The Digestive System PDF

1. Anorexia ​ Definition: Lack of desire to eat despite the physiological need for food. ​ Associated with: ○​ Emotional factors (e.g., stress, depression). ○​ Abdominal pain or indigestion. ○​ D...

1. Anorexia ​ Definition: Lack of desire to eat despite the physiological need for food. ​ Associated with: ○​ Emotional factors (e.g., stress, depression). ○​ Abdominal pain or indigestion. ○​ Diarrhea or nausea. ​ Mechanism: Often accompanies other disorders or conditions that affect appetite (e.g., chronic illnesses or medications). ​ Role of Smell: Smell significantly influences appetite; unpleasant smells can exacerbate anorexia. 2. Vomiting ​ Definition: Forceful expulsion of stomach and intestinal contents (vomitus). ​ Mechanism: 1.​ Reverse Peristalsis: Starts in the stomach or duodenum. 2.​ Medulla (vomiting center in the brain) activates abdominal muscles to contract, opening the sphincters and expelling contents. ​ Triggers: 1.​ Drugs, trauma (e.g., to ovaries, testes, or brain), infections, or toxins. 2.​ Sensitization of mucosal lining, stretching of the stomach, or irritation. ​ Stages: 1.​ Nausea: Unpleasant sensation often accompanied by sweating, pallor, and fast heartbeat. 2.​ Retching: Dry heaving without expulsion. 3.​ Vomiting: Expulsion of contents. ​ Complications: Dehydration, electrolyte imbalance, aspiration pneumonia if contents enter the airway. 3. Constipation ​ Definition: Difficult or infrequent bowel movements. ​ Causes: ○​ Personal habits (ignoring the urge to defecate). ○​ Inactivity or lack of exercise. ○​ Inadequate fluid intake or a low-fiber diet. ○​ Medications (e.g., opioids, antacids). ○​ Medical conditions: Spinal cord injuries, Parkinson’s disease, hypothyroidism, multiple sclerosis. ​ Mechanism: ○​ Material stays in the large intestine too long, leading to excess water reabsorption. This makes the stool dry, hard, and difficult to pass. ​ Symptoms: Straining, hard stools, feeling of incomplete evacuation. 4. Fecal Impaction ​ Definition: Hard stool forms in the distal colon or rectum, obstructing the passage of feces. ​ Causes: ○​ Chronic constipation, low-fiber diet, neurological diseases (e.g., stroke), or immobility. ​ Symptoms: ○​ Severe constipation (no bowel movements for days or weeks). ○​ Abdominal distention and bloating. ○​ Watery diarrhea may occur if liquid stool leaks around the impaction. ○​ Blood in stool due to irritation or pressure on the rectum. ​ Complications: Complete obstruction, risk of bowel perforation, and secondary infections. 5. Diarrhea ​ Definition: Increase in stool frequency, fluidity, or volume. ​ Types: ○​ Osmotic Diarrhea: Non-absorbable substances draw water into the intestine (e.g., lactose intolerance). ○​ Secretory Diarrhea: Excessive secretion of fluids by the intestinal lining (e.g., infections like cholera). ○​ Inflammatory Diarrhea: Inflammation increases motility and reduces absorption (e.g., Crohn's disease, ulcerative colitis). ​ Complications: ○​ Prolonged diarrhea can cause dehydration, electrolyte imbalance, and weight loss. ○​ High risk in children and the elderly due to their lower fluid reserves. 6. Abdominal Pain ​ Types: ○​ Visceral Pain: ​ Originates from internal organs. ​ Diffuse, dull, and poorly localized (e.g., stretching of organs or inflammation). ○​ Parietal Pain: ​ From the peritoneal lining. ​ Sharp, intense, and well-localized (e.g., peritonitis). ○​ Referred Pain: ​ Pain felt in a different area due to shared nerve pathways (e.g., gallbladder pain felt in the shoulder). ​ Causes: ○​ Mechanical (e.g., organ stretching). ○​ Inflammatory (e.g., appendicitis). ○​ Ischemic (e.g., reduced blood supply to intestines). 7. GI Bleeding ​ Definition: Bleeding from any part of the gastrointestinal tract. ​ Types: ○​ Hematemesis: Vomiting blood; fresh (bright red) or digested (coffee-ground appearance). ○​ Melena: Black, tarry stool due to digested blood (from the stomach or small intestine). ○​ Hematochezia: Bright red blood in stool, usually from the rectum or lower colon. ○​ Occult Bleeding: Microscopic blood in stool, detectable via lab tests. ​ Causes: ○​ Upper GI Bleeding: Peptic ulcers, esophageal varices, or Mallory-Weiss tears. ○​ Lower GI Bleeding: Diverticulitis, colorectal cancer, or hemorrhoids. ​ Complications: ○​ Acute, severe bleeding can cause hypovolemic shock (low blood volume), rapid heart rate, and low blood pressure. ○​ Chronic bleeding may lead to anemia. Deglutition (Swallowing) ​ Definition: The process of moving food and liquids from the mouth to the stomach through coordinated muscle actions. ​ Phases: 1.​ Oral Phase (Voluntary): ​ Food is chewed and mixed with saliva to form a bolus. ​ The tongue pushes the bolus to the back of the throat (pharynx). 2.​ Pharyngeal Phase (Involuntary): ​ Soft palate and uvula close off the nasal passages to prevent food from entering the nose. ​ The epiglottis covers the airway to stop food from entering the lungs. 3.​ Esophageal Phase (Involuntary): ​ The bolus moves down the esophagus via peristalsis (wave-like muscle contractions). ​ The lower esophageal sphincter (LES) opens, allowing food to enter the stomach. Disorders of the Esophagus 1.​ Dysphagia ○​ Definition: Difficulty swallowing. ○​ Causes: ​ Lack of saliva (e.g., dehydration, Sjögren's syndrome). ​ Obstructions (e.g., tumors, strictures). ​ Impaired esophageal motility (e.g., stroke affecting cranial nerves V, IX, X, XII). ○​ Symptoms: ​ Feeling of food sticking in the throat or chest. ​ Risk of choking or aspiration. 2.​ Achalasia ○​ Definition: Loss of nerve function in the lower esophageal sphincter (LES), preventing relaxation and causing food to remain in the esophagus. ○​ Mechanism: ​ Peristalsis in the esophagus is severely impaired. ​ LES fails to open properly, leading to difficulty passing food to the stomach. ○​ Symptoms: ​ Chest pain after swallowing. ​ Regurgitation of undigested food. ​ Weight loss. 3.​ Hiatal Hernia ○​ Definition: Protrusion of the upper stomach into the thoracic cavity through the diaphragm (esophageal hiatus). ○​ Types: ​ Sliding Hiatal Hernia: Stomach and LES slide into the thoracic cavity. ​ Paraesophageal Hernia: Part of the stomach pushes through but the LES remains in place. ○​ Symptoms: Often asymptomatic, but may include: ​ GERD (gastroesophageal reflux disease). ​ Heartburn or regurgitation. ​ Chest pain, especially after eating. ○​ Complications: Strictures, esophagitis, or increased risk of cancer. 4.​ Gastroesophageal Reflux Disease (GERD) ○​ Definition: Chronic reflux of stomach contents into the esophagus due to a weak LES. ○​ Mechanism: ​ Stomach acid damages the esophageal mucosa, leading to inflammation (esophagitis). ○​ Triggers: ​ Lying down after eating, obesity, spicy foods, caffeine, alcohol. ○​ Symptoms: ​ Persistent heartburn (burning sensation in the chest). ​ Regurgitation of acidic contents. ​ Chronic cough or sore throat. ○​ Complications: ​ Barrett's esophagus: Precancerous changes in esophageal lining. ​ Esophageal stricture: Scar tissue narrows the esophagus. 5.​ Esophageal Varices ○​ Definition: Dilated veins in the esophagus, usually due to increased pressure in the portal vein (portal hypertension). ○​ Causes: ​ Liver cirrhosis or severe liver disease. ○​ Symptoms: ​ Often asymptomatic until rupture. ​ Massive bleeding (vomiting blood, black stools). ​ Risk of life-threatening hemorrhage. ○​ Complications: High mortality rate due to severe blood loss. 6.​ Esophageal Cancer ○​ Definition: Malignant tumor of the esophagus, typically adenocarcinoma or squamous cell carcinoma. ○​ Risk Factors: ​ Chronic GERD, smoking, alcohol, Barrett’s esophagus, obesity. ○​ Symptoms: ​ Progressive dysphagia (starts with solids, then liquids). ​ Weight loss, chest pain, or hoarseness. ○​ Prognosis: Early diagnosis improves survival, but advanced cases have a poor prognosis. The Stomach ​ Function: ○​ Temporary storage for food (~2–4 liters capacity). ○​ Chemical digestion: Uses enzymes (e.g., pepsin) and acids (e.g., hydrochloric acid) to break down proteins. ○​ Mechanical digestion: Muscles churn and mix food with gastric juices to form chyme (a semi-liquid substance). ○​ Protection: Produces mucus to protect its lining from its own acids and enzymes. Disorders of the Stomach 1. Gastritis ​ Definition: Inflammation of the gastric mucosa (stomach lining). ​ Types: ○​ Acute Gastritis: Sudden onset, often self-limiting. ○​ Chronic Gastritis: Long-term inflammation that can lead to atrophy of the stomach lining. ​ Causes: ○​ Alcohol, smoking, spicy foods. ○​ Medications (e.g., NSAIDs like ibuprofen inhibit prostaglandins that protect the stomach). ○​ Infections (e.g., Helicobacter pylori bacteria). ○​ Autoimmune diseases (e.g., attacking the stomach lining). ​ Symptoms: ○​ Nausea, vomiting, loss of appetite. ○​ Abdominal discomfort, bloating. ○​ Bleeding (vomiting blood or black, tarry stools). ​ Complications: ○​ Chronic gastritis increases the risk of ulcers and gastric cancer. 2. Peptic Ulcer Disease (PUD) ​ Definition: A break or ulceration in the mucosal lining of the stomach, duodenum, or lower esophagus. ​ Types: ○​ Gastric Ulcers: In the stomach. ○​ Duodenal Ulcers: More common and occur in the first part of the small intestine. ○​ Stress Ulcers: Develop during severe illness, trauma, or major surgery. ​ Causes: ○​ H. pylori infection: Damages the protective mucosa, allowing acid to erode the stomach lining. ○​ Chronic NSAID use: Reduces mucus protection. ○​ Smoking, excessive alcohol, stress, and spicy foods exacerbate the condition. ​ Symptoms: ○​ Burning or gnawing pain in the epigastric region. ​ Pain is often worse with an empty stomach and may improve with food or antacids. ○​ Nausea, vomiting, bloating. ○​ Weight loss and loss of appetite. ​ Complications: ○​ Bleeding: Vomiting blood (hematemesis) or black stools (melena). ○​ Perforation: Ulcer erodes through the stomach wall, causing peritonitis (life-threatening). ​ Peritonitis is the inflammation of the peritoneum caused by bacterial invasion and chemical irritation ​ Fluids (exudates) leak into the peritoneal cavity → dehydration and inflammation. ​ Symptoms: abdominal pain, shallow breathing, vomiting and fever ​ Can cause a shock (low bp) if left untreated ○​ Obstruction: Scar tissue blocks food passage. 3. Helicobacter pylori Infection ​ Definition: A bacterial infection that disrupts the stomach’s protective lining. ​ Transmission: Contaminated food, water, or saliva. ​ Effects: ○​ Damages mucosa, increasing risk for gastritis, ulcers, and gastric cancer. ○​ Can survive stomach acid by neutralizing it with urease production. 4. Stress Ulcers ​ Definition: Acute ulcers that occur during physical stress (e.g., severe burns, trauma, or major surgeries). ​ Causes: Reduced blood flow to the stomach leads to ischemia and mucosal damage. ​ Symptoms: Often asymptomatic until complications like bleeding occur. 5. Gastric Cancer ​ Definition: Malignant tumors in the stomach, often associated with chronic gastritis or H. pylori infection. ​ Risk Factors: ○​ Chronic H. pylori infection. ○​ Diet high in smoked, salted, or pickled foods. ○​ Smoking, obesity, family history. ​ Symptoms: ○​ Weight loss, persistent epigastric pain. ○​ Nausea, vomiting, early satiety (feeling full quickly). ○​ Signs of bleeding (vomiting blood or black stools). Comparison Between Gastric and Duodenal Ulcers Feature Gastric Ulcer Duodenal Ulcer Location Stomach lining Duodenum Pain timing Worsens with eating Relieved by eating, occurs later (e.g. at night) Risk Factors H. Pylori, NSAIDs, smoking, alcohol H. Pylori, NSAIDs, smoking, alcohol, stress, genetics Complications Higher risk of cancer Most likely to puncture Small Intestine ​ Function: 1.​ Primary site for digestion and absorption of nutrients.  2.​ Receives enzymes from the pancreas and bile from the liver to break down carbohydrates, proteins, and fats. 3.​ Absorbs nutrients via villi and microvilli, increasing surface area. ​ Sections: 1.​ Duodenum: First part, responsible for chemical digestion. 2.​ Jejunum: Middle section, absorbs nutrients. 3.​ Ileum: Final section, absorbs bile salts and vitamin B12. Large Intestine (Colon) ​ Function: ○​ Absorbs water and electrolytes. ○​ Forms and stores feces for excretion. ○​ Hosts gut bacteria that aid in fermentation and vitamin production (e.g., vitamin K). ​ Sections: ○​ Cecum (with the appendix), ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anus. Disorders of the Small and Large Intestines 1. Irritable Bowel Syndrome (IBS) ​ Definition: A functional gastrointestinal disorder characterized by chronic abdominal discomfort and altered bowel habits. ​ Cause: ○​ No structural abnormalities; possible triggers include stress, diet, and gut-brain axis dysfunction. ​ Symptoms: ○​ Alternating diarrhea and constipation. ○​ Abdominal pain relieved by defecation. ○​ Bloating, urgency, and gas. ​ Treatment: ○​ Dietary changes (e.g., low-FODMAP diet), fiber supplements, stress management, and medications (e.g., antispasmodics). 2. Inflammatory Bowel Disease (IBD) ​ Definition: Chronic inflammatory conditions, including Crohn’s disease and ulcerative colitis. Crohn’s Disease ​ Affected Area: Can involve any part of the GI tract, commonly the terminal ileum and colon. ​ Type of Inflammation: Transmural (affects all layers of the intestinal wall). ​ Symptoms: ○​ Persistent diarrhea, abdominal pain (often in the RLQ). ○​ Weight loss, fatigue, and malabsorption (e.g., vitamin B12 deficiency). ​ Complications: ○​ Fistulas (abnormal connections between organs). ○​ Strictures leading to obstruction. ○​ Perforation and abscess formation. ​ Key Feature: Skip lesions (patchy inflammation with normal areas in between). Ulcerative Colitis ​ Affected Area: Confined to the colon and rectum, starting at the rectum and progressing upward. ​ Type of Inflammation: Limited to the mucosa and submucosa. ​ Symptoms: ○​ Frequent, bloody diarrhea with mucus. ○​ Crampy abdominal pain and urgency. ○​ Systemic symptoms (e.g., fever, fatigue). ​ Complications: ○​ Toxic megacolon (severe dilation of the colon). ○​ Increased risk of colon cancer. ​ Key Feature: Continuous inflammation with no skip lesions. 3. Diverticular Disease ​ Diverticulosis: Presence of small pouches (diverticula) in the colon wall. ○​ Common in older adults and often asymptomatic. ​ Diverticulitis: Inflammation of diverticula, usually due to trapped fecal matter. ○​ Symptoms: LLQ abdominal pain, fever, nausea, and changes in bowel habits. ○​ Complications: Abscess, perforation, fistulas, and peritonitis. ​ Treatment: ○​ High-fiber diet for diverticulosis. ○​ Antibiotics and bowel rest for diverticulitis; surgery for severe cases. 4. Appendicitis ​ Definition: Inflammation of the appendix, usually caused by obstruction (e.g., fecalith or foreign body). ​ Symptoms: ○​ Periumbilical pain that localizes to the RLQ (McBurney’s point). ○​ Fever, nausea, vomiting, and anorexia. ​ Complications: ○​ Perforation leading to peritonitis. ​ Treatment: Appendectomy (surgical removal of the appendix). 5. Infectious Enterocolitis ​ Definition: Infections of the intestines caused by viruses, bacteria, or parasites. ​ Causes: ○​ Viral: Rotavirus, Norovirus (common in outbreaks). ○​ Bacterial: Salmonella, Clostridium difficile (C. diff), E. coli. ○​ Parasitic: Giardia. ​ Symptoms: ○​ Acute onset of diarrhea (watery or bloody). ○​ Abdominal cramps, fever, nausea, and dehydration. ​ Complications: Severe dehydration, sepsis (in bacterial infections). ​ Treatment: Rehydration (oral or IV fluids), antibiotics for bacterial infections, and probiotics. 6. Intestinal Obstruction ​ Definition: Blockage in the intestine that prevents normal movement of contents. ​ Types: ○​ Mechanical: Physical blockage (e.g., hernia, tumor, adhesions, volvulus, intussusception). ○​ Functional: Impaired motility (e.g., paralytic ileus). ​ Symptoms: ○​ Severe abdominal pain, distention. ○​ Nausea, vomiting, constipation, and absence of bowel sounds. ​ Complications: ○​ Ischemia, perforation, and sepsis if untreated. ​ Treatment: ○​ Nasogastric tube decompression. ○​ Surgery for mechanical obstructions. 7. Celiac Disease ​ Definition: Autoimmune reaction to gluten (a protein in wheat, rye, barley) that damages the small intestine’s mucosa. ​ Symptoms: ○​ Chronic diarrhea, bloating, and weight loss. ○​ Malabsorption: Deficiencies in iron, calcium, and vitamins (e.g., B12, D). ​ Diagnosis: Blood tests (anti-tissue transglutaminase antibodies) and biopsy. ​ Treatment: Lifelong gluten-free diet. 8. Colorectal Cancer ​ Definition: Cancer of the colon or rectum. ​ Risk Factors: ○​ Family history, IBD, high-fat/low-fiber diet, smoking, obesity. ​ Symptoms: ○​ Rectal bleeding, changes in bowel habits, weight loss, and anemia. ​ Prevention: Regular screenings (e.g., colonoscopy). Obesity  ​ Definition: Excess body fat that poses health risks and causes multiple organ-specific complications. ​ Criteria: ○​ Body Mass Index (BMI): ​ BMI ≥ 30 = Obese ​ BMI 25–29.9 = Overweight ○​ Waist-to-Hip Ratio (WHR): ​ 1.0 in males and >0.8 in females indicates higher risk of morbidity and mortality. ○​ Abdominal Girth: Measurement of the abdomen to assess fat distribution. ​ Types of Obesity: ○​ Upper Body (Central/Abdominal): Fat around the abdomen; linked to higher health risks. ○​ Lower Body (Peripheral): Fat around hips and thighs; less risky than central obesity. ​ Causes: ○​ Exogenous: Excess calorie intake. ○​ Endogenous: Metabolic disorders (e.g., thyroid dysfunction). ○​ Other Factors: ​ Genetics. ​ Psychological and behavioral issues. ​ Increased fat cell size/number. ​ Secondary to endocrine conditions like hypothyroidism. ​ Clinical Manifestations: ○​ Hypertension (45%). ○​ Type II Diabetes (39%). ○​ Coronary Artery Disease (23%). ○​ Pulmonary disorders and joint problems (e.g., arthritis). ○​ Increased risk of certain cancers. Eating Disorders 1. Anorexia Nervosa ​ Definition: A psychological disorder leading to self-imposed starvation and malnutrition, resulting in extremely low body weight (15% below normal). ​ Characteristics: ○​ Intense fear of weight gain. ○​ Misperception of body size and shape. ○​ Restriction of energy intake. ​ Common in: Females (10:1 female-to-male ratio). ​ Clinical Manifestations: ○​ Amenorrhea (loss of menstruation) and loss of secondary sexual characteristics. ○​ Atrophy of breast, bone, muscle, and brain tissue. ○​ Bradycardia (slow heart rate), hypotension (low blood pressure), hypothermia (low body temperature). ○​ Constipation, sleep disturbances, anxiety, and depression. ○​ Risk of death if body weight drops >35% due to cardiac failure. ​ Diagnosis: ○​ Based on physical and psychological exams, ruling out other causes of malnutrition. ​ Treatment: Multidisciplinary approach focusing on nutrition, therapy, and medical care. 2. Bulimia Nervosa ​ Definition: Recurrent binge eating episodes (loss of control) followed by compensatory behaviors to prevent weight gain. ​ Characteristics: ○​ Binge/purge cycles occur at least 1x/week for 3 months. ○​ Misperception of body size and shape. ○​ May coexist with anorexia nervosa (50% overlap). ​ Compensatory Behaviors: ○​ Self-induced vomiting, misuse of laxatives, excessive exercise, or fasting. ​ Common in: Females (10:1 female-to-male ratio). ​ Clinical Manifestations: ○​ Physical: ​ Normal body weight (often within normal BMI range). ​ Teeth enamel loss (from stomach acid). ​ Pharyngeal and esophageal inflammation. ​ Rectal bleeding (from laxative overuse). ○​ Systemic: ​ Fluid and electrolyte imbalances. ​ Depression, anxiety, and guilt after binge episodes. ​ Complications: ○​ Severe electrolyte imbalance may lead to muscle weakness, seizures, or arrhythmias. ​ Treatment: ○​ Cognitive-behavioral therapy (CBT). ○​ Rarely requires hospitalization unless complications are severe. The Liver Major Functions: 1.​ Production of Bile: ○​ Bile emulsifies fats, breaking large fat globules into smaller droplets to aid digestion. 2.​ Detoxification: ○​ Filters toxins, drugs, and harmful substances. ○​ Converts ammonia to urea for excretion. 3.​ Metabolism: ○​ Carbohydrate storage (glycogen) and glucose regulation. ○​ Lipid metabolism (cholesterol synthesis, triglyceride storage). ○​ Protein metabolism (conversion of amino acids, clotting factors production). 4.​ Storage: ○​ Vitamins (A, D, E, K, B12) and minerals (iron, copper). 5.​ Blood Regulation: ○​ Produces plasma proteins (albumin) and clotting factors. Liver Disorders 1. Viral Hepatitis ​ Definition: Inflammation of the liver caused by viruses (HAV, HBV, HCV, HDV, HEV). ​ Transmission: ○​ HAV: Fecal-oral route (contaminated food or water). ○​ HBV & HCV: Bloodborne, sexual transmission, or drug use. ○​ HDV: Requires HBV for infection. ○​ HEV: Fecal-oral, often in developing countries. ​ Phases of Hepatitis: ○​ Prodromal Phase: ​ Begins ~2 weeks after exposure, with vague symptoms (fatigue, nausea, low-grade fever, abdominal pain). ○​ Icteric Phase: ​ Jaundice, dark urine, clay-colored stools, liver enlargement. ○​ Recovery Phase: ​ Symptoms gradually resolve; liver function normalizes within weeks to months. ​ Complications: ○​ Chronic hepatitis (especially HBV and HCV). ○​ Cirrhosis or liver cancer. 2. Cirrhosis ​ Definition: Chronic, irreversible liver damage characterized by scarring and loss of function. ​ Causes: ○​ Chronic alcoholism (most common cause). ○​ Viral hepatitis (HBV, HCV). ○​ Autoimmune diseases. ○​ Metabolic disorders (e.g., Wilson's disease, hemochromatosis). ​ Pathophysiology: ○​ Inflammation and fibrosis disrupt normal liver structure. ○​ Nodular regeneration compresses blood vessels and bile ducts, impairing function. ​ Clinical Manifestations: ○​ Early Signs: Fatigue, anorexia, weight loss, weakness. ○​ Advanced Signs: ​ Jaundice (yellowing of skin and eyes due to bilirubin buildup). ​ Ascites (fluid accumulation in the abdominal cavity). ​ Portal hypertension (high pressure in the portal vein leading to complications like esophageal varices). ​ Hepatic encephalopathy (confusion, tremors, coma due to toxin buildup, especially ammonia). 3. Non-Alcoholic Fatty Liver Disease (NAFLD) ​ Definition: Accumulation of fat in liver cells not related to alcohol. ​ Risk Factors: ○​ Obesity, diabetes, high cholesterol, sedentary lifestyle. ​ Symptoms: ○​ Often asymptomatic but may cause fatigue and right upper quadrant discomfort. ​ Complications: ○​ Can progress to non-alcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. 4. Alcoholic Liver Disease ​ Definition: Liver damage caused by excessive alcohol consumption. ​ Stages: 1.​ Fatty Liver (Steatosis): ​ Reversible with alcohol cessation. ​ Accumulation of fat in liver cells. 2.​ Alcoholic Hepatitis: ​ Inflammation and necrosis of liver cells. ​ Symptoms: Fever, jaundice, abdominal pain. 3.​ Alcoholic Cirrhosis: ​ Irreversible fibrosis and scarring. ​ High risk of liver failure and cancer. 5. Portal Hypertension ​ Definition: Increased blood pressure in the portal venous system. ​ Causes: Cirrhosis, thrombosis, or fibrosis in the liver. ​ Complications: ○​ Esophageal Varices: Dilated veins in the esophagus that can rupture and cause life-threatening bleeding. ○​ Splenomegaly: Enlargement of the spleen. ○​ Ascites: Fluid buildup in the abdomen. ○​ Caput Medusae: Dilated abdominal veins visible on the skin. 6. Hepatic Encephalopathy ​ Definition: Neurological impairment caused by the accumulation of toxins (e.g., ammonia) in the blood due to liver dysfunction. ​ Symptoms: ○​ Early: Tremors, personality changes, lethargy, sleep disturbances. ○​ Late: Confusion, stupor, convulsions, and coma.  ​ Treatment: ○​ Lactulose (to reduce ammonia levels). ○​ Protein restriction in severe cases. 7. Liver Cancer ​ Definition: Malignant tumors originating in the liver, often due to chronic hepatitis or cirrhosis. ​ Risk Factors: HBV, HCV, chronic alcoholism, NAFLD. ​ Symptoms: Weight loss, anorexia, jaundice, abdominal pain, and a palpable mass. ​ Prognosis: Poor unless detected early. Complications of Liver Disorders 1. Portal Hypertension ​ Definition: Abnormally high pressure in the portal venous system (normal ~5 mmHg; portal hypertension >12 mmHg). ​ Cause: Blockage or resistance to blood flow through the liver, typically caused by cirrhosis (scarring of the liver), thrombosis, or inflammation. ​ Consequences: ○​ Esophageal Varices: ​ Thin-walled veins in the esophagus dilate due to increased pressure. ​ Can rupture, causing life-threatening bleeding (vomiting blood or black stools). ​ About 40% of cirrhosis patients develop varices, and ruptures are fatal in many cases. ○​ Splenomegaly: ​ Enlarged spleen due to backflow of blood. ​ Causes destruction of blood cells, leading to anemia, low platelets, and increased bleeding risk. ○​ Caput Medusae: ​ Visible dilated veins on the abdomen due to blood rerouting through superficial veins. 2. Ascites ​ Definition: Accumulation of fluid in the abdominal cavity. ​ Causes: ○​ Portal Hypertension: High pressure pushes fluid out of blood vessels into the abdomen. ○​ Low Albumin: The liver produces albumin, a protein that maintains fluid balance. When albumin levels drop, fluid leaks into tissues. ○​ Salt and water retention exacerbates the problem. ​ Symptoms: ○​ Distended abdomen, weight gain (can hold 15+ liters of fluid). ○​ Difficulty breathing (fluid presses on the diaphragm). ○​ Loss of appetite and discomfort. ​ Complications: ○​ Spontaneous Bacterial Peritonitis (SBP): Infection of the fluid, causing fever and abdominal pain. ○​ Poor prognosis: 25% of patients with ascites die within a year if untreated. ​ Treatment: ○​ Diuretics to remove excess fluid. ○​ Paracentesis (draining fluid with a needle) for severe cases. ○​ Low-sodium diet and fluid restrictions. 3. Hepatic Encephalopathy ​ Definition: A decline in brain function due to toxins (mainly ammonia) building up in the blood when the liver fails to filter them out. ​ Cause: ○​ Liver dysfunction or portal hypertension allows ammonia and other toxins to bypass the liver and enter circulation. ​ Symptoms: ○​ Early Signs: ​ Subtle personality changes, irritability, memory problems, difficulty concentrating, and hand tremors (asterixis). ○​ Advanced Signs: ​ Confusion, stupor, drowsiness, slurred speech, and coma. ​ Treatment: ○​ Lactulose: A laxative that reduces ammonia levels by trapping it in the intestines. ○​ Antibiotics: To reduce ammonia-producing gut bacteria. ○​ Protein restriction in severe cases. 4. Jaundice ​ Definition: Yellowing of the skin, eyes, and mucous membranes due to excess bilirubin in the blood. ​ Cause: ○​ Pre-hepatic Jaundice: Excessive destruction of red blood cells (hemolysis). ○​ Hepatocellular Jaundice: Liver cells fail to process bilirubin due to damage (e.g., hepatitis, cirrhosis). ○​ Post-hepatic Jaundice: Blockage of bile ducts (e.g., gallstones, tumors) prevents bilirubin excretion. ​ Symptoms: ○​ Yellowing of skin and eyes. ○​ Dark urine (bilirubin excreted in urine). ○​ Pale or clay-colored stool (lack of bile in stool). ​ Treatment: ○​ Address the underlying cause (e.g., unblock bile ducts, treat liver disease). 5. Hepatorenal Syndrome ​ Definition: Kidney failure that occurs due to severe liver disease. ​ Cause: ○​ Advanced liver disease causes poor blood circulation, leading to reduced kidney perfusion. ○​ The exact mechanism is unclear but involves constriction of kidney blood vessels. ​ Symptoms: ○​ Acute Symptoms: Sudden onset of kidney failure (oliguria = very low urine output). ○​ Low blood pressure (systolic 40, obesity, rapid weight loss, pregnancy, family history, high cholesterol. ​ Symptoms: ○​ Often asymptomatic unless a stone blocks the bile duct. ○​ Biliary Colic: Sudden, intense pain in the upper right abdomen, often after a fatty meal. Pain may radiate to the back or right shoulder. ○​ Nausea, vomiting, bloating, and indigestion. ​ Complications: ○​ Cholecystitis: Inflammation of the gallbladder (see below). ○​ Choledocholithiasis: Stones in the common bile duct, leading to jaundice and infection. ○​ Pancreatitis: Inflammation of the pancreas if a stone blocks the pancreatic duct. ​ Treatment: ○​ Asymptomatic stones: No treatment needed. ○​ Symptomatic stones: ​ Pain relief, dietary modifications (low-fat diet). ​ Surgery (laparoscopic cholecystectomy = gallbladder removal). ​ Non-surgical: Medications to dissolve stones or shock wave therapy (lithotripsy). 2. Cholecystitis ​ Definition: Inflammation of the gallbladder, often due to a gallstone blocking the cystic duct. ​ Types: ○​ Acute Cholecystitis: Sudden and severe inflammation. ○​ Chronic Cholecystitis: Repeated episodes leading to thickening and scarring of the gallbladder. ​ Causes: ○​ Gallstone obstruction (90% of cases). ○​ Infection or trauma. ​ Symptoms: ○​ Severe, constant pain in the upper right abdomen (lasting hours to days). ○​ Fever, nausea, vomiting. ○​ Pain worsens after eating fatty foods. ○​ Tenderness in the upper right abdomen (Murphy’s sign: Pain when taking a deep breath during palpation). ​ Complications: ○​ Gangrene: Tissue death due to lack of blood supply. ○​ Perforation: Rupture of the gallbladder, leading to peritonitis (life-threatening infection). ​ Treatment: ○​ Antibiotics for infection. ○​ Pain relief. ○​ Surgery to remove the gallbladder (cholecystectomy). 3. Choledocholithiasis ​ Definition: Gallstones in the common bile duct, blocking the flow of bile. ​ Symptoms: ○​ Jaundice (yellowing of the skin and eyes). ○​ Dark urine, pale stools. ○​ Abdominal pain, fever, and chills (if infection develops). ​ Complications: ○​ Biliary obstruction can lead to severe infections like cholangitis (inflammation of the bile ducts). ​ Treatment: ○​ Endoscopic removal of stones (ERCP). ○​ Surgery if necessary. 4. Cholangitis ​ Definition: Infection and inflammation of the bile ducts, often due to a blocked duct. ​ Symptoms: ○​ Charcot’s Triad: Fever, jaundice, and right upper quadrant pain. ○​ Severe cases: Hypotension (low blood pressure) and confusion (Reynold’s pentad). ​ Treatment: ○​ Antibiotics for infection. ○​ ERCP to relieve obstruction. 5. Gallbladder Cancer ​ Definition: Rare cancer originating in the gallbladder, often detected late. ​ Risk Factors: Chronic gallstones, gallbladder polyps, and chronic cholecystitis. ​ Symptoms: ○​ Persistent abdominal pain, jaundice, weight loss, and loss of appetite. ​ Treatment: ○​ Surgery if detected early. ○​ Advanced cases may require chemotherapy or palliative care.​ The Pancreas Functions: 1.​ Exocrine Function (Digestive Role): ○​ Secretes pancreatic juice (~1.5–3 liters/day) into the duodenum through the pancreatic duct. ○​ Components of pancreatic juice: ​ Enzymes: ​ Lipase: Breaks down fats. ​ Amylase: Breaks down carbohydrates. ​ Proteases (e.g., trypsin): Break down proteins. ​ Bicarbonate: Neutralizes stomach acid to protect the intestinal lining. 2.​ Endocrine Function (Hormonal Role): ○​ Produces hormones secreted into the bloodstream: ​ Insulin: Lowers blood sugar by helping glucose enter cells. ​ Glucagon: Raises blood sugar by stimulating glucose release from the liver. Disorders of the Pancreas 1. Acute Pancreatitis ​ Definition: Sudden inflammation of the pancreas, often reversible. ​ Causes: ○​ Gallstones: Block pancreatic enzymes from leaving the pancreas. ○​ Alcohol abuse: Irritates the pancreas and damages cells. ○​ Other: Trauma, infections, certain medications, and high triglycerides. ​ Pathophysiology: ○​ Premature activation of digestive enzymes within the pancreas leads to self-digestion of pancreatic tissue. ○​ This causes inflammation, necrosis, and, in severe cases, systemic complications. ​ Symptoms: ○​ Severe upper abdominal pain (radiates to the back, worsens after eating). ○​ Nausea, vomiting, and abdominal bloating. ○​ Fever, rapid heart rate, and low blood pressure. ​ Complications: ○​ Pancreatic necrosis (tissue death). ○​ Pseudocysts (fluid-filled sacs). ○​ Systemic complications: Sepsis, hypovolemic shock, and organ failure. ​ Treatment: ○​ Pain management and IV fluids. ○​ NPO (nothing by mouth) to rest the pancreas. ○​ Antibiotics for infection if necrosis occurs. ○​ Surgery or drainage for severe complications (e.g., pseudocysts). 2. Chronic Pancreatitis ​ Definition: Long-term inflammation of the pancreas causing permanent damage. ​ Causes: ○​ Chronic alcohol abuse (most common). ○​ Genetic factors (e.g., cystic fibrosis). ○​ Recurrent acute pancreatitis. ​ Pathophysiology: ○​ Ongoing inflammation leads to fibrosis (scarring), calcification, and loss of pancreatic function. ​ Symptoms: ○​ Persistent or recurrent upper abdominal pain. ○​ Pain worsens after eating and may radiate to the back. ○​ Steatorrhea (fatty, foul-smelling stools due to fat malabsorption). ○​ Weight loss and malnutrition due to poor digestion. ​ Complications: ○​ Diabetes (loss of insulin-producing cells). ○​ Pancreatic cancer. ​ Treatment: ○​ Avoid alcohol and smoking. ○​ Pancreatic enzyme replacement therapy (to aid digestion). ○​ Pain management. ○​ Surgery for severe cases (e.g., removing damaged tissue or draining pseudocysts). 3. Pancreatic Cancer ​ Definition: Malignant tumor of the pancreas, often detected late due to vague symptoms. ​ Risk Factors: ○​ Chronic pancreatitis, diabetes, smoking, obesity, family history. ​ Symptoms: ○​ Early signs: Vague abdominal discomfort, nausea, fatigue. ○​ Late signs: ​ Jaundice (due to bile duct obstruction). ​ Weight loss and loss of appetite. ​ Persistent abdominal or back pain. ​ Dark urine and pale stools. ​ Complications: ○​ Rapid spread to other organs (liver, lungs). ○​ Bile duct obstruction, leading to jaundice. ​ Treatment: ○​ Early-stage: Surgery (e.g., Whipple procedure). ○​ Advanced-stage: Chemotherapy, radiation therapy, or palliative care. 4. Diabetes Mellitus (Linked to the Pancreas) ​ Type 1 Diabetes: Autoimmune destruction of insulin-producing cells in the pancreas. ​ Type 2 Diabetes: Insulin resistance combined with decreased insulin production.