On any given day, you may feel stressed, moody, happy, tired or thirsty. All of these feelings seem to move and change seamlessly—and they are all a result of your endocrine system.
Your endocrine system is made up of glands—for example, islets of Langerhans (within the pancreas)—that produce and secrete hormones and of organs—such as the liver—that respond to certain hormones. Hormones stimulate growth and affect your mood and emotions, including your response to stress. They also control your sleeping and eating patterns. Hormones are made in your endocrine glands. They are secreted in small amounts directly into your bloodstream and then travel to other organs where they cause different actions.
Hormones regulate your internal environment by working with every other system in your body to coordinate and direct the activities of your cells. There are nearly 30 different endocrine hormones—each with a specific function—that are released by the endocrine glands. All of these released hormones follow a similar pattern as they travel through your blood so they can affect specific cells.
Although the hormones work at the cellular level, the combined effect impacts major bodily functions such as growth, sleep, temperature, maturation and metabolism. For example, as you eat a meal, your circulating blood sugar (glucose) level increases. This increase in blood sugar is a signal for the pancreatic beta cell to secrete the hormone insulin. Insulin signals to muscle, liver and fat tissue to take more glucose from the blood and store it for future use. This signal allows the circulating blood sugar to stay within normal ranges. Finally, once blood sugar returns to a normal level, the beta cell stops releasing insulin.
So, the next time you are worried, tired or hungry, remember that your endocrine system is leading the way.
Jeffery S. Tessem, PhD. is an assistant professor of nutrition science in the nutrition, dietetics and food science department at Brigham Young University. His laboratory studies molecular mechanisms to expand functional beta cell mass as a treatment for diabetes.