When food is ingested,
it travels along the digestive tract
where it's broken down
into its component nutrients
in order to be absorbed into the bloodstream.
One such nutrient is glucose,
a simple sugar.
Glucose gets absorbed by the stomach
and intestines and then enters the bloodstream.
It travels through the circulation
to all body cells.
Once absorbed into the bloodstream,
glucose circulates, causing the blood sugar
level to rise.
An increased level of blood sugars,
sends a signal to the pancreatic beta cells,
which respond by secreting the hormone insulin
into the circulation.
Insulin is necessary for glucose to reach
and be used by several important target
tissues throughout the body.
These include the liver, muscle,
an adipose tissue.
Insulin is necessary
to keep blood glucose levels
stable in the body.
Glucose enters the cell
through a process called "facilitated diffusion."