1. Announcements No Class on November 23 rd Want some Independent Study Credits? SEE ME!

2. Renal Pelvis ----> Ureter -----> Bladder Mucosa: Transitional epithelium - lamina propria Muscularis: Smooth muscle Longitudinal inner layer Circular outer layer Adventitia

3. URETER 25.

4. URETER

5. BLADDER http://www.visualsunlimited.com/browse/vu306/vu306638.html

6. Urethra Epithelium: Female: Transitional----> Stratified Squamous Male: Transitional----> Stratified or Pseudostratified Columnar Stratified Squamous

7. KIDNEY DIALYSIS METHODS

8. Digestive System Alimentary Canal and Associated Organs MouthTongue EsophagusTeeth StomachSalivary Glands Small IntestinePancreas Large IntestineLiver Gall Bladder

9. Alimentary Canal General Structure from Esophagus ---> Anus Mucosa: Epithelium (varied composition) Lamina Propria Muscularis Mucosa (smooth muscle) Submucosa: Dense irregular connective tissue Muscularis externa: Two layers of smooth muscle Serosa: simple squamous epithelium, connective tissue

10. Function of the Alimentary Canal Barrier: between internal and external environments Immunological Defense: site of lymphatic tissue Motility: movement of food Secretion: enzymes, mucous, acid, antibodies Absorption: products of digestion

11. Barrier- Epithelium Oral Cavity : parakeratinized epithelium- most superficial cells do not lose nuclei tongue, gums, hard palate Connective tissue papilla

12. Barrier- Epithelium Esophagus : stratified squamous epithelium Small and Large Intestine- tight junctions between columnar cells of simple epithelium

14. Barrett’s Esophagus http://content.revolutionhealth.com/contentimages/images-image_popup-barrettsesophagus.jpg -Damage to the lining of the esophagus due to leakage of stomach acid into the esophagus Stratified Squamous Epithelium Simple Columnar Epithelium

15. Esophagus: Normal stratified squamous epithelium

16. Barrett’s Esophagus

17. Simple columnar epithelium, presence of goblet cells

18. What if the barrier is breached? Immunological Defense Tonsils: ring of lymphatic tissue (lymphatic nodules or follicles) at entrance to respiratory and digestive tracts micro.magnet.fsu.edu/optics/intelplay/gallery...

19. Adenoids: lymphatic tissue located high on the posterior wall of the pharynx. - similar to tonsils - clear antigens from air - reduced in adults - can be enlarged / inflamed SYMPTOMS: -mouth breathing -snoring -bad breath -chronic runny nose -sleep apnea -pulmonary hypertension -right-sided heart failure

20. Immunological Defense Gut-associated lymphatic tissue (GALT): diffuse lymphatic tissue and lymphatic nodules in lamina propria of small and large intestine Striking in Ileum and Appendix => Peyer’s Patches MALT=Mucous associated lymphatic Tissue

21. Immunological Defense: Lymphatic Tissue Plasma Cells secrete a special form of antibody, ==> secreted IgA -Dimeric -Linked via J chain and secretory component -More stable -More resistant to enzymatic digestion -in saliva, milk, and mucous membranes of respiratory and digestive tracts

22. Possible modes of defense mediated by IgA binding to its receptor, pIgR, (the secretory component, SC). (a)pIgR-driven export of dimeric IgA with J chain (IgA+J) (b)Neutralization of infecting virus and transport of viral products from the lumen. (c)Intracellular neutralization of endotoxin (LPS) from Gram-negative bacteria. (d)Clearance of antigen (Ag) that has breached the mucosal barrier. From Trends Immunol. 2004, 25:150-57.

23. www.bu.edu/histology/p/12001oba.htm Immunological Defense Peyer’s Patches Lymph nodules capped by specialized epithelial cells =>M Cells

24. M Cells - Follicle-Associated Epithelium (FAE): epithelial cells associated with lymph nodules of MALT - look for absence of goblet cells over Peyer’s Patch - apical surface microfolds rather than microvilli - connected to neighbors with tight junctions

25. M Cells -have extensive inpocketings of basal membrane containing T and B lymphocytes www.rcai.riken.go.jp/eng/group/epi/

26. M Cells: specialized for transepithelial transport: deliver intact foreign antigens and microorganisms from lumen to immune cells

27. Motility Muscularis Mucosa : thin layer of smooth muscle responsible for moving the mucosa

28. Motility Muscularis Externa: mixes, propels contents of lumen 2 thick layers of smooth muscle inner layer=> circularly-oriented layer -tight spiral outer layer=>longitudinally-oriented layer -loose spiral Between muscle layers- Nervous innervation Myenteric plexis (Auerbach’s plexis)

29. Motility : Muscularis Externa

31. Motility MUSCULARIS EXTERNA EXCEPTIONS: SKELETAL MUSCLE in proximal esophagus (upper 1/3) & anus

32. MUSCULARIS EXTERNA EXCEPTIONS: Teniae Coli: 3 thickened bands of longitudinal layer of smooth muscle in the large intestine- Lumen

33. Secretion - carried out by epithelial cells and associated glands - secretions include: Antibodies: IgA Lubrication substances- Mucous, Goblet cells! Aid for digestion: hydrochloric acid & enzymes Hormones Water -secretions from salivary glands, stomach, small and large intestine

34. Before we discuss secretions: A PAUSE FOR A BIT OF GROSS ANATOMY!

35. Anatomy of the Stomach 3 regions: Cardiac Pyloric Fundic Rugae: longitudinal folds or ridges on inner surface

36. Anatomy of the Stomach 3 regions: Cardiac Pyloric Fundic Rugae: longitudinal folds or ridges on inner surface Simple columnar epithelium

37. Each stomach region has distinctive glands. Cardiac glands Pyloric glands Fundic glands -gastric pits -isthmus cell replication -neck -base or fundus

38. Anatomy of the Small Intestine 3 components: Duodenum, Jeunum, Ileum - Plicae circularis - Villi - Microvilli - Simple columnar epithelium

39. Anatomy of the Small Intestine

40. Lubrication: Mucous Secretions Esophagus- Lubrication and protection from regurgitation of acidic stomach contents Stomach- surface mucous cells; mucous protects from abrasion, contains bicarbonate; protects mucosa from acidic stomach contents (chyme) Small Intestine- goblet cells, # increases from duodenum=> ileum Large Intestine- goblet cells, # increases toward rectum

41. Specialized Cells for Stomach Secretion Surface Mucous Cells: gastic pit and neck of gastric gland PAS stain for carbohydrates millette.med.sc.edu/Lab%201%20pages/introduct...

42. Specialized Cells for Stomach Secretion Parietal (Oxyntic) Cells: - neck & deep parts of fundic glands - release HCl and intrinsic factor (B12 absorption) - large** - triangular** - acidophilic**

43. Parietal (Oxyntic) Cells Anti-parietal cell antibody

44. Parietal (Oxyntic) Cells HCl Synthesis: H + and Cl - ions pumped into intracellular canalicular system, HCl formed http://www.mfi.ku.dk/ppaulev/chapter22/images/22-10.jpg

45. Specialized Cells for Stomach Secretion Chief Cells: deep in fundic glands, protein-secreting, lots of RER, basophilic, zymogen granules Secrete pepsinogen HCl Pepsinogen---------> Pepsin

46. Specialized Cells for STOMACH Secretion Enteroendocrine cells: small - more common in gland base - pale, vesicles don’t fix well - may not reach lumen, but sample lumenal contents with microvilli -release variety of hormones into blood

47. Enteroendocrine cells

48. Specialized Cells of the Small Intestine Enterocytes (intestinal absorptive cells) Paneth cells- secrete antimicrobial substances Enteroendocrine cells- release hormones M cells- dome cells cap lymphatic nodules Goblet cells- mucous secreting

49. Enterocytes (intestinal absorptive cells) Tall columnar cells Microvilli=>striated border Epithelial specializations -Terminal web - Tight junctions Secrete Digestive Enzymes

50. Paneth Cells - base of intestinal glands - large - intense acidophilic granules - phagocytose bacteria - secrete lysozyme- digests bacterial cell wall

51. Epithelial Renewal in Stomach and Small Intestine

52. Celiac Disease (Sprue) - an inherited, autoimmune disease - lining of the small intestine damaged by eating gluten and other proteins found in wheat, barley, rye, and possibly oats. - exact cause unknown - flattening of intestinal villi http://www.nlm.nih.gov/medlineplus/ency/article/000233.htm

53. www.aafp.org/afp/20071215/afp20071215p1795-u3.jpg Normal Intestine Celiac Disease

54. Large Intestine Simple columnar epithelium Absorption of water and electrolytes Columnar absorptive cells Crypts of Lieberkuhn Goblet cells www.kumc.edu/.../histoweb/gitract/gi21.htm

55. Ulcerative Colitis -An inflammatory bowel disease that affects the lining of the large intestine (colon) and rectum. Symptoms include: - Abdominal pain and cramping and sounds - Blood and pus in the stools - Diarrhea Treatments: - Diet and nutrition - Manage stress - Medications - Surgery Histology: Presence of crypt abscesses in which the crypt epithelium breaks down and the lumen fills with cells. The lamina propria is infiltrated with leukocytes.

59. Secretion / Digestion / Absorption - Requires coordination of secretion and motility with ingestion NERVOUS AND HORMONAL SIGNALS

60. Secretion / Digestion / Absorption - Requires coordination of secretion with ingestion - Must coordinate the: Release of saliva Release of digestive enzymes Release of HCl Release of bile from gall bladder Motility of gastrointestinal tract

61. Secretion / Digestion / Absorption What signals might trigger release of hormones and digestive enzymes?

62. Gastrin secretion: release from stomach enteroendocrine cells (G cells) is stimulated by 1) peptides and amino acids in stomach lumen 2) distention of stomach wall 3) sensory inputs --> neural innervation (GRP) - Parietal cells have gastrin receptors GASTRIN RELEASE HCl RELEASE PEPSIN ACTIVATION PROTEIN DIGESTION Enterochromaffin-like cell=ECL Cell

63. Regulation Parietal Cell HCl secretion http://www.uwgi.org/gut/stomach_03.asp Gastrin produced by G cell HCl produced by parietal cell Gastrin stimulates Parietal Cells

64. Choleocystokinin (CCK): hormone released from enteroendocrine cells of small intestine is stimulated by presence of H +, amino acids, and fatty acids - Pancreatic cells have CCK receptors**( may act through neurons innervating the pancreas in humans) CCK RELEASE (INTESTINAL ENDOENDOCRINE CELLS) PANCREATIC DIGESTIVE ENZYME RELEASE DIGESTION OF CARBOHYDRATES, PROTEINS, LIPIDS IN SMALL INTESTINE