Glucose homeostasis

Question 1

What is the importance of glucose in the CNS?

Answer 1

If blood glucose falls below 4-5mmol/L (hypoglycaemia), then cerebral function is increasingly impaired
If blood glucose <2mmol/ L = unconsciousness and death

Question 2

What does persistent hyperglycaemia result in?

Answer 2

Diabetes mellitus - can lead to damage in vessels etc - blindness, ischaemic heart disease

Question 3

What hormones bring blood glucose up again?

Answer 3

Glucagon
Cortisol(stress hormone)
Growth hormone
Catecholamines(secreted by adrenal glands in response to the stress)

Question 4

What hormone decreases blood glucose?

Answer 4

Insulin

Question 5

What kind of structure is the pancreas?

Answer 5

Gland, retroperitoneal structure, 15cm length/diametr

Question 6

Is the pancreas more involved in exo or endocrine secretion ?

Answer 6

EXO via duct to small intestine (98%)

2% ENDO - islets of langerhans

Question 7

Islet of langerhans

Answer 7

30% Alpha cells - glucagon
60% Beta cells - insulin
Delta cells - somatostatin (keeps other 2 balanced )

Question 8

What are gap junctions ?

Answer 8

Allow small molecules to pass between cells

Question 9

What are tight junctions

Answer 9

Create small intracellular spaces

Question 10

What communication is between the cells of islets of langerhans?

Answer 10

Paracrine

Question 11

What is the function of insulin?

Answer 11

Growth regulation

Reduces blood glucose

Question 12

What maintains foetal growth and development?

Answer 12

insulin growth factor