Labs Flashcards
Key things to look for in a salivary gland
Interlobular duct Lobules Nervous tissue Mucus acina Serous acina Interlobular striated duct
Interlobular duct histology
Long thin vessel, large lumen, no endothelial cell lining
Mucus acinus histology
Light staining due to absence of enzymes
Very peripheral nuclei
Lobular appearance
Serous acinus histology
Dark staining due to presence of zymogen granules containing digestive enzymes
More centralised nuclei
Interlobular striated duct histology
Kiwifruit slice
Large lumen, centralised nuclei
Adventitia is between a structure and:
Another structure
Serosa is between a structure and:
A body cavity
Connective tissue between oesophagus and trachea
Adventitia
Loose connective tissue
Allows expansion of oesophagus during swallowing
The outermost layer of the abdominal oesophagus is called the _______ _________ and is lined by __________ ____
Visceral peritoneum
Mesothelial cells
Histologically, how could you differentiate between the pharyngeal and gastric ends of the oesophagus?
Pharyngeal end contains skeletal muscle and therefore striations which stain darker around the edge of the tissue
Contraction of inner circular layer of muscularis externa allows:
Narrowing of lumen
Contraction of outer longitudinal layer of muscularis externa allows:
Tube shortening
Together with contraction of inner circular layer, peristalsis
Structures found in the lamina propria
Projections
Blood vessels
Layer of muscularis externa rarely seen
Innermost oblique layer rarely seen in histological sections
Feature of surface mucus epithelium
Goblet cells
Feature of parietal cells
Fried egg shape
Feature of chief cells
Bottom of gastric pit, stain dark due to presence of enzymes
Function of parietal cells
Secretes H+ and Cl-
Function of chief cells
Secretes pepsinogen
Layers of tissue in a histological section of stomach
Mucosa
- epithelium (including plicae circularis, villi, intestinal glands and microvilli brush border)
- lamina propria
- muscularis mucosae (doesn’t pick up stain)
Submucosa (contains blood vessels, can extend right up into plicae)
Muscularis externa
- inner circular
- myenteric nerve plexus
- outer longitudinal
The inner circular layer of the muscularis externa can look like it has many gaps because:
Dehydration from sectioning causes exaggeration of natural gaps. Also present in outer longitudinal but not as obvious
Paneth cells histology
Present in crypts
Stain dark and look similar to serous acina
Types of cells found in cryptal epithelium
Secretory cells
Enteroendocrine cells
Stem cells
Types of cells/structures found in villous core
Lacteal
Blood vessels
Lymphocytes
Peyers patches
Aggregates of lymphocytes near the colon end of small intestine. Proximal intestine also has some but they aren’t called Peyers patches
Nerve tissue is found in:
Muscularis mucosae and between the muscular layers in the externa
Exocrine pancreas histology
Stains dark due to zymogen granules
Makes up most of pancreas
Endocrine pancreas histology
Islets of Langerhans
Dispersed light staining areas
Area of pancreas with no stain picked up
Interlobular connective tissue - doesn’t stain
3 things to look for in exocrine pancreas
Pancreatic duct - large lumen, sometimes secretions can be seen, cuboidal cells
Vein - thin wall, blood cells can be seen inside
Arteriole - thicker wall
Organisation of hepatic lobule
Hexagonal lobule Central vein in middle Portal spaces at corners Hepatocytes and sinusoids radiate away from central vein Bile flows from CV to PS Blood flows from PS to CV
Hepatic artery histology
Small
Thick wall, small lumen
Bile duct histology
Smallish
Thin wall, large lumen
4th unseen portal space component
Lymphatics
Central vein structure
No smooth muscle
Only a little connective tissue for support
