Endocrine Pancreas

Question 1

What is the normal range of blood glucose?

Answer 1

4.2-6.3mM 980-120mg/dl)

Question 2

What is the useful blood glucose reference for hypoglycaemia?

Answer 2

<3mM

Question 3

What are the 2 key endocrine hormones produced by the pancreas?

Answer 3

Insulin

Glucagon

Question 4

Where are pancreatic hormones produced?

Answer 4

Islets of Langerhans

Question 5

What are the four types of islets of langerhans cells?

Answer 5

Alpha
Beta
Delta
F

Question 6

What is the function of alpha cells?

Answer 6

Produce glucagon

Question 7

What is the function of beta cells?

Answer 7

Produce insulin

Question 8

What is the function of delta cells?

Answer 8

Produce somatostatin

Question 9

What is the function of F cells?

Answer 9

Produce pancreatic polypeptide

Question 10

What class of hormones does insulin belong to?

Answer 10

Peptide hormones

Question 11

What is the function of insulin?

Answer 11

Stimulates glucose uptake by cells

Question 12

What is the function of leptin?

Answer 12

Released by fat stores to depress feeding activity

Question 13

What is the absorptive state?

Answer 13

Ingested nutrients supply the energy needs of the body and excess is stored. Anabolic phase

Question 14

What is the post absorptive/fasted state?

Answer 14

Reliance on body stores to provide energy. Catabolic phase

Question 15

What is the significance of insulin as a hormone?

Answer 15

Only hormone which lowers blood glucose

Question 16

What type of channel is specific to beta cells?

Answer 16

Potassium ion channel that is sensitive to ATP within the cell

Question 17

What are some of the additional actions of insulin?

Answer 17

Increases glycogen synthesis in muscle and liver
Increases amino acid uptake into muscle, promoting protein synthesis
Has a permissive effect on growth hormone
Promotes K+ ion entry into cells
Inhibits the enzymes of gluconeogenesis in the liver

Question 18

What stimuli increase insulin release?

Answer 18

Increased blood glucose 
Increased amino acids in plasma 
Glucagon 
Vagal nerve activity 
Other hormones controlling GI secretion and motility

Question 19

What stimuli inhibit insulin release?

Answer 19

Low blood glucose
Somatostatin
Stress
Sympathetic alpha 2 effects

Question 20

What is the primary purpose of glucagon?

Answer 20

Raises blood glucose

Question 21

When is glucagon most active?

Answer 21

Post-absoprtive state

Question 22

What is the result of glucagon receptors being activated?

Answer 22

Increased glycogenolyis
Increased gluconeogenesis
Formation of ketones from fatty acids

Question 23

Describe glucagon receptors

Answer 23

G coupled proteins linked to adenylate cyclase/cAMP

Question 24

What stimulates glucagon secretion?

Answer 24

Blood glucose <5.6mM

Amino acids

Question 25

What are the stimuli that promote glucagon release?

Answer 25

``` Low blood glucose High amino acid Cortisol Stress Sympathetic innervation and epinephrine, beta2 effect ```

Question 26

What are the stimuli that inhibit glucagon release?

Answer 26

Glucose Free fatty acids Insulin Somatostatin

Question 27

What is the effect of increased parasympathetic (vagus) activity?

Answer 27

Increased insulin | Increased glucagon

Question 28

What is the effect of sympathetic activation?

Answer 28

Increased glucagon Increased epinephrine Inhibition of insulin

Question 29

What is the main action of somatostatin?

Answer 29

Inhibit activity in the GI tract

Question 30

How does somatostatin function?

Answer 30

Slow down absorption of nutrients to prevent exaggerated peaks in plasma concentrations

Question 31

What is the effect of exercise on blood glucose?

Answer 31

Entry of glucose into skeletal muscle increases | Increases insulin sensitivity of muscle

Question 32

What is the effect of starvation on blood glucose?

Answer 32

Adipose tissue breaks into free fatty acids | Liver converts excess FFAs to ketone bodies