Endocrine Pancreas

Question 1

What is the function of the endocrine pancreas?

Answer 1

Regulation of metablism

Question 2

What are islets of Langerhans?

Answer 2

Isolated clumps of cells

Surrounding a capillary

Question 3

What are the 3 types of islets of Langerhans and what do they secrete?

Answer 3

Alpha - glucagon
Beta - insulin (majority)
Delta - somatostatin

Question 4

Where do the hormones secured by islets of Langerhans go?

Answer 4

Into blood stream

Pass to liver via hepatic portal vein

Question 5

When is insulin released?

Answer 5

In response to increase plasma levels of glucose and amino acids

Question 6

Is insulin anabolic or catabolic?

Answer 6

Anabolic - builds glycogen

Question 7

Insulin is synthesised as pre prohormone, then converted to proinsulin. How is proinsulin converted to active insulin?

Answer 7

Cleave of c peptide, which makes the proinsulin inactive

Question 8

How is insulin deactivated? Where?

Answer 8

Cleavage of sulfur bonds

In liver

Question 9

What is the parasympathetic innervation via for the production of insulin?

Answer 9

Vagus nerve

Question 10

What happens to insulin during sympathetic activity and release of adrenaline?

Answer 10

Decreased production

Question 11

How long is the half life of insulin?

Answer 11

5/10 minutes

Question 12

Where does insulin bind on a cell? What affect does it have?

Answer 12

Receptors

Mobilises GLUT4 to cell membranes to allow glucose to leave cells

Question 13

Which tissues are insulin independent? How do they control glucose uptake?

Answer 13

Brain, liver, intestines, kidney, mammary glands

Different GLUT transporters

Question 14

What happens to the kidneys in diabetes mellitus?

Answer 14

Capacity for kidneys to absorb glucose is exceeded

Question 15

Cats are more prone to which type of diabetes?

Answer 15

Type II

Question 16

What is type 1 diabetes?

Answer 16

IDDM

Pancreas inflammation, hypersecretion of hormones.

Question 17

What is type 2 diabetes?

Answer 17

NIDDM

Normal insulin production, but cells resistant to its effect

Question 18

What does hyperglycaemia cause?

Answer 18

Polyuria
Polydypsia
Artificially high specific gravity due to glucosuria

Question 19

How can hyperglycaemia lead to metabolic acidosis?

Answer 19

Increased degradation of lipids
Increased fatty acids in plasma
Increased ketone production (some ketones are acidic)

Question 20

What is hypoglycaemia caused by? How is it treated? Is it common or rare in ruminants?

Answer 20

Insulin overdose or insulinoma (tumour of pancreatic B cells)
Treated by oral or IV glucose
Rare

Question 21

What is glucagon? Why is it released?

Answer 21

Hormone released in response to decreased levels of glucose and amino acids

Question 22

What does glucagon stimulate?

Answer 22

Gluconeogenesis

Glycogenolysis

Question 23

Glucagon is also synthesised as a prepro hormone, like insulin. Where is active glucagon deactivated and how?

Answer 23

Metabolism in liver and kidneys

Question 24

Where does glucagon bind to cells?

Answer 24

Target receptors

Question 25

What does the net effect of glucose plasma levels depend on?

Answer 25

Ratio of insulin to glucagon