eis 24: the endocrine system
Activity 1: Body Clock
Hormonal and nervous communication are both very important for our bodies, since they allow us to communicate different types of messages in different ways. For example:
Endocrine signalling is also helpful when we want to achieve cyclical responses in the body, such as circadian (daily) rhythms of sleep and hunger or monthly menstrual signalling. These types of cycles also involve input for your brain. This video helps to explain how our bodies keep track of time:
- Nervous communication is extremely fast and specific, which allows us to respond very quickly to the environment, carefully coordinate and quickly correct movements, and layer lots of nervous signals on top of each other to make advanced cognitive processes happen.
- Endocrine communication requires a lot less energy input to achieve simple responses, so it’s preferred for the types of processes that happen all of the time and can be achieved by this kind of control.
- Endocrine communication can be sustained over long periods of time, which is important for processes that need to happen over many days, months, or years, like growth and development.
- Endocrine communication travels throughout the whole body in the bloodstream and then acts on receptors that can be designed to do different things in different cells, which is ideal for causing widespread changes in the body, like during the fight-or-flight response or development.
Endocrine signalling is also helpful when we want to achieve cyclical responses in the body, such as circadian (daily) rhythms of sleep and hunger or monthly menstrual signalling. These types of cycles also involve input for your brain. This video helps to explain how our bodies keep track of time:
This video helps to explain further:
Basically, our brains keep track of time based on external inputs like light cues, and our brains then cause the release of hormones that then effect the changes. This activity will have you taking a closer look at your own circadian rhythms for sleeping and eating.
materials
- Paper and colored writing utensils OR digital drawing program
procedure
1. Over the course of a day, make note of when you wake up, when you feel hungry, when you eat/finish eating, and when you fall asleep.
2. Also make note of anything that you think may influence this timing, like when the sun came up, whether it was cloudy or sunny, whether you needed an alarm or caffeine to wake up, when it got dark, whether you were looking at electronics before bed, how late in the day you had caffeine, and when/if you exercised during the day. For food, yYou don’t have to keep track of all of these things, but keeping track of a few or more may help you to understand your circadian rhythm better.
3. For best results, keep track of these times over a period of a few days or even a few weeks to get a good average
4. Now, make a clock with the average times that you fell asleep and woke up. Label it with the following hormones:
You may wish to color-code these.
If you create something you love, we want to see it! If you have an Instagram and the permission of your relevant responsible adult, share with us @eons_learning, #CircadianRhythmEONS.
2. Also make note of anything that you think may influence this timing, like when the sun came up, whether it was cloudy or sunny, whether you needed an alarm or caffeine to wake up, when it got dark, whether you were looking at electronics before bed, how late in the day you had caffeine, and when/if you exercised during the day. For food, yYou don’t have to keep track of all of these things, but keeping track of a few or more may help you to understand your circadian rhythm better.
3. For best results, keep track of these times over a period of a few days or even a few weeks to get a good average
4. Now, make a clock with the average times that you fell asleep and woke up. Label it with the following hormones:
- Melatonin: activated at around the time you fall asleep
- Ghrelin: activated at around the time you start feeling hungry
- Cholecystokinin: activated at around the time you start feeling full
- Cortisol: released gradually starting a few hours before you wake up, and then goes back down again (and comes back up again when you feel long-term stress).
You may wish to color-code these.
If you create something you love, we want to see it! If you have an Instagram and the permission of your relevant responsible adult, share with us @eons_learning, #CircadianRhythmEONS.
Activity 2: Doing Background Research Using the Internet
Hormonal responses are to a certain extent hardwired by our biology, which can vary somewhat between people, and are to a certain extent affected by environmental changes, some of which we cause through our behavior.
For one of the hormones discussed either in this activity or in this lesson, do some research on reliable websites or other quality sources and discuss some of the ways that that response is different for different people because of biological, genetic, or medically significant differences between people. For that same hormone, do some research on reliable websites or other quality sources and discuss some of the ways that this response is affected by behavioral factors that we might be able to change. Then, put some thought into how our biology and our behaviors might affect each other and discuss whether you think it would be easy or difficult for a person to change either the hormonal response, their behaviors, or both.
This is not meant to be an overly exhaustive research project, but rather is designed to get you thinking about the back-and-forth relationship between our actions and our biology. It is also good for you to gain experience with conducting background research using the internet, including evaluating the reliability of different resources. If you’d like more guidance on how to do this, check out our “Navigating Online Information” tab in our resources section.
For one of the hormones discussed either in this activity or in this lesson, do some research on reliable websites or other quality sources and discuss some of the ways that that response is different for different people because of biological, genetic, or medically significant differences between people. For that same hormone, do some research on reliable websites or other quality sources and discuss some of the ways that this response is affected by behavioral factors that we might be able to change. Then, put some thought into how our biology and our behaviors might affect each other and discuss whether you think it would be easy or difficult for a person to change either the hormonal response, their behaviors, or both.
This is not meant to be an overly exhaustive research project, but rather is designed to get you thinking about the back-and-forth relationship between our actions and our biology. It is also good for you to gain experience with conducting background research using the internet, including evaluating the reliability of different resources. If you’d like more guidance on how to do this, check out our “Navigating Online Information” tab in our resources section.
Longitudinal Activity: Making A Model of The Human Body
Add these glands to your model of the body:
You may choose to label them somehow, but this is not required.
- Pancreas
- Thyroid gland
- Adrenal glands
- Pituitary gland
- Female or male reproductive system: You choose which.
You may choose to label them somehow, but this is not required.