Comparative Anatomy of Digestive Tract: Mucosal Tissue Variations across Tract
Detailed comparison of mucosal structures in esophagus, stomach, small intestine, and large intestine. Understanding the diversity and similarities in digestive tract tissues.
Comparative Anatomy of Digestive Tract: Mucosal Tissue Variations across Tract
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Digestive tract
Dark C Taste pore Light C Taste bud
circumvallated papillae(HE) filiform and fungiform papillae(HE)
Foliate papillae-taste bud (HE) Tongue foliate papillae(HE) Taste pore
● mucous membrane of tongue • Lingual papillae: filiform, fungiform & circumvallated. • Tast bud: dark C, light C & basal C.
General structure of the wall 1.mucosa: • epithelium: • Lamina propria: • Muscularis mucosa: 2.submucosa: 3.Muscularis externa: 4.adventitia:
4sub mucosa 1Epi. 2lamina propria 4esophageal glands 3 muscula ris mucosa 5inner circular M 6 adven titia 5outer longi tudinal M Esophagus (HE)
epithelium Esophageal gland Esophagus
Esophagus 1.mucosa: ● Epi.: stratified squamous. Non-keratinized ● lamina propria: CT. ● muscularis mucosa: boudles of SMC.longitudinal 2.sbumucosa: esophageal glands, mucous. 3.muscularis: inner circular, outer longitudinal 4.adventitia:fibrosa. • upper1/3:skeletal M. • middle: mixed. • Lower1/3: smooth M.
Stomach • mucosa: • Simple columnar Epi.:surface mucous cell • Lamina propria:gastric pit, gastric glands • Muscularis mucosa: inner circular, outer longitudinal. • submucosa: LCT. • muscularis:inner oblique, middle circular, outer longitudinal. • Adventitia: serosa.
fundic glands location:lamina propria compositions: 1.Chief C 2.Parietal C 3.Neck mucous C 4.Endocrine C 5.Stem C
Secretory granule nucleus rER Chief cells • LM: • Lower columnar; • basophilic; • Nucleus located in the lower parts. • Secretory granules. • EM: • Gol , Apical of the nucleus; • mit. & rER ,basal part of cytoplasm; • Secretory granules, apical ofcytoplasm. • Function :pepsinogen
microvilli nucleus Introcellular canaliculi Mitochondria Parietal cells • LM: • C large,cone-shapedor round. • acidophilic. • Nucleus is round ,centrical. • EM • Introcellular secretory canaliculi & microvilli. • Tubulovesicular system. • Mit. are abundant. • functions: • Hcl & intrinsic factor.
small intestine ileum jejunum duodenum
1 striated border Central lacteal 1 absorbtive C 2 goblet C SMC Cap. 5 stem C Intestinal gland 3 Paneth C 4 endocrine C
villi folds submucosa muscularis adventitia Intestinal villi
microvilli (striated border)
Small intestine • mucosa: • Epi.: simple columnar, absorbtive C + gobletC. • Lamina propria: small intestinal gland ,central lacteal. • Muscularis mucosa: inner circular, outer longitudinal. villi: the finger-like processes composed of epithelium layer and lamina propria protruding into the lumen .
submucosa • The duodenal gland, mucosa. Circular folds: mucosa&submucosa protruding into the lumen . Appears as processes. • muscularis: inner circular,outer longitudinal . • adventitia: serosa.
@@@@@small intestinal gland • AbsorbtiveC • GobletC • EndocrineC • StemC • Paneth C • LM: the base of gland. arranged in groups of 3-5 cells . in the apex, coarse acidophilic granules. • EM: protein-secreting cell. • functions: produce lysozyme.
Epi. Large intestinal gland (goblet C) Lamina propria Muscularis mucosa Mucosa of large intestine(HE)
Large intestine • mucosa: no villi ,no circular folds. • Simple columnar Epi.: abundant goblet C. • Lamina propria: large intestinal glands, no paneth C. • Muscularis mucosa:
appendix • No villi, • intestinal gland • Is scanty. • Lamina propria: • abundant LT. • Serosa
The comparisons between mucosa of variant digestive tract (1) Small intestine Large intestine esophagus stomach Gastric pit surface villus Simple columnar Striated border Goblet C Simple Columnar Goblet C abundant Striated squamous Simple columnar Epi.
The comparisons between mucosa of variant digestive tract (2) • Fundic gland of stomach: chief , parietal, neck mucous , endocrine, stem C. • Small intestinal gland: absorbtive, goblet, paneth, endocrine, stem C. • Large intestinal gland: absorbtive, goblet, endocrine, stem C.
Key points • Structure characteristics of variant digestive tract. The similar and the different. • Esp, the variance of tunica mucosa. Such as , the villi and the glands.