Histology Flashcards
what does stratified squamous mean?
many layers (for protection) of thin cells (good for diffusion)
what are the main layers of the GI tract?
mucosa
submucosa
muscularis externa
serosa
what is involved in the mucosa?
epithelium
lamina propria
muscularis mucosae
what is the Lamina Propria imvolve?
Loose connective tissue contains GALT (gut associated lymphoid tissue)
what does the submucosa involve?
loose connective tissue and Submucous Plexus
what does the Muscularis Externa involve?
inner circular layer and outer longitudinal layer
Myenteric Plexus
where exactly is the Myenteric PLexus located?
it is located in the muscularis externa, between the 2 muscle layers (circular and longitudinal)
what are the 4 types of Papillae?
vallate, fungiform, filiform, folliate
what is special about Filiform?
covers most of the dorsal surface and has NO taste buds
what are the major cells in the Gastric Glands and what is their functions?
Parietal cells- secrete HCl
Chief cells- secrete digestive enzymes
Stem cells- replenish cells
Enteroendocrine cells- produce hormones to control secretions and motility
what is different about the muscularis externa o the stomach?
has an Extra layer to aid churning
where are Crypts of Lieberkuhn located?
in the small intestine
what are the main cells of the small intestine?
enterocytes, goblet cells, paneth cells, enteroendocrine cells and stem cells
what do Paneth cells do?
keep bacterial flora in check via antibacterials
what is Brunner’s Glands?
glands located in Duodenum that secrete Alkaline mucus to protect from acidic chyme
what is the location of the tallest villi in small intestine?
Jejunum
where are Peyer’s Patches located?
Ileum and they are GALTs
they are in the Mucosa but extend into Submucosa
Does the large intestine mucosa have Crypts and Villi?
NO, it has crypts but NO villi
what do enterocytes in the large intestine do?
remove salt and water from faeces
what type of tissue is in large amounts in the appendix?
Lymphoid tissue
what shape are the lobules in the liver?
hexagonal lobules
what does the hepatic hexagonal lobules contain?
central vein and portal triad
what is involved in the portal triad?
portal vein, hepatic artery and bile duct
what is a sinusoid?
gaps between the Hepatocytes that blood flows through
they take blood from the portal vein and hepatic artery to the central vein
what are Kupffer Cells?
macrophages in the Sinusoids
what causes contraction of the Gallbladder?
Vagal nerve
Cholecystekinin from the Duodenum (when fatty food enters)
what are Acinar cells?
functional unit of the exocrine pancreas- store and secrete digestive enzymes
