20070918胃肠道组织学

Pylorus gland
Fundic gland ：
Chief Parietal cell Mucous neck cell Enteroendocrine cell Gastric stem cell
chief cell：zymogenic cell
Location: predominate in the lower of gastric gland
parietal cell ：oxyntic cell
Location: mainly in the upper half of gastric gland
LM: round or pyramidal morphology and intensely eosinophilic cytoplasm EM: intracellular canaliculus and abundance of mitochondria Function: secreting HCl and intrinsic factor
(fibrosa or serosa)
TONGUE
Lower surface：smooth
mucous
Dorsal surface：irregular
Filiform papillae Fungiform papillae Circumvallate papillae
Taste bud
muscularis：mass of striated skeletal muscular
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Tunica submucosa
Tunica muscularis
skeletal in upper 1/3rd mixed in middle 1/3rd smooth in lower 1/3rd
Fibrosa
Epithelium (non keratinized stratified squamous)
Pylorus region
Secrete mucus and enzyme lysozyme G cells secret gastrin, D cells secret somatostatin
SMALL INTESTINE
consist of duodenum, jejunum and ileum the main site of food digestion, metabolite absorption, and endocretion
large intestine
junction of rectum and anus
APPENDIX
• an evagination of cecum with small, narrow and irregular lumen
• abundance lymphoid follicles in its wall
submucosa muscularis: smooth muscle
inner oblique, middle circular, outer longitudinal
serosa: mesothelium
STOMACH: Divisions
Fundus
Cardia Corpus
Pylorus
Cardiac region
Gland is often coiled and has a large lumen
Secrete mucus and lysozyme
Junction of esophagus and cardia
Glands have long pits and short coiling
Filiform papillae
Fungiform papillae
Foliate papillae
taste buds
ESOPHAGUS
stratified squamous
epithelium Tunica lamina propria mucosa muscularis mucosae
•Intestinal villi: out growths of the mucosa
(epitheliam plus lamina propria) into the lumen
•Plicae circulares: the semilunar or spiral
projection of mucosa and submucosa Function: increasing the area of contact between the intestinal surface and food.
constitute
solitary lymphoid nodule aggregated lymphoid nodule
M cell(microfold cell)
M cell
location: overlaying the lymphoid follicles of Peyer’s patches morphology: numerous membrane invaginations forming pit at their apical and lateral surfaces and intraepithelial lymphocytes are contained in it function：endocytose antigens and transport them to lymphoid cells, so that initiate immune responses
no Panthe cells
• The lamina propria is rich in lymphoid cells
and nodules Function: absorption of water and formation of the fecal mass plus production of mucus
plicae circulares
duodenum
jejunum
intestinal villi
Central lacteal
Mucous membrane
•Microcilli: cylindrical protrusion of the apical
cytoplasm and the cell membrane
Characteristics oБайду номын сангаас different small intestine：
(from duodenum to ileum)
Decreased plicae circulares Increased goblet cells in mucous Increased lymphoid tissue in lamina propria and submucous
Histology shows corpus & fundus to be the same = “fundic stomach”
surface mucous cell
gastric pit--surface epithelia extent into lamina propria
Cardiac gland lamina propria Fundic gland
Digestion & Nutrition
教学目标及基本要求 1. 掌握消化管的基本结构。 2. 了解口腔粘膜的结构。 3. 了解舌的结构和牙的结构。 4. 掌握消化管各段的结构特点及功能。 5. 了解消化管的免疫功能。 6. 了解消化管内分泌功能。
General structure of digestive tract
LM: small than parietal cell, basophilic cytoplasm
EM: have the characteristics of a protein synthesizing Function: secreting pepsinogen which activated in acidic environment into pepsin.
Gastric stem cell few in number, these cells can differentiate into mucous neck, parietal, chief and enteroendocrin cells
Enteroendocrine cell small, pale, few; granules are located basally for release into the lamina propria
• fewer and shorter intestinal glands compared with other section of large intestine
appendix
lymphoid tissue of the gastrointestinal tract
diffused lymphoid cells
STOMACH: Cell types
Mucous neck cells present in cluster or as single cells between parietal cells in the necks of gastric glands. parietal cell/oxyntic cell Chief/Peptic cell
submucosal nerve plexus
gland(only in esophagus and duodenum)
muscularis: inner circular, outer longitudinal
(skeletal or smooth muscular)
adventitia：thin loose connective tissue
duodenum
ileum
LARGE INTESTINE
• Consists of rectum, colon and appendix • Long intestine glands, no villi • Great abundance of goblet and absorptive cells,
Goblet cell: less in the duodenum and increase in numbers
the ileum is approached.
Paneth cell: in the basal portion of the gland, synthesize a
complex of protein and polysaccharide
Enteroendocrine cell: secret hormone
Undifferentiated cell: gastric stem cells
goblet cell
absorption cell paneth cell
goblet cell absorption cell paneth cell
Tunica submucosa with glands
ESOPHAGUS
Junction of esophagus and cardia
STOMACH
mucosa: epithelium, lamina propria, mucularis mucosae
gastric pit, gastric gland
Intestinal villus
absorption cell goblet cell
striated border (microvilli)
Intestine gland
Absorption cell: tall columnar cells with striated
border(microvilli)
mucosa
epithelia lining: (stratified squamous or simple culumnar)
lamina propria: LCT(vessel, nerve, gland, LT)
muscularis mucosa: thin smooth macular
submucosa