1. Small Intestine, Large Intestine and anal cannel
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Small intestine
Large intestine
Small intestine

2. General Structure of the Digestive Tract
rat
General Structure of the Digestive Tract
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Epithelium with goblet cells and absorptive cells
Lamina propria
Muscularis
mucosa
Submucosa
externa
(tunica muscularis)
Serosa
central lacteal

3. Slide #37 (Ed 904-64b). Small intestine, donkey.
neuronal cell bodies of the submucosal (“Meissner’s) plexus
Mesothelium of serosa
tunica muscularis
the myenteric (“Auerbach’s) plexus located between the inner circular and outer longitudinal smooth muscle layers of the tunica muscularis
submucosal
(Brunner’s) glands
intestinal crypts (glands
of Lieberkuhn)
muscularis mucosa
lamina propria
muscularis mucosa
central lacteal

4. Slide #37 (Ed 904-64b). Small intestine, donkey.
Paneth cells
Intestinal absorptive cells
Simple columnar epithelium
Goblet cell
Paneth cell
brush” or “striated” border =
High density of non-branching microvilli of uniform length.
Microfilaments are the cytoskeleton component in microvilli

5. Slide #37 (Ed 904-64b). Small intestine, donkey
Paneth cells
Absorptive cells
Enteroendocrine
Cells (EC cells)
Mitotic figures

6. Enteroendocrine cells in fundic stomach, rabbit (toluidine blue)
To see the distribution of EC cells among glands
244
Enteroendocrine
cells
Chief cells
Parietal cell

7. 146 Duodenum, monkey Goblet and absorptive cells, Enteroendocrine cell
Crypts of Lieberkühn
Enteroendocrine cell
Muscularis mucosa
Lamina propria.
Submucosa
Submucosal Brunner's glands.

8. 152 Duodenum Absorptive cells Brunner’s glands Goblet cells
Paneth cell
Enteroendocrine cell
Intestinal villus

9. Slide #37 (Ed 904-64b). Small intestine, donkey.
Enteroendocrine
cells

10. DEMO SLIDE BOX 57 -­‐ Small intestine (ileum), dog.
Goblet cell
Intestinal
crypts (glands
Or Crypts of Lieberkuhn
Smooth
Muscle in
Intestinal
villus
lamina propria of the villi
central lacteals
Peyer’s patches

11. DEMO SLIDE BOX 57 -­‐ Small intestine (ileum), dog.
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Enteroendocrine cell

12. DEMO SLIDE BOX 225 (C-­‐H-­‐73). Small intestine (jejunum), dog.
Absorptive cells
epithelial
Modifications=
Brush border and goblet cells
central lacteal
Strips of
Muscularis
mucosa
lamina
subglandularis
muscularis mucosa
submucosa

13. DEMOSLIDE BOX 225 (C-­‐H-­‐73). Small intestine (jejunum), dog.
lamina
subglandularis
stratum granulosum
stratum compactum
muscularis mucosa
submucosa
Enteroendocrine
cells
Paneth cells
Absorptive cells
lamina
subglandularis

14. DEMOSLIDE BOX 225 (C-­‐H-­‐73). Small intestine (jejunum), dog.
Crypts of
Lieberkuhn
submucosa
tunica muscularis
lamina
subglandularis
muscularis mucosa
Submucosal
(“Meissner’s”)
Smooth muscle
cells
myenteric (“Auerbach’s”) plexuses
serosa.
Mesothelium of serosa

15. Slide #192 (Pf 5-­‐84d). Small intestine (jejunum), pig.
submucosa
Absorptive cells
lamina propria
tunica muscularis
muscularis mucosa

16. Slide #192 (Pf 5-­‐84d). Small intestine (jejunum), pig.
central lacteal
Brush border of absorptive cells
Intestinal absorptive cells
Simple columnar epithelium
Smooth muscle cells
of the muscularis mucosa
lamina propria
Goblet cell
Paneth cells
Enteroendocrine cells

17. Slide #89 (83 DF1) – Small intestine, puppy (dog).
Epithelium
Lamina propria
Muscularis
mucosa
Submucosa
tunica muscularis
Serosa

18. Slide #89 (83 DF1) – Small intestine, puppy (dog).
Lymph nodules
Intestinal crypts
(glands
Or Crypts
of Lieberkuhn
Small intestinal villi
central lacteal

19. Slide #89 (83 DF1) – Small intestine, puppy (dog).
Dividing cells
Epithelium
Lamina propria
Muscularis
mucosa (developing)
Submucosa with lymphoid cell infiltration
tunica muscularis
Serosa
myenteric
(“Auerbach’s”)
plexuses
Serosa
mesothelium

20. Compare luminal surfaces of the small and large intestines
small intestines
Villi
large intestines
NO Villi

21. DEMO SLIDE BOX 167 (C003-­‐H-­‐29) -­‐ Large intestine (cecum), dog.
villi are absent
Epithelium
Lamina propria
Muscularis
mucosa
Submucosa
tunica muscularis
Serosa
Smooth
muscle
Lymph nodules
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Peyer’s patches
mesothelium

22. DEMO SLIDE BOX 167 (C003-­‐H-­‐29) -­‐ Large intestine (cecum), dog.
villi are absent
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Epithelium
Lamina propria
Muscularis
mucosa
absorptive cells and goblet cells
Enteroendocrine cells

23. DEMO SLIDE BOX 61. Large intestine (colon), cat.
Epithelium
Lamina propria
Muscularis
mucosa (developing)
Submucosa with lymphoid cell infiltration
tunica muscularis
Serosa

24. DEMO SLIDE BOX 61. Large intestine (colon), cat.
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Epithelium
Lamina propria
Muscularis
mucosa
Submucosa
absorptive cells
goblet cells

25. DEMO SLIDE BOX 171 (E3-­‐H-­‐38). Large intestine (colon), horse.
the taenia coli; a gross thickening of the longitudinal layer of tunica muscularis in the horse.
taenia coli
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Lymph
nodules

27. DEMO SLIDE BOX 168 (C003-­‐H-­‐38) -­‐ Large intestine (colon), dog.
Intestinal crypts (glands
Or Crypts of Lieberkuhn
Epithelium with goblet cells and absorptive cells
Lamina propria
Muscularis
mucosa
Submucosa
externa
(tunica muscularis)
Serosa

28. DEMO SLIDE BOX 168 (C003-­‐H-­‐38) -­‐ Large intestine (colon), dog.
Enteroendocrine cells
Intestinal crypts (glands
Or Crypts of Lieberkuhn

29. Slide #43 (K9-­‐1). Anal region, dog.
the recto-­‐anal junction
and regional skin.
skin
rectum
goblet cells located
in the crypts
nonkeratinized stratified
squamous epithelium
rectum
regional skin
circumanal glands (perianal glands)
which can become neoplastic

30. Slide #43 (K9-­‐1). Anal region, dog.
keratinized stratified
squamous epithelium

31. Slide #43 (K9-­‐1). Anal region, dog
the circumanal glands (perianal glands) in this region
CCT
Walled off
with CCT parasite
external anal sphincter = bundles of skeletal muscle

32. DEMO SLIDE BOX 62-­‐ Rectum and anal canal, dog.
the circumanal (perianal) glands
skin
large invagination of the anal sac.
rectum
simple columnar epithelium

33. Again the simple columnar epithelium is missing
Again the simple columnar epithelium is missing. Note the approximate recto-­‐anal junction. At this junction, there is an abrupt change to nonkeratinized stratified squamous epithelium. Near the junction of nonkeratinized and keratinized stratified squamous epithelium, observe the large invagination of the anal sac. The inner circular layer of the tunica muscularis is somewhat thickened to form the internal anal sphincter. The skeletal muscle fibers are part of the external anal sphincter. The anal canal is continuous with the skin of the perineal region (note the change in epithelium to keratinized stratified squamous); see the circumanal (perianal) glands

34. DEMO SLIDE BOX 62-­‐ Rectum and anal canal, dog.
keratinized stratified squamous
the circumanal (perianal) glands
skeletal muscle fibers
are part of the
external anal sphincter
skin
nonkeratinized stratified
squamous epithelium
rectum
tunica muscularis (smooth muscle) is somewhat thickened to form
the internal anal sphincter.
skin
large invagination of the anal sac.
rectum

35. Large intestine or Colon, monkey

36. MUCOCUTANEOUS
JUNCTIONS

37. Slide 66: Recto-anal junction
External anal sphincter
Internal anal sphincter
Anus
Rectum

38. Slide 66 : Recto-anal junction
Keratinized stratified squamous epithelium
Hair follicles
Sebaceous glands
Gland ducts
Apocrine glands
Anus

39. Digestive tract distinguishing features human summary
Mucosa (epithelium, lamina propria, muscularis mucosa)
Submucosa (with submucosal plexuses)
Muscularis (Inner circular and outer longitudinal layers, with myenteric plexuses between them)
Adventitia/
Serosa
Esophagus
(upper, middle, lower)
Nonkeratinized stratified squamous epithelium; cardiac glands at lower end
Small esophageal glands (mainly mucous)
Both layers striated muscle in upper region; both layers smooth muscle in lower region; smooth and striated muscle fascicles mingled in middle region
Adventitia, except at lower end with serosa
Stomach
(cardia, fundus, body, pylorus)
Surface mucous cells, and gastric pits leading to gastric glands with parietal and chief cells, (in the fundus and body) or to mucous cardiac glands and pyloric glands
No distinguishing features
Three indistinct layers of smooth muscle (inner oblique, middle circular, and outer longitudinal)
Small intestine
(duodenum, jejunum, ileum)
Plicae circulares; villi, with enterocytes and goblet cells, and crypts/glands with Paneth cells and stem cells; Peyer patches in ileum
Duodenal (Brunner) glands (entirely mucous); possible extensions of Peyer patches in ileum
Mainly serosa
Large intestine
(cecum, colon, rectum)
Intestinal glands with goblet cells and absorptive cells
Outer longitudinal layer separated into three bands, the teniae colo
Mainly serosa, with adventitia at rectum
Anal canal
Stratified squamous epithelium; longitudinal anal columns
Venous sinuses
Inner circular layer thickened as internal sphincter
Adventitia