1. Human Coelomic Divisions

2.  Coelom = body cavity within lateral plate mesoderm, lined by mesothelium and partitioned during development in all amniotes  Peritoneum = mesothelium & conn. tiss. that lines the abdominal coelomic cavity and the abdom. visceral organs  Retroperitoneal = Description of something that is “outside” the peritoneum (bladder, rectum, kidneys) Coelomic Cavities

3.  Transverse septum = separates pericardial & pleuroperitoneal cavities  Pericardial Cavity = coelomic cavity around the heart  Pleuroperitoneal cavity = coelomic cavity around all visceral organs except the heart  Peritoneal cavity = abdominopelvic cavity; lined by peritoneum Coelomic Cavities

4. transverse septum

5.  Pleural / Pulmonary Cavity = coelomic cavity around the lungs evolved independently in reptiles and mammals  Pulmonary fold = (in reptiles) forms along the dorsal midline of the pleuroperitoneal cavity... grows ventrolaterally around each lung. Each lung in separate pleural cavity. Coelomic Cavities

6. Avian Cross Section gut lung heart pulmonary fold pleural cavity peritoneal cavity pericardial cavity

7.  Unique to Crocodylians Post Hepatic “Diaphragm”

8.  Coelomic (pleuroperitoneal) fold = in mammals, forms transversely across the dorsal pleuroperitoneal cavity, behind the lungs and... grows ventrally to meet the transverse septum.  Diaphragm = mucularized coelomic fold separating pleural and peritoneal cavities (anterior to the liver) Mammal Coelomic Cavities

9. Mammal Longitudinal Section lung liver pleural cavity peritoneal cavity pericardial cavity coelomic fold

10. Developing Human Coelom

11.  Coelomic fold component of diaphragm becomes muscularized.  Transverse septum component of diaphragm become the central tendon. Mammalian Diaphragm

12. Human Coelomic Divisions

13. Amniota monotremes marsupials eutherians turtles lizards & snakes crocodilians birds prehepatic diaphragm; 1 pleural cavity 2 pleural cavities * posthepatic “diaphragm” *

14.  Human Digestive System (and assoc. digestive organ) Development  General Digestive Terms  Human Digestive Tube Overview (Oral Cavity to Anus)  Human Associated Digestive Organ Development and Overview  Comparative Digestive Anatomy Digestive System

15.  Digestive tract = continuous tube; for extracting nutrients from food.  Endoderm surrounded by splanchnic mesoderm. Digestive System

16.  Endoderm = epithelial lining of most of digestive tract; usually simple epithelia.  Splanchnic mesoderm = surrounds endoderm, muscle and conn. tissues  Stomodeum = ectoderm; forms most of oral cavity & some salivary glands; stratified squamous epithelium.  Proctodeum = ectoderm; forms cloaca (posterior rectum); strat. squamous epithelium. Digestive System Development

17. Human Endoderm Development

19.  Pharyngeal Pouches = paired anterior pouches (mammals – 4, but the last one = 2 pouches; in non-mammalian gnathostomes = 6). 2 nd pouch of tetrapods forms Eustacian tube between middle ear and pharynx  Thyroid Bud - between 1 st and 2 nd pouches  Other buds that form are respiratory (Osteichthyans), hepatic, dorsal pancreatic, ventral pancreatic, & allantoic Endoderm Development

20. Human Endoderm Development thyroid bud respiratory bud yolk sac allantoic bud liver bud ventral pancreatic bud dorsal pancreatic bud four pairs pharyngeal pouches

21.  Liver = Largest coelomic organ; regulates chemical metabolism (detoxifies, glycogen storage, secretes serum albumin) & produces bile (emulsifies fats & contains RBC waste). Develops from ventral hepatic bud from duodenum in ventral mesentary. Mostly endodermal; a little lateral plate mesoderm.  Bile released into duodenum via hepatic duct then common bile duct.  Gallbladder = Stores bile; connected to bile duct through cystic duct. Human Liver

22. Vertebrate Embryo (section) gut coelom

23. Vertebrate Embryo (section) gut coelom dorsal mesentery (splanchnic mesoderm) hepatic bud ventral mesentery (splanchnic mesoderm)

24. Vertebrate Embryo (section) gut coelom dorsal mesentery (splanchnic mesoderm) liver falciform ligament (ventral mesentery)

25.  Pancreas = A distinct gland located along the duodenum with endocrine (sugar metabolism regulation) and exocrine function (digestive enzyme secretion). Endodermal. Develops from dorsal and ventral pancreatic buds off of duodenum.  Human digestive enzymes enter intestine through vent. pancreatic duct connecting to common bile duct. Human Pancreas

26. Pancreas Development

27. Human Digestive Development Develop.Adult Human Epithelial Devel. Outpouchings stomodeum anterior oral & nasal cavities parotid salivary glands pharynx (with openings) oropharynx & nasopharynx (only Eustacean tube) submandibular & sublingual salivary glands thyroid from thyroid bud trachea & lungs from resp. bud esophaguslong- stomachpresent- intestine small intestine (duodenum, jejunoileum) colon liver + ducts from hepatic bud pancreas from 2 pancreatic buds cecum / appendix ur. bladder in part from allantois proctodeumrectum-

28. 1.Epithelium – stratified squamous or simple columnar epith. around lumen. 2.Lamina Propria – loose conn. tissue. 3.Muscularis Mucosae – thin layer of smooth muscle. 4.Submucosa – loose connect. tissue. 5.Muscularis – 2-3 layers of skeletal or smooth muscle. 6.Serosa – thin layer of loose conn. tissue covered by a simple squamous epith. (coelomic mesothelium) Digestive Tube Structure (Human) Esophagus to Rectum endoderm mesoderm

29. Esophagus Section mesoderm epithelium (strat. squamous) muscularis mucosae (thin lamina propria between muscularis muc. & epithelium) submucosa muscularis (2 layers, circular & longitudinal)) serosa endoderm

30.  Sphincter – ring of muscle that can close (or partially close) a point along the digestive tube.  Peristalsis – Rhythmic contraction of smooth muscle that pushes something along the digestive tract.  Ridges/folds in digestive tube that are perpendicular to the axis of the tube = slow movement  Ridges/folds parallel to the axis of the tube = speed movement Digestive Tube Structure (Human) Esophagus to Rectum

33. Cleft Palate  Cleft Palate = Secondary palate doesn’t fuse along midline during development.

34.  Salivary Glands = Oral cavity glands produce saliva; simple cuboidal epith. Parotid Glands - ectoderm Submandibular Glands - endoderm Sublingual Glands - endoderm Human Salivary Glands

35. Human Pharynx

36. Human Oropharynx

37. Human Esophagus Section mesoderm epithelium (strat. squamous) muscularis mucosae (thin lamina propria between muscularis muc. & epithelium) submucosa muscularis (2 layers, circular & longitudinal)) serosa endoderm

38. Human Abdominal Viscera

39. Human Stomach lesser curvature greater curvature

40. Human Stomach Section Muscularis has three layers, oblique, circular, and longitudinal.

41. Human Small Intestine

43.  Plicae = folds of the intestinal epithelium.  Villi = multicellular “finger-like” projections of the intestinal epithelium.  Columnar epith. cells have microvilli. Human Small Intestine

44. Human Large Intestine

45. Rectum

46. Liver Ducts cystic duct common bile duct pancreatic duct hepatic duct

47. Human Liver Two big lobes, left & right separated by falciform ligament. Right lobe has subsidiary caudate and quadrate lobes. ventral view (anterior view)

48. Human Bile & Pancreatic Ducts

49. Human Digestive System

50.  Oral Cavity = mouth to pharynx, no separate nasal cavity in vertebrates without a secondary palate.  Mammals, crocodylians, & many turtles have a secondary palate, all other verts. lack this.  Salivary Glands = Present as multicellular, large glands only in Tetrapods, largest in amniotes. Comparative Digestive Anatomy

51.  Pharynx in non- amniotes also site or respiration (gills).  Esophagus is much longer in tetrapods than in non-tetrapods.  Crop = Distended region of the esophagus in birds for food storage Pharynx- Esophagus

52.  Stomach is ancestrally absent in vertebrates and its presence is a synapomorphy of gnathostomes. Secondarily lost in lungfishes and a few groups of teleosts.  Gizzard = Highly muscularized stomach body of archosaurs, stratified squamous (keratinized) epithelium. (Gastroliths = “stomach stones”) Stomach

53. Bird Digestive Tract

54.  No lg. & sm. distinction, just intestine.  Pyloric ceca = out-pocketings of ant. intestine for digestion & absorption in some Actinopterygii.  Spiral valve = Spiral flap in intestine, increases surface area. In all craniates except teleosts & tetrapods. Spiral valve ntestines with spiral valves usually shorter and wider.  Rectal gland = out-pocketing of posterior intestine; secretes excess salts in Chondrichthys. Non-Tetrapod (Fish) Intestine

55. Shark Digestive Tract

56.  Tetrapods have small & large intestines separated by the Ileocolic / Ileocecal valve.  Cecum = out-pocketing of anterior large intestine for fermentation of plant matter or other digestion. Synapomorphy of amniotes (ancestrally 1, birds have 2) Tetrapod Small & Large Intestine

57.  Cloaca = (sewer in Latin) ectodermal; intestine, reproductive system, & urinary system all empty into the cloaca.  Vent = external cloacal opening  Cloaca lost in therian mammals and Actinopterygiians. Separate, external anal and urogenital openings. Cloaca

58.  Liver usually large in chondrichthyans because it stores fats for buoyancy.  Gallbladder in gnathostomes but lost in many groups.  Pancreas distinct in gnathostomes (may be incorporated into liver in some teleosts & lungfishes as a hepatopancreas).  Pancreas may be single (as in humans and most verts.) or double when the two buds do not fuse. Associated Organs/Glands

59. salivary glands; spiral valve lost; lg. & sm. intest. (illeocecal sphincter) Craniates Myxini (hagfishes) lampreys Chondrichthys Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia true teeth; stomach stom. lost intestinal spiral valve; cloaca rectal gland cloaca lost cecum

60. sturgeons & paddlefishes gars bowfin (Amia calva) TELEOSTS reedfishes Class Actinopterygii Intestinal spiral valve lost cloaca lost (separate openings)

61. Amniota monotremes marsupials eutherians turtles lizards & snakes crocodilians birds crop; 2 large intestinal ceca gizzard cloaca lost large intestinal cecum

62. Subphylum Vertebrata Myxini (hagfishes) lampreys Chondrichthys Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia liver; pancreatic cells (diffuse in hagfishes & lampreys) gallbladder; distinct pancreas (from two developmental buds)

63. Vertebrate Digestive Tube Myxini & lampreys Chondrichthys Non-Teleost Actinopterygii oral cavity pharynxgill openings esophagus short stomachabsentpresent intestinesimple with spiral valve cloacapresent absent

64. Vertebrate Digestive Tube TeleostsLungfishesAmphibians oral cavity pharynxgill openings gill openings when larval esophagus short long stomachpresentabsentpresent intestinesimple, NO spiral valve simple with spiral valve NO spiral valve, small intestine large intestine cloacaabsentpresent

65. Vertebrate Digestive Tube MontremesTheriansTurtles oral cavity 2ary palate - oral & nasal 2ary palate - oral & nasal small 2ary palate - oral & nasal pharynxno openings (only Eustacean tube) no openings (only Eustacean tube) no openings (only Eustacean tube) esophagus long stomachpresent intestine NO spiral valve, small intestine large intestine (with 1 cecum) NO spiral valve, small intestine large intestine (with 1 cecum) NO spiral valve, small intestine large intestine (with 1 cecum) cloacapresentabsentpresent

66. Vertebrate Digestive Tube liz. & snakescrocodiliansbirds oral cavity large 2ary palate - oral & nasal oral cavity pharynxno openings (only Eustacean tube) esophagus long long with crop stomachpresentpresent with gizzard intestine NO spiral valve, small intestine large intestine (with 1 cecum) NO spiral valve, small intestine large intestine NO spiral valve, small intestine large intestine (with 2 ceca) cloacapresent

68. Cow Digestive System

69. Horse Digestive System

70. Human Digestive System