Regulation Of Blood Glucose Levels-Easy Notes

Three main factors are involved in the regulation of blood glucose levels:

1.Regulation by Hormones

2.Regulation in Fasting & Fed state

3.Regulation by Renal Mechanism.

I.REGULATION BY HORMONES:

--Concentration of glucose level in the blood is mainly maintained by the Liver.

--Liver can either release glucose into the blood or take-up glucose from blood.

--This release & take-up is mainly regulated by hormones.

-- Mainly there are two type of hormones 

    1.Hypoglycemic hormones - Insulin

    2.Hyperglycemic hormones - Glucagon,Epinephrine,Cortisol,Growth Hormone,ACTH,Thyroxine.

HYPOGLYCEMIC HORMONE - INSULIN

--Insulin is called hypoglycemic because it decreases the blood glucose level.

--It is released by the beta cells of islet cells of langerhans of Pancreas

--Insulin causes hypoglycemic effect in various ways - they are 

HYPERGLYCEMIC HORMONES -

--Glucagon, Epinephrine, Cortisol, Growth Hormone, ACTH are all called as hyperglycemic hormones because they increase the blood glucose level in the blood.

--In response to hypoglycemia these hormones are released into the blood which have an opposite effect to that of insulin.

II.REGULATION INFASTING & FED STATE

--In Fasting State

 --Blood glucose concentration decreases and hyperglycemic hormones like glucagon, epinephrine, cortisol, thyroxine are released to increase the glucose level in the blood.

 --Initially , in the early stages (i.e. at 2-5 hours after meal ) blood glucose level is maintained by glycogenolysis and after 5 hours gluconeogenesis helps in maintaining the blood glucose level.

In Fed State-

    -- In Fed state i.e. after a meal when the concentration of glucose is high , insulin is secreted and it helps in the absorption of glucose by all extrahepatic tissues except brain,

    -- It also promotes conversion of glucose to the storage form i.e. glycogen and fat.

III.REGULATION BY RENAL MECHANISM

--Renal Tubule help in maintaining blood glucose level by absorbing extra glucose from the filtrate in hypoglycemic conditions and by inhibiting absorption in  hyperglycemic conditions.

-- But when the blood glucose concentration is >180 mg/dl , renal tubules will not absorb extra amount of glucose from the glomerular filtrate and as a result the extra amount of glucose appears in urine causing glucosuria.