Topic 8 - Glands (2) inc. liver Flashcards
How can you tell a duct is striated?
Nucleus will be in the middle, not near the basement membrane
Where in the parotid glands are blockages most likely to form, causing parotitis?
- in the striated duct because of neutrophils causing inflammation
Mention the substances secreted by these three glands: Parotid? Submandibular? Sublingual?
Parotid - almost totally serous (stains purple) Submandibular - mostly serous but more mucus than Parotid (stains pink) Sublingual - almost entirely mucous (stains light blue)
Control of salivary secretion is _______?
Neural
Which brings most blood to the liver? The hepatic artery or the hepatic portal vein?
- hepatic portal vein
What is a sinusoid?
A tube in the gap between two sinusoidal cells
Talk through the three types of capilliary vessels - continuous, fenestrated and sinusoid?
Continuous - very tightly packed endothelial layer, clefts between cells very small Fenestrated - little holes in the endothelium allow small molecules through Sinusoid - big intracellular gaps in endothelium and incomplete basement membrane
Label the parts of this portal triad system in the liver.
What are kupffer cells, found in the livers sinusoids?
- specialist macrophages
- trap and phagocytose any damaged or aged erythrocytes that were missed by the spleens work
What are stellate (Ito) cells?
- they sit between hepatocytes
- full of cytoplasmic vacuoles containing vitamin A (this is why cod liver oil is in tablets!) :0
- in cirrhosis they differentiate into myofibroblasts and deposit collagen causing liver fibrosis
What are the broad functions of the underrated organ known as the liver (what a legend)?
Storage - iron/Vit A,B,D,K/glycogen/copper
Production - proteins (albumen)/enzymes/lipid carrying proteins/amino acids
Destruction - Drugs/hormones/Haemaglobin (by bilirubin)/toxins/removal of RBCs (if spleen out)
Others - Bile production, hormones, growth factors, modification of hormones
What is liver produced bile used for?
- emulsification of fats
- assisting in Vit K absorption from small bowel
Broadly compare the glandular function of the liver and pancreas.
The liver is different to the pancreas because the same cell executes endocrine and exocrine function (hepatocyte - crazy cool versatile boiiii, also incrediiiibly regenerative)
