What Are Hormones?

Lesson Plan - Get It!

Audio:

The changes in your body caused by puberty are triggered by special chemical messengers, called, "hormones."

In the previous Related Lesson in our Endocrine System series, found in the right-hand sidebar, you learned how glands spread throughout the body produce and release these chemicals to communicate.

The endocrine system relies on hormones to carry out body functions like metabolism, development, and stress response. Notice how the hypothalamus produces a compound that travels to the pituitary gland, which produces another substance that moves to the adrenal gland. These substances are called, "hormones."

There are several important hormones that the body releases and uses on a daily basis. Males and females have different sex hormones that regulate puberty and sexual function. In women, estrogen is responsible for regulating menstruation and pregnancy. The male sex hormone is testosterone, which is responsible for the development of body and facial hair, a deeper voice, and muscle mass growth during adolescence.

• What happens when you get stressed out?

Most likely, your response is regulated by the hormone cortisol. This hormone helps keep your blood sugar and blood pressure in balance.

• Did you know that sleep is also regulated by hormones?

Melatonin is a hormone that responds to light and darkness in the environment to communicate to the body when to go to sleep. These levels fluctuate during the day, and are one reason we are sleepier during winter than summer! Recent research has concluded that melatonin can be negatively impacted by light from electronics, which is why we shouldn't use our phones in bed!

Insulin is another hormone that helps the body regulate blood sugar taken in from food. While it does play a role in diabetes, it also helps your body build necessary molecules. In the next Related Lesson, you will learn more about the role that insulin plays in the body.

All of these hormones are released from glands in the body into the blood stream. They travel through the bloodstream to the target organ or tissues, bonding with proteins found in the blood. Proteins help hormones bond with the cell membranes on the outside of the target cells. The cell membrane has many different components providing structure and the ability to communicate. For the purpose of this lesson, focus on the proteins in the membrane below, because they play a role in hormone communication:

Target cells in the body use the protein receptors, located in the membrane, to identify the hormone. Then, they collect the information communicated by the hormone and translate it into the cell. Protein receptors also help the body regulate the amount of each hormone in the body, because an imbalance in hormones can cause issues in the body.

There are many processes occurring in your body right now! Many of these processes are controlled by hormones moving through your blood towards cells and tissues. Sex hormones like estrogen and testosterone are triggering sexual development, while melatonin is helping you stay awake.

• How do you think the body adjusts the amount of hormone in the body if an imbalance occurs?

Discuss this question and what you have learned with a parent or teacher before moving on to the Got It? section to create a Venn diagram.