7. Glands: Exocrine And Specialised Flashcards
What are parotid glands and what is the structure?
Secrete saliva
Have striated ducts, simple columnar epithelium but nuclei not at bottom of cell
Almost totally serous (can’t see lumen on slide)
White circles of adipose tissue
Where is the parotid gland located?
Just below the ear
What is the submandibular gland?
Mostly serous
More mucous
What are the 2 parts of submandibular glands?
Superficial and deep, separated by mylohyoid muscle
Where is the submandibular gland?
Bottom of jaw, below parotid gland
What is the sublingual gland?
Almost completely mucous
Mucous glands surrounded by serous glands
Where is the sublingual gland?
Under the tongue
Where do the salivary glands receive their stimuli from?
Parasympathetic and sympathetic ANS
Increases salivary secretion
Neural only
What impact does the parasympathetic ANS have on salivary glands?
Produces large volume of water saliva rich in enzymes
What impact does the sympathetic ANS have on salivary glands?
Produces small thick secretion of saliva, rich in mucus
Describe the hepatic portal vein
Links the capillary bed in the stomach and intestine where nutrients and toxins are absorbed to the liver sinusoids where nutrients and toxins leave
Describe a liver sinusoid
Larger than capillaries
Have large intercellular gaps to allow cells out
Have an incomplete basement membrane
Where are sinusoids found?
Spleen, bone marrow, liver, lymph nodes
What happens after blood moves into the hepatic portal venules?
Merges with hepatic arterioles and oxygen moves out into the hepatocytes
What is the portal triad made up of?
Branch of portal vein
Branch of hepatic artery
Branch of bile duct
All surrounded by hepatocytes
What are Kupffer cells?
Macrophages that move through liver sinusoids
What is the space of disse?
Contains serum like fluid and separates hepatocytes from sinusoidal lumen
What is the role of dendritic cells?
Pick up bacteria/fungi and present them to T cell to destroy
What do stellate cells do?
Pick up and store vitamin A
What do pit cells do?
Most active form of natural killer cell and kill tumour cells that enter sinusoids
What do Kupffer cells do?
Trap and phagocytose any damaged or aged erythrocytes that were missed by spleen
If spleen removed, cell take over removal of 120 day old (aged) erythrocytes
What causes liver fibrosis?
In liver cirrhosis, cells lose vitamin A storage capability and differentiate into myofibroblasts
Myofibroblasts synthesise and deposit collagen within perisinusoidal space
What does the liver store?
Iron
Lipid soluble vitamins
Glycogen
Copper
What is the role of liver in anabolism?
Major plasma proteins - albumin Enzymes Lipid carrier proteins Amino acid synthesis Haemopoeisis in fetus
What is the role of the liver in catabolism?
Detoxifies drugs, poisons and toxins
Hormones
Haemoglobin
What food hepatocytes contain?
Numerous mitochondria Lots of peroxisomes Free ribosomes RER and SER Golgi Glycogen deposits
