6C - Regulation Of Blood Glucose

Carbohydrate

Macromolecule that supplies most of our energy.

Glucose

Carbohydrate is broken down into this small and simple form.

Glycogen

Storage form of glucose. Can be stored in liver and muscle.

Glycogenesis

Process of creating glycogen from glucose.

Glycogenolysis

Process of breaking down glycogen into glucose.

Hyperglycaemia

Blood glucose levels above the normal range (>7.8mmol/L).

Hypoglycaemia

Blood glucose levels below the normal range (<4mmol/L).

Islet of Langerhans

Region of the pancreas that contains cells that secretes the key hormones of insulin and glucagon.

Alpha cells

Cells within the Islet of Langerhans that secretes glucagon.

Beta cells

Cells within the Islet of Langerhans that secretes insulin.

Glucagon

A hormone secreted by alpha cells of the pancreas when blood glucose levels are low.

Insulin

A hormone secreted by beta cells of the pancreas when blood glucose levels are high.

Total heat change

Formula: total heat change = heat in + metabolic heat - heat out.

Blood glucose regulation

Two hormones, insulin and glucagon, work to maintain the blood-glucose levels within a tolerance range of 4.0 - 7.8 mmol/L.

Insulin function

Produced by beta cells in the pancreas that bind to cell membranes to increase their uptake of glucose into the cell by facilitated diffusion.

Glucagon function

Produced by alpha cells in the pancreas and act on liver cells to convert glycogen to glucose which can then be returned to the bloodstream.

Blood glucose high

Insulin high = glucagon low.

Blood glucose low

Insulin low = glucagon high.

Stimulus-response loop

Outline the 5 key stages of the stimulus-response loop in blood glucose regulation.

Blood glucose fluctuation

Non-diabetics blood glucose levels fluctuate throughout the day.

After meal response

As glucose levels rise after a meal, insulin levels rise to try to remove the excess from the bloodstream.

Long time without eating

If there is too much time between meals, the BGLs may drop below the normal range.

Sample answer for blood glucose regulation

The absorbed glucose enters the bloodstream and BGLs increase quickly, leading to increased insulin production.

Beta cells response

Stimulated to release insulin into the blood which promotes glucose uptake by cells.

Alpha cells response

Stimulated to secrete glucagon which signals liver cells to break down glycogen into glucose.

Memory device for insulin

Insulin makes diabetics feel beta!

Key anatomy in blood glucose regulation

Identify structures that act as receptors and effectors.

Quick quiz topics

Blood glucose, insulin, glucagon, cells, liver/muscles.