Glucose Homeostasis

Question 1

4 regulatory hormones to counteract hypoglycaemia?

Answer 1

Glucagon
Cortisol
Growth hormone
Catecholamines

Question 2

3 types of cells in the Islets of Langerhans?

Answer 2

Alpha cells -> glucagon
Beta cells -> insulin
Delta cells -> somatostatin

Question 3

5 effects of insulin?

Answer 3

Glycogenesis
Glycolsysis
Increased uptake of glucose into cells via GLUT-4 transporter
Increase in protein synthesis
Reduction in breakdown of fat

Question 4

3 effects of glucagon?

Answer 4

Lipolysis for gluconeogenesis
Amino acid transport into liver for gluconeogenesis
Hepatic glycogenolysis

Question 5

7 steps of glucokinase reaction for insulin secretion?

Answer 5

GLUT2 transports glucose into beta cells
Glucose converted into G6P by glucokinase (hexokinase IV)
ATP produced
K+ channels closed, K+ increases in cell
Membrane depolarisation opens calcium voltage gated channels
Ca2+ influx causes insulin secretion
C-peptide cleaved off pro insulin to form insulin

Question 6

GI incretin effect?

Answer 6

Insulin levels increase more with oral rather than intravenous glucose due to incretins from gut

Question 7

Glucagon-like-peptide 1 (GLP-1)?

Answer 7

Secreted by L-cells in gut
Stimulate insulin release and inhibit glucagon
Gives feeling of satiety
Short half life from degredation by DPP-4