Layers of Alimentary Canal (GI tract) Flashcards
what are the layers of the GI tract?
mucosa
submucosa
muscularis externa
serosa/adventitia
what are the 3 layers of mucosa?
epithelium
lamina protpria
muscularis mucosae
where does the epithelium sit?
on a basal lamina
what is the lamina proprietor made of?
loose connective tissue
what is the muscularis mucosa made of?
a thin layer of smooth muscle
what is protective mucosa histologically?
non-keratinised stratified squamous epithelium
where would protective mucosa be found in the GI tract?
oral cavity
pharynx
oesophagus
anal canal
what is secretory mucosa histologically?
simple columnar epithelium with extensive tubular glands
where would you find secretary mucosa in the GI tract?
stomach
what is absorptive mucosa histologically?
simple columnar epithelium with villi and tubular glands
where in the GI tract would you find absorptive mucosa?
small intestine
what is protective and absorptive mucosa histologically?
simple columnar epithelium with tubular glands
where in the GI tract would you find mucosa that is both protective and absorptive?
large intestine
what is submucosa made of?
loose connective tissue
it has larger blood and lymphatic vessels
glands
submucosal plexus (enteric)
what is the muscularis external made of?
2 smooth muscle layers
inner circular layer
outer longitudinal layer
what is in the middle of the 2 smooth muscle layers of the muscularis external?
myenteric plexus
what is the serosa/adventitia?
an outer layer of connective tissue
what is serosa?
when the outer layer of connective tissue suspends the digestive tract
what is adventitia?
when the outer layer of connective tissues attaches to other organs
