Exocrine and specialised glands

Question 1

Order of salivary glands from totally serous to totally mucous

Answer 1

Parotid, submandibular, sublingual

Question 2

Parotid gland key points (5 things)

Answer 2

• Acinar gland that occurs in pairs
• Situated below and in front of each ear
• Compound gland
• Enzyme secretion stored in zymogen granules
• Blockage can give rise to parotitis

Question 3

Submandibular gland key points (5 things)

Answer 3

• Mixed gland
• Tubuloacinar
• Lie just below mandible on either side of neck
• Release secretions into floor of mouth
• Via duct openings on each side of frenulum of tongue

Question 4

Control of saliva secretion neuronally in autonomic NS (2 things)

Answer 4

• Parasympathetic: serous
• Sympathetic: mucous

Question 5

What direction does bile flow in the liver?

Answer 5

Opposite to blood flow in a countercurrent system

Question 6

Where do the hepatic artery and HPV come together?

Answer 6

Sinusoid

Question 7

Where are fenestrated capillaries found (4 things)?

Answer 7

• Pituitary
• Small intestine
• Kidneys
• Some endocrine glands

Question 8

Sinusoid capillaries key points (3 things)

Answer 8

• Incomplete basement membrane
• Large intercellular gaps between cells
• Found in spleen, bone marrow, liver & lymph nodes

Question 9

Are hepatocytes multinucleated?

Answer 9

Sometimes- bi or tri

Question 10

Progression of canaliculi to hepatic ducts (5 things)

Answer 10

• Canaliculi
• Interlobular tributaries
• Periportal bile ductules
• Bile ducts
• Left and right hepatic ducts

Question 11

What are pit cells and what do they do (2 things)?

Answer 11

• Most active form of natural killer cells
• Kill tumour cells that enter sinusoids

Question 12

Küpffer cells key points (5 things)

Answer 12

• Specialised macrophages
• Patrol sinusoids
• Migrate into liver tissue at sites of inflammation and damage
• Recycle old RBCs and ingest pathogens
• Important after splenectomy

Question 13

Stellate (Ito) cells key points- e.g. liver cirrhosis (5 things)

Answer 13

• Full of cytoplasmic vacuoles containing vitamin A
• Liver cirrhosis causes loss of vitamin A storage ability
• Causes differentiation into myofibroblasts
• Synthesise & deposit collagen into perisinusoidal space
• Results in liver fibrosis

Question 14

What do hepatocytes contain more of compared to other cells (6 things)?

Answer 14

• Mitochondria
• Peroxisomes
• Ribosomes
• ER
• Golgi complexes
• Glycogen deposits

Question 15

Low to mild liver regeneration <50% (2 things)

Answer 15

• Viral infections & occasional alcohol use
• 7-8 days

Question 16

Mild to medium liver regeneration- up to 70% (2 things)

Answer 16

• Transplant, drug toxicity or heavy alcohol use
• 30-40 days

Question 17

Medium to severe liver regeneration- >70% (2 things)

Answer 17

• Chronic liver failure, cirrhosis, chronic alcohol misuse, suicide attempts
• Never

Question 18

How is liver regeneration achieved (5 things)?

Answer 18

• Autocrine signalling
• Gap junction signalling
• Paracrine signalling
• Endocrine signalling
• Intracrine signalling

Question 19

Functions of liver (7 things)

Answer 19

• Storage
• Anabolism
• Catabolism
• Bile production
• Blood filtering
• Endocrine
• Modification of hormones for excretion

Question 20

How is liver different to pancreas?

Answer 20

The same cell executes both endocrine and exocrine functions- the hepatocyte

Question 21

Functions of bile (2 things)

Answer 21

• Emulsifies fats
• Assists in vitamin K absorption from small intestine