How the body regulates blood sugar

Every cell in your body requires a constant supply of glucose for energy. Since glucose is transported around the body to those cells, blood sugar levels in the blood need to be regulated.  In fact, blood glucose needs to maintained within fairly strict limits because problems will result if those levels get too low (hypoglycaemia), or too high (hyperglycaemia).

The regulation of blood sugar level is a feedback mechanism – something that is common in your body, and largely under hormonal influence.

Over a 24 hour period, normal blood glucose levels show slight variations, with slight increases after meals, but this should drop again to a lower constant level.  Over night, or after fasting, a healthy individual will show only slight reductions in blood sugar levels.  So, how does the body regulate blood sugar?

Here is a diagram of the overall process:

glucoseregulation

Blood Sugar Levels Rise

If blood sugar levels increase (e.g. after a meal), the beta cells of the islets of Langerhans in the pancreas produce insulin.  The insulin has an effect on various organs of the body, increasing cell permeability to glucose and increasing enzyme activity in the cells allowing the glucose to be taken up and stored.

The liver and muscle tissue converts glucose to glycogen and stores it.  This helps reduce the levels of sugar in the blood.  In addition, the breakdown of fats in fat cells is inhibited, so that glucose will be used preferentially for energy.

Blood Sugar Levels Fall

The alpha cells in the islets of Langerhans of the pancreas product glucagon.  Glucagon is “antagonistic” to insulin, basically having the opposite effect on the organs of the body.   Glucagon increases the conversion of stored glycogen into glucose in the liver and muscles thereby increasing blood sugar levels.

Glucagon also increases the uptake of amino acids and glycerol into the liver so that more glucose can be synthesized.

The importance of glycogen as stored energy

Since all of the cells in your body require a continuous supply of energy, it is important that your body stores excess “energy” eaten during meals so that it can be used when food is less plentiful.  Excess glucose is converted to glycogen by the mechanisms we saw above.

Glycogen is stored in the liver and the muscles.  When your body is active, energy requirements increase and stored glycogen can be converted to glucose to be used as energy.  If stored glycogen levels get too low however, cortisol is secreted from the adrenal cortex, and this stimulates the conversion of proteins and fats into glucose so energy levels can be maintained.

NOTE: People who cannot regulate their blood sugar levels are diabetic.  Many require daily injections of insulin (although this depends on the type of diabetes).  Scientists have turned to recombinant DNA technology to manufacture enough insulin to supply the diabetic population, including some novel solutions like Humalog and Novolog.  It’s almost identical to human insulin but acts much more quickly.  If you are interested, you can read more about Humalog & Novolog.

About Andy

Andy writes for a number of health related sites but has always been fascinated by alternative medicine and home remedies. His deep interests in nature and the body's innate ability to heal itself (given the right condition) have lead him to a pivotal time in his life - and so, Holistic Home Fitness was born. While it's relatively new at the moment, Andy wants to build this site into a huge reference site for a more holistic approach to health and fitness.

Comments

  1. This article is really helpful, not just to science students but to everyone who wants to learn more about diabetis.

  2. Diana Roehl says:

    After being put on an insulin pump I gained 40 lbs in 5 months. My blood sugars were always erratic but through the years it has become worse and my endocrinologist has not been able to help me gain control.
    Almost every day my blood sugars drop below 70 and almost everyday they rise above 200 without any apparent reason.
    I have stopped eating after 6:00 p.m. and this seems to help with my fasting blood sugars but doesn’t seem to affect what happens during the day.
    I am a yoga teacher I practice yoga almost everyday. I watch my diet and am very careful with the carbohydrates that I ingest.
    I would love to get off insulin altogether other than that any suggestions?

  3. Hi Diana – I’m not a doctor either. Don’t know if you’ve heard about this but you might want to look into the connection between the eating of wheat and diabetes. Google “wheat belly.”