Histology Flashcards
Adventitia of gut may be lined by…
Serosa - layer of mesothelial cells resting on a basement membrane comprising the peritoneum
Oral cavity lined with…
Stratified squamous epithelium (robust so won’t tear away from sharp food)
Salivary glands lined by…
Secretory glandular epithelium
Sjorgen’s syndrome
Autoimmune disease where glandular epithelium are attacked by body lymphocytes resulting in no saliva (dry mouth)
Oesophagus lined by…
Squamous epithelium
Beneath it has submucosal glands which secrete mucous into lumen
Stomach lined by…
Gastric fundic mucosa (produce mucus)
Gastric body mucosa (contains parietal cells, chief cells
Gastric antral mucosa (less specialised and again produces mucus)
Small and large intestine lined by…
Glandular epithelium interspersed with endocrine cells
Layers of Bowel
Mucosa (glandular epithelium)
Submucosa (loose collagen connective tissue containing blood vessels)
Muscularis propria (2 layers, all smooth muscle, ganglion nerve cells sit between longitudinal and circular layers)
Serosal surface (mesothelial cells)
Interstitial cells of Cajal
Pacemaker cells of the muscular wall in the small intestine
Progenitors of gastrointestinal stromal tumours (GIST)
Crypts of the gut
U-shaped column like structures in the gut lining
Bottom of U - Stem cells divide keeping a copy of themselves at the bottom and the division creates a transit cell which is sent up to become a normal columnar epithelial cell lining the gut (apoptose eventually at top)
What is a crypt?
U-shaped “valley” between villi
What is MALT?
Mucosa-associated lymphoid tissue (found in mucosa of small intestine)
What are Giardia lamblia?
Bugs/parasites that sit on the mucosa of the small intestine giving people diarrhoea as absorption is harder
What occurs in the mucosa in coeliac’s disease?
Villus atrophy and crypt hyperplasia
Mucosa of colon?
Glandular, flat mucosa (no villi)
What comprises the liver epithelium?
Hepatocytes arranged in cords with intervening specialised blood vessels (sinusoids)
Portal tracts comprise…
Branches of portal vein, hepatic artery and the bile duct
And central veins
What is a classic lobule of the liver?
Area of the liver drained by one central hepatic venule (roughly hexagonal due to being surrounded by 6 portal tracts comprising bile duct, portal vein and hepatic artery branch)
What is an acinus of the liver
Area based around blood supply rather than blood drainage
Diamond shape (portal tracts at either end of the short axis and central veins at either end of the long axis)
What hepatocytes in the liver lobule are more richly supplied with oxygen?
Hepatocytes nearer the portal tracts (portal vein and hepatic artery) as blood from portal tracts travels through sinusoids to the central veins so hepatocytes closer to the central veins are more oxygen deprived
Features of hepatocytes in the liver
Polyhedral epithelial cells
Lots of mitochondria, large central spherical nuclei, prominent nucleoli,
3 important surfaces of hepatocyte
Sinusoidal (70%)
Canalicular (15%) (lies between hepatocyte and a bile canaliculus which drains bile secreted by hepatocyte into bile duct)
Intercellular (15%) (between adjacent hepatocytes)
What is contained within the Space of Disse?
Reticulin fibres and Ito cells (stem cell population in liver)
Sinusoids of liver structure
Fenestrated blood vessels lined with a thin vascular endothelium and no basement membrane
Contain phagocytic Kupffer cells (derived from blood monocytes)
