Digestive System Chapter 6 PDF

Chapter 6: The Digestive System (Gastrointestinal) Functions of Digestive System: - Breaks down food physically (mouth) and chemically (salivary glands) - Prepares food for absorption by cells of the body - Eliminates waste substances Order of Digestion: Upper GI tract: 1. Ora...

Chapter 6: The Digestive System (Gastrointestinal) Functions of Digestive System: - Breaks down food physically (mouth) and chemically (salivary glands) - Prepares food for absorption by cells of the body - Eliminates waste substances Order of Digestion: Upper GI tract: 1. Oral Cavity (Mouth) - Cheeks (bucca) - Lips, tongue, teeth - Salivary glands 2. Pharynx (throat) 3. Esophagus 4. Stomach Accessory Organs: 1. Liver 2. Pancreas: Small Intestine: 1. Duodenum 2. Jejunum 3. Ileum Large Intestine: 1. Cecum 2. Ascending Colon 3. Transverse Colon 4. Descending Colon 5. Sigmoid colon 6. Rectum 7. Anus (feces expelled) Terms: Bilirubin Yellowish pigment formed in destruction of erythrocytes taken up by liver, excreted in feces (elevated:jaundice:liver disease) Bolus Mass of masticated food for swallowing Exocrine Secretes products to surface of organ or tissue or vessel Sphincter Muscle fibers constricting passage of natural body opening (ie. esophageal sphincter constricts or closes food passing in stomach to prevent reflux of stomach content to travel up to esophagus, damaging its lining) Triglycerides True fat compound: 1 glycerol, 3 fatty acids (combine with proteins for energy after liver synthesis) 1. Teeth: Essential for mastication (chewing), breaking food into smaller pieces, embedded in gingiva Composed of: ○ Enamel (outer layer) ○ Dentin (main structure) ○ Pulp (innermost, containing nerves and blood vessels) 2. Tongue: Manipulates food during chewing and aids in (swallowing=deglutition) Has papillae with taste buds for sensing 4 basic tastes: sweet, sour, salty, and bitter. Assists in speech production. 3. Hard and Soft Palates (lined with mucus membranes) Hard palate: anterior roof of the mouth. Soft palate: posterior roof, separating mouth from the nasopharynx. 4. Pharynx (Throat): Covered by Uvula (little hanging flap in back of mouth) Passageway for food and air, and a resonating chamber for speech sounds. Leads to the esophagus and trachea. During swallowing, epiglottis covers the trachea to direct food into the esophagus. 5. Esophagus: Muscular tube that guides food from the pharynx to the stomach. Prevents backflow of stomach contents through the lower esophageal (cardiac) sphincter. 6. Stomach (LUQ of abdominal cavity) Functions as a food reservoir and continues mechanical and chemical digestion. Sections include the fundus, body, and pylorus (where most digestion occurs). Interior lining has rugae that release digestive enzymes and hydrochloric acid (HCl). Food turned to chyme; moves through pyloric sphincter into small intestine (regulates speed & move) *Food propelled through entire GI tract by muscle contractions (peristalsis) 7. Small Intestine: Duodenum (10 inches): Receives chyme from the stomach and bile from accessory organs. Jejunum (8 feet): Primary site for nutrient absorption. Ileum (12 feet): Continues absorption and connects to the large intestine Functions: Digestion: Completed with the help of enzymes and secretions from the pancreas and liver, Absorption: Occurs through tiny, fingerlike projections called villi, which help nutrients enter the bloodstream and lymphatic system. Ileocecal Valve: A sphincter muscle at the terminal end of the small intestine controls the passage of undigested material into the large intestine. 9. Large Intestine: Primary Function: water absorption and feces Divisions: 1. Cecum: First part of the large intestine, connected to the ileum via the ileocecal valve. Appendix: A small worm structure outside cecum, prone inflammation (appendicitis). 2. Colon: Divided into four sections: Ascending Colon: Extends from the cecum to the liver, forming the hepatic flexure. Transverse Colon: Extends across abdomen, turning downward at splenic flexure. Descending Colon: Continues down the left side of the abdomen. Sigmoid Colon: S-shaped section leading to the rectum. 3. Rectum: Final storage area for waste before elimination. 4. Anus: Terminal end for waste expulsion. Accessory Organs: 10. Liver Functions: 1. Largest Glandular Organ (RUQ and LUQ) 2. Produces bile= breaks down fats 3. Removes glucose from blood, converts it to glycogen for storage (regulates levels) 4. Stores essential vitamins (B12, A, D, E, K). 5. Detoxifies harmful substances. 6. Destroys old erythrocytes (red blood cells) and releases bilirubin. 7. Synthesizes proteins like albumin (fluid balance) and clotting factors (prothrombin, fibrinogen). 11. Gallbladder: 1. Stores and releases bile into the duodenum when needed though Bile Duct System: 1. Bile flows from the liver through the right and left hepatic ducts. 2. Common hepatic duct merges with cystic duct of the gallbladder to form common bile duct. 3. The common bile duct releases bile into the duodenum to aid in fat digestion. 12. Pancreas: Secretes enzymes that aid in the digestion of carbohydrates, proteins, and fats. 1. Endocrine Function: Secretes insulin into the bloodstream to regulate blood glucose levels 2. Exocrine Function: Produces digestive enzymes (trypsin for proteins, amylase for starch, lipase for fats) Digestive Terms: Oro/o Mouth Stomat/o Gloss/o Tongue Lingu/o Bucc/o Cheek (bochecha) Cheil/o Lip Labi/o Sial/o Saliva/Salivary gland Enter/o Intestine (usually small) Proct/o Anus, rectum (i.e. proctologist 4 men) An/o Anus Hepat/o Liver Cholangi/o Bile vessel Chol/e Bile gall Cholecyst/o Gallbladder Sigmoid/o Sigmoid Colon Choledoch/o Bile duct Iasis Abnormal condition caused by something specified Orexia Appetite (i.e. Anorexia, lack thereof) Pepsia Digestion Phagia Swallowing, eating Prandial Meal Digestive Diseases: Peptic Ulcer - Definition: Common ulcers (open sores), developing mainly in stomach, duodenum, less Disease (PUD) in esophagus - Common Cause: erosion of mucous membrane caused by Helicobacter pylori bacteria (acid reflux causes ulcer moving into duodenum) - Risk factors: smokers (increases H pylori) , chew tobacco, stress, caffeine, steroids, aspirin, NSAIDS (non steroids), - Treatment: antacids, kill H. Pylori. But if untreated, hole (perforation) occurs, if leaks to abdominal cavity, leads to peritonitis (inflammation of peritoneum) Hernia Steps: *perforation of Abdominal: tissue through wall 1. Inguinal Hernia: groin area, soft lump hardly noticeable, can be pushed back in early of cavity its stages, minimal pain contained in 2. Strangulated Hernia: occurs if blood supply of hernia cut off bc of pressure, (necrosis with gangrene (tissue death)) 3. Umbilical Hernia: common in obese women, many pregnancies, happen in babies (congenital), early childhood Diaphragm Nic: 4. Diaphragmatic hernia: congenital disorder 5. Hiatal Hernia: lower esophagus & top of stomach slide through opening (hiatus) in the diaphragm into thorax; stomach acid back to esophagus; causes heartburn, chest pain, swallowing difficulty, if prolonged, gastroesophageal reflux disease (GERD) 1. Treatment: Hernioplasty with suture of abdominal wall (herniorrhaphy) Hepatitis - Inflammation of the liver caused by exposure to toxic substances (e.g. alcohol), bile duct obstructions, metabolic/autoimmune disease, bacterial/viral infections - Viral Hepatitis: major public health concern (easy transmission) - 5 types: 1. Hepatitis A (infectious): ingestion of contaminated food, water, milk -> poor sanitation 2. Hepatitis B (Serum): transmitted via blood, sex; healthcare workers at risk; vaccine available 3. Hepatitis C: Transmitted through blood transfusions, parenteral routes, no vaccine, can lead to chronic liver issues - No cure, in case of cirrhosis; liver transplantation - Symptom: Jaundice Diverticulosis - Small blister-like pocket called diverticula form in inner lining of li, sigmoid colon - Symptoms: Pain LLQ, extreme constipation (obstipation), fever, abdominal swelling, blood bowels, anemia - Treatment: rest colon, antibiotics, diet, if extreme surgery bc can lead to peritonitis (rupture) Oncology - Arises from epithelial/mucosal lining of stomach forming cancerous glandular tumor (gastric adenocarcinoma) - Symptoms: persistent indigestion - Related GI Carcinomas: esophageal, hepatocellular, pancreatic carcinomas Common type of cancer in US: Colorectal Cancer - Developed in epithelial lining of colon/rectum -> indigestion Appendicitis - Bacterial infection, or fecalith - Pain in RLQ in McBurney Point (if relief, ruptured) - Fever, malaise, diarrhea, constipation, tachycardia - Surgery 48 hours, of not, rupture peritonitis as feces released into peritoneal cavity Ascites - Abnormal fluid accumulation in peritoneal cavity as result of chronic liver disease Borborygmus - Rumbling, gurgling loud noise caused by passed gas through liquid contents of intestine Cachexia/ - Wasting, extreme weight and muscle lost, malnutrition Wasting Syndrome Cholelithiasis - Gallstones in gallbladder - May be asymptomatic, but if symptoms: - biliary colic: pain from bile duct obstruction - RUQ abdominal pain radiating to shoulder & back - Nausea, vomiting after fatty meals - Treatment: -Surgical Laparoscopic Cholecystectomy (minimally invasive remove gallbladder) -Nonsurgical: Extracorporeal Shock-Wave Lithotripsy (ESWL), & Cholesterol inhibitors Choledocholithiasis - Gallstones in common bile duct (choledochus) - Treatment: - Surgical Choledocholithotom, ERCP remove common bile duct (& take out stones) Cirrhosis - Scarring & dysfunction of liver caused by chronic liver disease (causes jaundice) Crohn's Disease - Autoimmune Form of IBD, usually of ilium, but can be entire inflamed digestive tract Dysentery - GI walls inflammation, especially colon; indigestion of contaminants, bacteria, parasites - Bloody diarrhea and mucus Flatus - Gas in GI tract GERD - Backflow of gastric contents to esophagus bc of sphincter muscle malfunction Halitosis - Foul smelling breath Hematemesis - Vomiting blood (hema: blood, emesis: vomit) Hemorrhoids - Swollen varicose veins in anorectal region Intestinal - Bowel blockage of intestine, cannot move through tract Obstruction IBS - Altered bowel function: constipation, diarrhea Liver Function Test - Examines levels of enzymes, bilirubin, proteins Malabsorption - Small intestine impaired passage of nutrields, minerals, fluid through villi to blood/lymph syndrome Melena - Dark feces (usually with digested blood from bleeding esophagus/stomach) Oral Leukoplakia - White patch formation in mucous membrane of tongue, lips, cheeks Pyloric Stenosis - Narrowing pyloric sphincter, causing obstruction blocking food flow to small intestine Regurgitation - Backward flow (return from solid/fluids) to mouth from stomach Ulcerative Colitis - Chronic inflammatory disease of colon, beginning colon Volvulus Twisting Bowel on itself causing obstruction Gastrointestinal Endoscopy Visual examination with magnifying lens & light (endoscope) to identify abnormalities, ulcerations, bleeding, tumors Stool culture Identifies microorganisms/parasites in feces causing gastro infection Stool Guaiac Identifies hidden blood in feces (Hemoccult) Lower Gastrointestinal series X-ray of rectum, colon, barium into rectum (lower GI series, barium enema) Upper Gastrointestinal Series X-ray images of esophagus, stomach, small intestine (barium swallow) Oral Cholecystography Radiographic images taken of gallbladder after iodine tablet Magnetic Resonance Special MRI for liver, gallbladder, bile ducts, pancreas, pancreatic duct Cholangiopancreatography Abdominal Ultrasound visual of aorta, liver, gallbladder, bile ducts, pancreas, kidney, ureters, bladder Ileorectal Anastomosis Joining ileum and rectum after total colectomy (treats ulcerative colitis) Vs Intestinal Anastomosis Vs surgical connection of the intestines Appendectomy Open 3 straight diagonal, (Open & Laparoscopic) Minimally invasive with monitor incisions to remove appendix Bariatric - Vertical Banded Gastroplasty: vertical stapling of upper stomach by 1. vertical banded esophagus band restricts food consumption, delays passage (feel full) gastroplasty - Roux-en-Y Gastric Bypass: stabled stomach, short jejunum, connected to 2. roux-en-Y gastric bypass gastric pouch, decreases pathway of food, reduces absorption of calories & fats Colostomy Forms opening (stoma), connects healthy end of colon to a bag Lithotripsy/Extra shock wave Breaks kidney stones through shock waves Paracentesis Remove fluid from abdomen Polypectomy Polyp excision to check if cancerous small growth Proctosigmoidoscope Examines rectum and sigmoid colon Nasogastric Intubation Inserts nasogastric tube through nose to stomach to feel relief; removes gas, food, can also be feeding tube