Pancreas

Question 1

What does glucagon do, what’s it’s produced by in what organ part specifically and how is it released

Answer 1

Glucagon raises blood glucose and is produced by alpha cells of the tail of the pancreas in islets of Langerhans; it is released via marginalisation and exocytosis

Question 2

What chain polypeptide is glucagon and does it have a disulphide, is it flexible

Answer 2

Single chain polypeptide without disulphide and its flexible

Question 3

Does glucagon increase or decrease
Glycogenolysis
Glycogenesis
Gluconeogenesis
Ketogenisis
NE and E
GI tract hormones and Ach

Answer 3

Increases glycogenolysis so decreases glycongenosis
Increases gluconeogenesis by decreases fructose 2,6 biphosphate
Increases ketogenesis
Increases NE and E
Decreases GI tract hormones and Ach

Question 4

How does glucagon phosphorylate target cell enzymes

Answer 4

Binds to GPCR activating adenylate cyclase which increases cAMP which activates PKA

Question 5

What 2 aa stim glucagon secretion

Answer 5

Arginine and alanine

Question 6

What does insulin do and what’s it produced by in what

Answer 6

Movers blood glucose into cells and is produced by beta cells in the pancreas islets of langerhans

Question 7

What is insulin structure

Answer 7

2 polypeptide chains and 2 disulphide bridges inter chain and 1 intrachain with a short half life

Question 8

How do glucose move into beta cells and how does this lead to a chain resulting in marginaiton and exocytosis of insulin

Answer 8

Glucose moves into beta cells via FD through GLUT2 which causes depolarisation of ATP sensitive K+ channels which open Ca+ channels causing Ca+ influx which causes marginaiton and exocytosis of insulin

Question 9

What is the anabolic nature of insulin in muscle, liver, adipose

Answer 9

• muscle and liver have increased glycogenesis and decreased glycogenolysis and gluconeogenesis (more glycogen less glucose)
• adipose increases glycolysis so more glucose and decreases lipolysis and increase lipogenesis and esterfication of FA (more lipids less FA)
  -liver decreases aa breakdown and increases aa uptake and protein synthesis (less aa, more protein)

Question 10

Effects on Ach and GI tract hormones and NE and E on insulin

Answer 10

Ach and GI stim insulin while NE and E inihibit insulin

Question 11

How is insulin produced from mRNA

Answer 11

mRNA to preproinsulin which inserts into RER and single peptide at Nterminal is cleaved producing pro insulin
In ER endopeptidases remove C peptide between making mature insulin and c peptide
Insulin is stabilised/ storage/ secretion by Zn in Golgi appertus

Question 12

2 types of insulin

Answer 12

Pulsatile clears absorbed after a mean ANDREW
Protracted for cell growth, division, protein synthesis, DNA replication

Question 13

How does insulin cause glucose uptake from binding to a specific dimmer receptor

Answer 13

2 alpha and beta subunits of insulin bind to dimer and alpha folds around insulin moving beta chains together which activates TK and starts phosphorylation cascade leading to GLUT 4 expression (glucose transporter thats insulin dependent on striated muscle and adipose) - glucose uptake

Question 14

How does insulin inhibit ketoacid formation

Answer 14

Decrease fatty acid breakdown which decreases acetyl CoA in liver so inhibits ketoacid formation

Question 15

What are the exocrine and endocrine parts of the pancreas

Answer 15

Islets of langerhans are endocrine while acini and duct systems are exocrine

Question 16

What does alpha beta delta gamma and epsilon produce

Answer 16

Glucagon, insulin, somatostatin, pancreatic polypeptide for GI function, gherlin to increase appetite

Question 17

What’s re enteroendocrine cells

Answer 17

Found in gut wall and secrete gastrin and secretin as well as other peptide and amine hormones to regulate GI tract, pancreas and ANS activity