git ii esophagus and gastrointesinal tractanatomical-sciences.health.wits.ac.za/docs/git ii.pdf ·...
TRANSCRIPT
Dr Nadine Gravett School of Anatomical Sciences Room 2B10B [email protected]
Oral cavity
Mechanical breakdown
Formation of bolus
Oesophagus
Conduit from mouth to stomach
Stomach
Digestion
Temporary storage
Intestine
Digestion
Absorption
Colon
Temporary storage
Absorption
http://en.wikipedia.org/wiki/Human_gastrointestinal_tract
Lumen Muscularis
Externa
Submucosa
Serosa or Adventitia
Epithelium
Lamina Propria
Muscularis Mucosa
REMEMBER THE GENERAL 4 LAYERED PATTERN
Lumen
Muscularis
Externa
Submucosa
Mucosa
Adventitia
MUCOSA
Very folded
E: Stratified squamous non-keratinized
LP:
Nodular lymphatic tissue
Oesophageal cardiac glands
MM: Thick SINGLE layer
SUBMUCOSA
DICT
Deep oesophageal mucous glands
Diffuse and Nodular Lymphatic tissue
MUSCULARIS EXTERNA
Prox 1/3 → Skeletal
Middle 1/3 → Skeletal + Smooth
Distal 1/3 → Smooth
ADVENTITIA
Exception: Abdominal cavity → SEROSA
Lumen
Gland
Duct
BV
Adventitia
Myenteric Plexus
Submucosa
Mucosa
Muscularis Externa
IC
OL
Ross and Pawlina: Histology A Text and Atlas. 6th Edition (2011)
MUCOSA
Rugae and Mamillated Areas
Gastric Pits
Glands
E: Surface Mucous Cells
LP:
Areas around gastric pits and glands
Smooth muscle cells
MM: Thin
SUBMUCOSA
MUSCULARIS EXTERNA 3 Layers :
IO / MC / OL
Arrangement → FUNCTIONALLY important
SEROSA
Mucosa
Lumen
Lumen
Gastric Glands
Submucosa
Mucosa
MM
LP
Lymphatic Nodule
Surface
Mucous
Cells
LP LP
Gastric Glands
Surface Mucous Cells
Gastric
Pit
Gastric
Pit
Glands of the Gastric Mucosa
http://www.lab.anhb.uwa.edu.au/mb140/
CARDIAC GLANDS PYLORIC GLANDS
Highly branched, coiled tubular glands
Mucous secretion
Simple tubular glands Tortuous & occasionally branched
Mucous secretion Images: Ross and Pawlina: Histology A Text and Atlas. 6th Edition (2011)
Simple, branched tubular
Produce gastric juice
4 main cell types
Mucus neck cells
Chief cells
Parietal cells
Enteroendocrine cells
Ross and Pawlina: Histology A Text and Atlas. 6th Edition (2011)
Lumen Lumen
Muscularis
Externa
Submucosa
Mucosa
Serosa
THE SMALL INTESTINE IS HIGHLY FOLDED
INCREASE SA FOR ABSORPTION
WE SEE FOLDING OF THE:
o SUBMUCOSA
o MUCOSA
o APICAL SURFACE OF EPITHALIAL CELLS
VILLI
PLICAE CIRCULARES
MICROVILLI
VILLI PLICA CIRCULARES
MICROVILLI http://www.lab.anhb.uwa.edu.au/mb140/
MUCOSA
Extremely folded - Villi E: Simple Columnar Epithelium
with Striated/Microvilli Border
LP: Extends into Villi and surrounds intestinal glands
MM: Thin
Intestinal Glands / Crypts of Lieberkuhn Simple tubular gland
Opens at base of Villus
Lymphatic Nodules Peyer’s Patches
Lumen
Submucosa
LP
LP
LP
LP
MUCOSAL EPITHELIUM Simple Columnar Epithelium with
Microvilli
Maximizes SA for absorption
Goblet cells
Alkaline glycoprotein
Protection and lubrication
Enteroendocrine cells
Hormones and hormone-like substances
• CCK, Secretin , Motilin, GIP
Paneth cells
Lysosomal and bacteristatic enzymes
Immunological function
M Cells
Antigen transporting cells
SUBMUCOSA
Brunner’s Glands
Simple, branched tubular
Alkaline mucous
Neutralization of chyme
Ducts open into lumen of Intestinal Glands
MUSCULARIS EXTERNA
SEROSA/ADVENTITIA Mucosa
Submucosa
Muscularis
Externa Serosa
Lumen
IC
OL
Myenteric Plexus
Brunner’s Glands
SUBMUCOSA MUCOSA ME
Intestinal
Glands
Brunner’s Glands
Ducts
Brunner’s Glands
Secretory End-pieces
Meissner’s Plexus
Lumen
Serosa
Teniae coli
MUCOSA
Smooth surface
Intestinal glands
Epithelium: Columnar absorptive cells
Goblet cells
LP: Additional features Collagen table
Pericryptal fibroblast sheath
GALT
Lymphatic vessels
MM: Thin
SUBMUCOSA
ME - Tenaie Coli
Serosa/Adventitia
Lumen
GALT
LP
Intestinal
Glands
MM Submucosa
Mucosa
Histological structure of GIT
Pattern of GIT
Similarities & differences
Relate structure to function!!!