7- Exocrine Glands Flashcards
What is the anatomical position, structure and function of the parotid glands?
- Bilateral, in front of the ears
- Purely serous acini
- Enclosed in tough fibrous capsule to limit swelling
- Secretes serous secretion that contain enzymes to digest and lubricate the bolus during swallowing
What stimulates salivary glands?
What is parotitis and how is it treated?
- Inflammation of the parotid gland
- Blockage of ducts, viral infections (mumps) or tumours
- Antibiotics or surgery to drain when serious
EXTREMELY PAINFUL
Which type of salivary gland are all of these?
Why do you produce less saliva as you age?
More adipose tissue in salivary glands
Where is most of the saliva produced?
Mainly submandibular (60%)
Then parotid (30%)
700 to 1.1L a day!!!!
How do you tell the difference between intercalated ducts and striated (intralobular) ducts histologically?
What order do the different ducts go in an exocrine gland?
Intercalated –> Striated (Intralobular) –> Interlobular –> Principal
What type of gland is the submandibular gland?
Compound tubuloacinar
What is the largest exocrine gland and what is it’s anatomical structure?
- Liver
- Right side of body with 4 lobes posteriorally
- Lots of connective tissue
What is the blood supply to the liver?
What is the flow of blood like when it reaches the liver?
Blood from the hepatic portal vein and hepatic artery, in the portal triad, enter hepatic sinusoids and travel through the liver acinus to the central vein
What is the portal triad?
What is the liver lobule?
- Made up of six liver acinus
- Multinucleated hepatocytes
What are the functions of hepatocytes?
- Protein synthesis and storage
- Carbohydrate metabolism and storage
- Fat metabolism and storage
- Cholesterol, bile salt and phospholipid metabolism
- Storage of vitamins and minerals
- Formation of bile
- Detoxification reactions
How is bile produced?
CYP450 enzymes in hepatocytes transform toxic molecules into less toxic molecules. They then transport them into bile canaliculi and then to the bile duct where they are combined with chemical modifiers and passed to gall bladder
Label this diagram of the liver.
What are the main organelles in a hepatocyte?
- Lots of golgi
- Microvilli
- Lots of SER
- Lots of mitochondria
What is a Kupffer cell?
- Histiocytes in other parts of the body
- Resident macrophages in sinusoids
- Remove aged erythrocytes and phagocytose bacteria
- Take over spleens function after splenectomy
How does the liver remove harmful billirubin?
Haem passed from Kupffer cells passed to hepatocytes that conjugate billirubin to form glucaronic acid, which is secreted into bile
What are stellate cells?
- Ito cells
- Store Vitamin A in lipid droplets
- Normally inactive but when there is liver damage they differentiate into myofibroblasts, causing cirrhosis
- Normal function unknown
What are dendritic cells?
- Antigen presenting cells
- Can activate stellate macrophages (Kupffer)
Why is the liver classed as an endo and exocrine organ and how does it differ from the pancreas?
- Exo - Bile
- Endo - Albumina and Growth Factors
One cell unit makes both hepatocyte unlike in pancreas
What are the functions of the liver?
- Detoxification
- Storage
- Anabolism
- Catabolism
- Endo/exocrine
