Page 181 - BIOCHEMISTRY II

Regulations
1- Hormonal regulation

• Blood sugar levels are regulated by negative feedback in order to
keep the body in homeostasis. The levels of glucose in the blood
are monitored by the cells in the pancreas's Islets of Langerhans.

• If the blood glucose level falls to dangerous levels (as in very
heavy exercise or lack of food for extended periods), the alpha
cells of the pancreas release glucagon, a hormone which affects
liver cells. It acts to increase blood glucose levels. It converts
glycogen into glucose (this process is called glycogenolysis). The
glucose is released into the bloodstream, increasing blood sugar
levels.

• There are also several other causes for an increase in blood sugar

levels. Among them are the 'stress' hormones such as adrenaline,

several of the steroids, infections, trauma, and of course, the

ingestion of food. 185