Insulin and the Regulation of Glucose in the Blood

Control of blood glucose level by negative feedbach mechanism

When the blood glucose level goes up

·         Blood sugar (glucose) rises;

·         The pancreas detects the rise;

·         The pancreas pumps out insulin into the blood;

·         Insulin helps the uptake of glucose into muscles and other cells;

·         This causes the blood glucose level to fall to its normal set point; and

·         The pancreas detects the fall and switches off insulin production.

When the blood glucose level goes down

·         Blood sugar (glucose) drops;

·         The pancreas detects the drop in blood sugar;

·         The pancreas switches on the output of glucagon into the blood;

·         Glucagon signals the liver to break down glycogen into glucose;

·         The liver releases glucose into the bloodstream;

·         Blood glucose goes up to its normal set point; and

The pancreas detects the rise in blood sugar and switches off glucagon release

Questions? (Click "comments" and type your answers)

1. How does the body maintain its blood sugar level?
2. which hormone increases blood sugar level and which does decrease blood sugar level?
3. what is the function of the liver in the control of blood sugar level?

References:

• Learn. Genetics. Genetic Learning Science Center. (2011).Retrieved July 5, 2011, from http://learn.genetics.utah.edu/content/begin/cells/badcom/
• MyDr. Pancrease and insuline. (2003). Retrieved July 4, 2011, from http://www.mydr.com.au/gastrointestinal-health/pancreas-and-insulin

Anatomy and physiology

The endocrine Pancreas plays a major role in glucose homeostasis. The pancreas is positioned horizontally along the posterior abdominal wall, behind the stomach. The Pancreas is made up of two functionally different tissues; the exocrine pancreas, the major digestive gland of the body and the endocrine pancreas, the source of hormones (insulin, glucagon, and others).  The endocrine function of the pancreas is performed by clusters of cells called the islets of Langerhans and they represent only 2% of the total size of the pancreas.

Questions? (Click "comments" and type your answers)

1. Where is the pancrease located?
2. Describe the function of the pancrease?
3. Name the hormone that constitute the endocrine pancrease?

References:

• Learn. Genetics. Genetic Learning Science Center. (2011).Retrieved July 5, 2011, from http://learn.genetics.utah.edu/content/begin/cells/badcom/
• MyDr. Pancrease and insuline. (2003). Retrieved July 4, 2011, from http://www.mydr.com.au/gastrointestinal-health/pancreas-and-insulin

Glycemia regulation

Human blood contains glucose, and glucose is the only nutrient that can be utilized by some tissues such as the brain tissue to supply them with energy. However, more glucose may be absorbed than is immediately needed for energy, and in this case extra glucose will be absorbed in the liver and muscles in the form of glycogen , this process called glycogenesis, and also can be stored in the fat tissues in the form of triglycerides and  is referred to as lipogenesis. Blood glucose level is maintained around an average value (90mg/dl), an uncontrolled increase in blood sugar level can be dangerous, and a drop in the glucose level in the body can be harmful. Blood concentration level is regulated by negative feedback in order to keep the body in homeostasis.      

 Normal blood sugar regulation. After food enters the body (1), it is broken down and sugar enters the bloodstream (2). Sugar stimulates cells in the pancreas to release insulin (3). Insulin travels through th blood to other cells in the body and signals them to take up sugar (4).




Questions? (Click "comments" and type your answers)

1. where is the excess glucose stored  and in what form?
2. A blood sugar level above 140mg/dl is considered normal or abnormal?
3. What is the medical term used for high blood sugar and low blood sugar levels?

Reference:

• Life Science. Regulation of glycemia. (2000).
• Learn. Genetics. Genetic Learning Science Center. (2011).Retrieved July 5, 2011, from http://learn.genetics.utah.edu/content/begin/cells/badcom/
• MyDr. Pancrease and insuline. (2003). Retrieved July 4, 2011, from http://www.mydr.com.au/gastrointestinal-health/pancreas-and-insulin