe - vomiting, bleeding Cause of Peptic Ulcer Disease - alcohol, aspirin, bile acids, Helicobacter pylori Mechanisms - decreased mucus production and prostaglandin deficiency Manifestations of Peptic Ulcer Disease - vague abdominal discomfort to life threatening hemorrhage pain usually burning, cramping pain occurs when the stomach is empty between meals pain located in the mid epigastric area perforation of gastric ulcer can lead to contents in the peritoneum decreased hematocrit Irritable Bowel Syndrome ( intestinal disorder) chronic and recurrent intestinal symptoms 15-20% of population most do not seek medical attention Etiology: stress - hyperactivity of the bowel Manifestations of Irritable Bowel Syndrome symptoms - abdominal pain, complaints of gas pain, bloatedness, nausea, anorexia, anxiety, depression signs - changes in frequency and consistency of stool Crohn's Disease - recurrent inflammatory response which affects any portion of the GI tract. Affects both large and small intestines — peak occurrence is from 15 to 35 years of age