Unlocking the Endocrine System - Lesson - www.TeachEngineering.org

Colorado: Science
- b. Analyze and interpret data to generate evidence that human systems are interdependent (Grade 5) [2009]
- c. Assess further scientific explanations regarding basic human body system functions (Grade 5) [2009]
International Technology and Engineering Educators Association: Technology
- F. A subsystem is a system that operates as a part of another system. (Grades 3 - 5) [2000]
- E. Technological advances have made it possible to create new devices, to repair or replace certain parts of the body, and to provide a means for mobility. (Grades 3 - 5) [2000]

Today we are going to talk about communication. Who can give me a definition of what communication is? (Possible answers: Communication involves talking to other people, conveying information between people, etc.). Great job! Thank you for thinking hard about that. Now, we have been talking a lot about astronauts and outer space, so let's think together about why communication would be important for astronauts. Does anyone have any ideas? (Possible answers: Astronauts need to be able to talk with each other, even when they are in their space suits, and the astronauts in the space shuttle need to be able to talk back and forth with mission control on Earth). Great answers! Now let's talk about one more group of people that need to be really good at communicating: engineers! Why do you think it is so important for engineers to be good communicators? Engineers must be able to explain their ideas so that other people can understand them.

How does this relate to the human body? Well, today we are going to learn about a body system that is all about communication! This system is called the endocrine system (write the word endocrine on the board). The endocrine system helps carry messages throughout your body, to tell your body what to do. You can think of it as a giant mail system.

Here is how it works: your body has many endocrine glands, which secrete hormones into your blood. The bloodstream carries the hormones to a specific place (an organ or a receptor) that is designed to receive them. Once the hormone gets to that specific place, it gives your body some special instructions. Some of these instructions tell your body to make more red blood cells, to make more white blood cells, to secrete acid to digest food, to absorb calcium, or even to make you not feel hungry any more. Hormones can also tell the cells in your body when to divide and grow.

So, if we compare this whole endocrine system to how mail gets delivered, the endocrine gland would be like someone who puts a letter in the mailbox, then the bloodstream (which would be like the mail carrier) carries the letter to exactly where it is supposed to go (to just the right new mailbox, which would be like an organ, or receptor). Then, when the person who receives the mail reads their letter, that is similar to your body receiving the hormone (at the organ or receptor) and then doing what the hormone (letter) suggests to do. Pretty neat, isn't it!

In a microgravity environment such as space, astronauts cannot easily send letters back to Earth to see how everything is going. However, astronauts need to be able to communicate with ground control on Earth to see if their body systems are being monitored correctly and even if the timing is right for their return to Earth. Engineers need to understand how to best communicate in return with the astronauts as well, and they work to design the technologies, including cameras, video equipment, satellite phones and monitoring equipment, to be able to communicate with the astronauts while they are so far from home.

Endocrine Gland:	A gland in the body which secretes hormones into the bloodstream.
Receptor:	A specific site on a cell designed to recognize and accept a specific hormone.
Hormone:	A chemical secreted by endocrine glands which carries instructions to the body.
Pituitary Gland:	Regulates other endocrine glands; secretes growth hormone.
Thyroid:	Regulates metabolic rate.
Thymus:	Assists in development of the immune system.
Adrenal Gland:	Regulates fluid and sodium balance; emergency warning system under stress.
Ovary:	Controls development of secondary sex characteristics and functioning of sex organs.
Testis:	Controls development of secondary sex characteristics and functioning of sex organs.
Pancreatic islets:	Helps regulate blood sugar.
Pineal gland:	Believed to regulate biorhythms and moods and stimulate the onset of puberty.

Today we learned about the endocrine system and how it helps the body communicate signals like when to grow or digest food. Who can tell me the four main parts of the endocrine system? (Answer: endocrine glands, hormones, receptor sites, bloodstream) How is the endocrine system like the mail system? Well, the endocrine gland sends a hormone message, like a letter, and the bloodstream mail carrier carries it to the receptor site, like a new mailbox. Lastly, the body reacts to the hormone message, as somebody might if they read the letter. It's all about communication!

Who remembers why communication is important to astronauts and engineers? That's right, astronauts and engineers have to communicate well with each other both on Earth and in outer space. Engineers also design the technologies that make communication in space and on Earth possible, including cell phones, digital video equipment and satellites.