Presentation on theme: "Pancreas Oblong gland that lies posterior to the greater curvature of the stomach. Connected by ducts to the duodenum. Composed of clusters of glandular."— Presentation transcript:
2PancreasOblong gland that lies posterior to the greater curvature of the stomach.Connected by ducts to the duodenum.Composed of clusters of glandular epithelial cells.Two main types of Pancreatic Cells:Pancreatic Islets-Islets of Langerhans (1%)Hormones: insulin, glucagon, somatostatinAcini Cells (99%)Digestive pancreatic enzymes
4Pancreatic JuiceAlkaline mixture of fluid and digestive enzymes from the acini cells.Pancreatic Digestive Enzymes:Pancreatic Amylase - CHO digestionPancreatic Lipase - Fat digestionChymotrypsin-Trypsin-Carboxypeptidase - Protein digestionNucleases - Nucleic Acid digestionRegulated by the intestinal hormones: Secretin and Cholecystokinin.
5Liver Located just under the diaphragm on the right side of the body. Largest organ of the abdominopelvic cavity.Weighs about 1.4 kgs (3 lbs).Nicknamed the chemical factory of the body.Completely covered by the peritoneum and a dense layer of connective tissue beneath the peritoneum.
6Anatomy of the Liver Right Lobe - largest lobe of the liver. Located on the lateral-right side of the bodyCaudate Lobe - posterior portion of right lobeQuadrate Lobe - inferior portion of right lobeLeft Lobe - smaller, medial lobe of the liver.Falciform Ligament - separates the right and left lobes of the liver and anchors it to the diaphragm and anterior abdominal wall.
8Lobules of the Liver Smaller functional units of the liver. Hepatocytes in the lobules produce and secrete a yellowish, brownish, or olive green liquid called BILE (1 quart daily).Composed of bile salts and pigments, lecithin, and several ions.pH ofExcretory product and digestive secretion.Assists in the breakdown of fat molecules (Emulsification).Principle bile pigment is bilirubin.
9Functions of the Liver Metabolism of CHO, fats, and proteins Removal of drugs and hormonesExcretion of bileSynthesis of bile saltsStorage of vitamins, minerals, and food moleculesPhagocytosis of old, worn out RBCs and WBCsActivation of Vitamin D
10The Gallbladder A pear shaped sac about 7 - 10 cm long. Located on the bottom surface of the liver.Stores and concentrates bile until needed by the small intestine for the emulsification of fat.
13The Small IntestineDuodenum - the beginning of the small intestine. Is attached to the stomach.first 12 to 14 inchesJejunum - the portion of the small intestine after the duodenum.normally about 8 ft. longIleum - the final portion of the small intestine.about 12 ft. longileocecal valve
17Chemical Digestion of the Small Intestine Very complex process with a series of chemical events that results in the breakdown of carbohydrates, fats, and proteins.Result of the collective effort of pancreatic juice, bile, and intestinal juice.Results in absorption - passage of digested nutrients into the blood or lymph.
18Mechanisms to Increase Absorption by the Small Intestines Folds in the intestinal walls of the mucosa layer of tissue .(Plicae Circulares)Villi arrangement of tissue of mucosa layer.Lacteals - blood capillaries and lymphatic vessels associated with each villiMicrovilli arrangement of epithelial cells of the mucosa.
23Absorption in the Small Intestine 90% of absorption takes place within the small intestine.other 10% occurs in the stomach and large intestineAbsorption of nutrients occurs through the villi by means of:diffusion - facilitated diffusionosmosis - active transport
26Additional Components of the Small Intestine Intestinal Juice - slightly alkaline secretion (pH 7.6) secreted by intestinal glands.rapidly absorbed by the villi and provides a mechanism for absorption of substances in chymePeyer’s Patches - lymphatic glands of the small intestine.Brunner’s Glands - mucus secreting glands of the small intestine.
27Mechanical Digestion of the Small Intestine Segmentation - localized contraction of muscles of the small intestine in areas containing foodrate of about contractions/minutesloshing of chyme back and forth within the intestinal lumenPeristalsis - rhythmical contraction of muscles of the small intestines that propels chyme through the intestinal tract
28The Large Intestine About 1.5 m (5 ft) in length. Cecum - beginning of the large intestineVermiform AppendixColon - large tube-like portion of large intestineAscending Colon Transverse ColonDescending Colon Sigmoid ColonRectumAnal Canal --->Anus
30Functions of the Large Intestine Completes absorptionTeabsorption of waterManufacture certain vitaminsFormation of fecesExpulsion of feces from the body
31Histology of the Large Intestine Walls of the large intestine contain no villi or permanent circular folds in the mucosa layer.Epithelial tissue layer contain numerous goblet cells (secretes mucus).Lubricates the colonic contents as it passes through the large intestine.
32Haustra - series of characteristic pouch like structures that run the entire length of the colon. Taenia Coli - bands of smooth muscle that are arranged longitudinally along the length of the colon.Epiplotic Appendages - small fat filled appendages suspended from the Taenia Coli.Anal Columns - parallel ridges of mucosa in the anal canal which reduces friction with feces during defecation.
35Mechanical Digestion in the Large Intestine Haustral Churning - the relaxation and contraction of the individual segments of the colon.Peristalsis - rhythmical contraction of the colon that moves the contents along through the length of the colon.Mass Peristalsis - a strong peristaltic wave that begins about the middle of the transverse colon and drives the colonic contents into the rectum.
36Chemical Digestion in the Large Intestine last stage of digestiondue to bacterial action in the large intestinebacteria ferment any remaining carbohydrates and release hydrogen, carbon dioxide, and methane gasalso converts any remaining proteins into amino acidsabsorbs any remaining water and electrolytes
37Feces Formation in the Large Intestine by the time chyme has remained in the large intestine for hours it has become a solid or semi-solid and is known as FECESconsists of water, inorganic salts, sloughed off epithelial cells, products from bacterial decomposition, and indigestible parts of foodDefecationThe emptying of the rectum.Diarrhea - frequent defecation of liquid feces.Constipation - infrequent or difficult defecation. Stools are hard and dry.
38Digestive System Diseases and Homeostatic Imbalances Cirrhosis of the LiverDistorted or scarred liver tissue due to chronic inflammation.Commonly caused by hepatitis, chemical exposure, parasites, and alcoholism.Symptoms include: jaundice, bleeding, edema, and increased sensitivity to drugs and chemicals.
39Gall Stones Appendicitis Inflammation of the vermiform appendix. May be caused by an obstruction of the lumen of the appendix by fecal material, a foreign body, stenosis, a kinking of the organ, or carcinoma.Gall StonesCrystallization of bile in the gallbladder.Can block the bile duct causing intense pain.Usually treated with gall stone dissolving drugs, lithotripsy, or surgery.
40Tumors of the Digestive Tract Can occur in all areas of the G.I. tract.Can be malignant or benign. Often no smptoms.Colorectal Cancer3rd most common cause of cancer for both males and females.Overall mortality rate is over 60%.Factors contributing to colorectal cancer include genetic predisposition, diet high in fat, protein, insufficient dietary fiber, and low calcium and selenium in the diet.
41Hepatitis Inflammation of the liver. Can be caused by viruses, drugs, and certain chemicals including steroids and alcohol.Many different types of Hepatitis including:Hepatitis A (Infectious Hepatitis)Hepatitis B (Serum Hepatitis)Non A Non B (NANB) Hepatitis
42Hepatitis A Infectious hepatitis Caused by Hepatitis A virus Spread by fecal contamination of food, clothing, toys, eating utensils, etc.Generally a mild disease of children and young adultsCharacterized by anorexia, malaise, jaundice, nausea, diarrhea, fever, and chills
43Non A Non B Hepatitis Hepatitis B Serum hepatitis Caused by the Hepatitis B virusTransmitted by sexual contact, contaminated syringes, transfusion equipment, saliva, tears, and puncture wounds in the skinCan produce cirrhosis and possibly cancer of the liverNon A Non B HepatitisOther types of hepatitis that can not be traced to either the A or B virus (up to about virus H in the alphabet).Often spread by blood transfusions.Can cause cirrhosis and possibly cancer of the liver.
44Obesity Clinically classified as obese if: > 30% of projected body weight as determined height and frame sizedoesn’t factor in Body CompositionCurrently over 50% of U.S. population is clinically classified as obese.14% of all male cancers linked to obesity20% of all female cancers linked to obesityDiabetes mellitus rates continue to rise dramatically in the U.S.
45A serious risk factor for: U.S. surgeon general has said obesity is the second most serious threat to the health of Americans.A serious risk factor for:Heart Disease - DiabetesHypertension - CancersRespiratory Disorders - Joint ProblemsEndocrine DisordersGastrointestinal DisordersUrinary and Reproductive System Disorders
46Peptic UlcersCrater-like lesions that develop in the gastrointestinal tract.Gastric Ulcers ---> StomachDuodenal Ulcers ---> DuodenumCommonly caused by hypersecretion of gastric juices and acids.Contributing factors include: stress, cigarette smoking, certain foods, some medications, and bacterial infections.