7- Exocrine Glands

Question 1

What is the anatomical position, structure and function of the parotid glands?

Answer 1

• 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

Question 2

What stimulates salivary glands?

Answer 2

Question 3

What is parotitis and how is it treated?

Answer 3

• Inflammation of the parotid gland
• Blockage of ducts, viral infections (mumps) or tumours
• Antibiotics or surgery to drain when serious

EXTREMELY PAINFUL

Question 4

Which type of salivary gland are all of these?

Answer 4

Question 5

Why do you produce less saliva as you age?

Answer 5

More adipose tissue in salivary glands

Question 6

Where is most of the saliva produced?

Answer 6

Mainly submandibular (60%)

Then parotid (30%)

700 to 1.1L a day!!!!

Question 7

How do you tell the difference between intercalated ducts and striated (intralobular) ducts histologically?

Answer 7

Question 8

What order do the different ducts go in an exocrine gland?

Answer 8

Intercalated –> Striated (Intralobular) –> Interlobular –> Principal

Question 9

What type of gland is the submandibular gland?

Answer 9

Compound tubuloacinar

Question 10

What is the largest exocrine gland and what is it’s anatomical structure?

Answer 10

• Liver
• Right side of body with 4 lobes posteriorally
• Lots of connective tissue

Question 11

What is the blood supply to the liver?

Answer 11

Question 12

What is the flow of blood like when it reaches the liver?

Answer 12

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

Question 13

What is the portal triad?

Answer 13

Question 14

What is the liver lobule?

Answer 14

• Made up of six liver acinus
• Multinucleated hepatocytes

Question 15

What are the functions of hepatocytes?

Answer 15

• 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

Question 16

How is bile produced?

Answer 16

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

Question 17

Label this diagram of the liver.

Answer 17

Question 18

What are the main organelles in a hepatocyte?

Answer 18

• Lots of golgi
• Microvilli
• Lots of SER
• Lots of mitochondria

Question 19

What is a Kupffer cell?

Answer 19

• Histiocytes in other parts of the body
• Resident macrophages in sinusoids
• Remove aged erythrocytes and phagocytose bacteria
• Take over spleens function after splenectomy

Question 20

How does the liver remove harmful billirubin?

Answer 20

Haem passed from Kupffer cells passed to hepatocytes that conjugate billirubin to form glucaronic acid, which is secreted into bile

Question 21

What are stellate cells?

Answer 21

• 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

Question 22

What are dendritic cells?

Answer 22

• Antigen presenting cells
• Can activate stellate macrophages (Kupffer)

Question 23

Why is the liver classed as an endo and exocrine organ and how does it differ from the pancreas?

Answer 23

• Exo - Bile
• Endo - Albumina and Growth Factors

One cell unit makes both hepatocyte unlike in pancreas

Question 24

What are the functions of the liver?

Answer 24

• Detoxification
• Storage
• Anabolism
• Catabolism
• Endo/exocrine