Lecture 13 - GI Flashcards
Mesentery
wall surrounding the tract and separating it from other tissues. Binds to the abdominal wall.
Serosa and its two layers
visceral inner layer and parietal outer layer. secretion between the two and aids in protection.
Muscularis externa
3 layers. outer longitudinal and inner circular muscle.
Mucosal layers
submucosa - may contain some lymphoid nodules
Mucosa - inner alyer of epithelium with microvilli
Small intestine unique features
interstinal villi and plica circularis
Interstinal villi
multiple juts into the lumen space
plica circularis
larger structure that juts into the lumen to increase surface area.
Colon unique features
invaginations of the wall (crypts of Lieberkuhn)
Auerbach’s plexus
connection to the nervous system that helps control the tract. In the muscluaris externa
Meissner’s plexus
also helps with nervous system control. In the submucosa
Mucosa
stratified squamous non-keratinized. muscularis mucosa (smooth muscle
esophagus’s muscularis externa
3 layers. upper skeletal, middle skeletal and smooth, lower smooth
esophagus’ mucosa
non-keratinized. esophageal glands in submucosa secrete mucous
esophago-gastric junction
change from stratified squamous to simple columnar with gastric pits
cardiac stomach
will have cardiac glands which are straight, tubular lined by mucous columnar cells. few parietal and chief cells.
Glands of body and fundus of stomach
glands are branched tubular which have a isthmus, neck, and base.
Isthmus cells of the glands of body and fundus of stomach
mucous cells and a few parietal cells
Neck cells of the glands of body and fundus of stomach
mucous cells and parietal cells