Histology Flashcards
what 4 layers make up the basis of the GI tract?
Mucosa
Submucosa
Muscularis externa
Serosa/Adventitia
what is the mucosa made up of?
Mucous membrane
Lamina propria
Muscularis mucosae
describe what the submucosa generally contains.
CT, larger blood and lymph vessels, glands and submucosal plexus
describe what the mucosa generally contains.
Mucous membrane containing epithelium and maybe gland cells
Lamina propria containing loose CT, capillaries, enteric neurons and lymphoid tissue
Muscularis mucosae which is a thin layer of smooth muscle
describe what the muscularis externa generally contains.
Circular muscle, longitudinal muscle with the myenteric plexus inbetween
describe what the serosa generally contains.
CT which either suspends or attaches the organ to other organs
what are the varying functions of the mucosa throughout the GIT?
Proctective, secretory, absorptive
what type of epithelium it the oral cavity, pharynx, oesophagus and anal canal lined with?
Non-keratinised stratified squamous
what type of epithelium lines the stomach?
simple columnar epithelium with extensive tubular glands
which type of epithelium lines the small intestine?
simple columnar epithelium with villi and tubular glands
which type of epithelium lines the large intestine?
simple columnar epithelium with tubular glands
what is the sulcus terminalis?
a v-shaped depression separating the anterior and posterior parts of the tongue
what are the differences in the histology of the anterior 2/3 and posterior 1/3 of the tongue?
Anterior is thick with papillae on the dorsal surface
Posterior is smooth and lacks papillae (except circumvallate) BUT has lots of lymphoid aggregates in the submucosa
what are the 4 types of papillae found on the tongue?
Filiform
Fungiform
Circumvallate
Foliate
describe structure of filiform papillae.
conical, elongated projections of CT covered with highly keratinised stratified squamous epithelium
Which papillae is the smallest and most frequent?
filiform
describe the structure of the fungiform papillae.
mushroom shaped projections scattered amongst the filiform papillae