Sleep: A Balancing Act between our Internal and External Environments!

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Students will explain how external cues influence internal homeostatic processes which induce a daily condition known as sleep.

Big Idea

In the effort to minimize activities in the body and brain, the body uses external stimulants such as the sun's light to deactivate the brain to regulate daily sleep and wake patterns.


Lesson Background & Justification:

    Sleep is a condition of body and mind such as that which typically recurs for several hours every night, in which the nervous system is relatively inactive, the eyes closed, the postural muscles relaxed, and consciousness practically suspended. As a part of our natural Circadian Rhythms (24 hour cycles), sleep requires cooperation from the brain and internal chemical regulation that is mostly governed by external factors. In this lesson (2nd of a two part lesson) students become familiarized with the standard biochemical events that are cued by sunlight or lack thereof via exploration activities that specifically addresses how and why sleep occurs and how it sleeping demands differ in different age groups as a function of their relationship with biological activities such as glucose metabolism, memory, ability to remove toxic cellular waste and the concentration of growth hormone.   

Prerequisite Knowledge: It is recommended that students be familiar with the structure and function of a neuron, the concept of neurotransmission, the action potential mechanism , metabolic processing of glucose and circadian rhythm. 

Lesson Preparations:

 In the effort to prepare for this lesson, I make certain that I have the following items in place: 

a) A class set of ChemMatters: So Tired in The Morning article copies and poster sized post it notes. 

b) Student lab books.

Common Core and NGSS Standards:

SP2- Developing and Using Models.

SP7- Engaging in arguments using evidence. 

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.

Standards Rationale:

      Modeling is the process by which scientists represent ideas about the natural world to each other, and then collaboratively make changes to these representations over time in response to new evidence and understandings. It is intimately connected to other scientific processes (asking questions, communicating information, etc.) and improves students ability to recall scientific jargon through association. In the classroom, it is important that teachers engage students in modeling practices, to set the foundation of success in a lesson or instructional unit. In this lesson modeling is used in concert with other science practices in the classroom to promote students’ reasoning and understanding of core science idea presented (mechanisms of maintaining homeostasis of the nervous via sleep regulation in the body).


5 minutes

Section Sequence:

a) Ask rhetorically- Ever wonder how we slip into the sleep phase? How are we wide awake one minute and in the next minute instantaneously lose certain functions and become vulnerable to the world? Say, let's see this in action in the following video montage: 


b) Post video, ask students to provide a possible physiological explanation (based on the lab data from the previous lesson if needed) for our sometimes instantaneous and sometimes gradual transition into sleep.  Take several responses and record a bullet summary of their responses on the board. Ask if they think that their list applies to individuals of varying ages. That is, do they as teenagers require the same biological or physiological triggers as adults and/or infants? Encourage students to share out with the class and to provide supporting information/data if possible. 

Standards Covered:

SP7- Engaging in arguments using evidence. 


35 minutes

Section Primer:

        Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism's environment. They are found in most living things, including animals, plants and many tiny microbes and have been implicated in irregular mental behaviors in humans when some aspect of the cycle is off balance (eg. not having enough sleep). In this section of the lesson, students use a series of videos to formally define what a circadian rhythm is and the brain's responsibility in this important process. This section proceeds as follows:

Section Sequence:

      In this section of the lesson, my goal is to provide students with visuals that connect their foundation knowledge of neuron activity and behavior and sensory systems to develop an appreciation for the physiological processes needed to induce the state of sleep. This activity proceeds as follows:

a) Slide 2- Share with students that sleep is a complicated process with grand benefits and to understand how it works, we must address it via a scaffold approach. Continue to assert the directions and for students to develop their notes as it appears on the slide. That is, students should copy the outline that is provided. This has a an overarching question as a heading, and subtopic titles beneath them. Proceed with the display of the images and videos in the following order:

What is a circadian rhythm?

Video: Circadian Rhythm Video

What part of the brain is responsible for sleep? Why do we need sleep?

Video: Why Your Brain Needs Sleep

How is the brain physically altered during sleep?

Input and output of external and internal factors: Image/Schematic 1

Anatomy and neurotransmission changes while sleep: Image 2

What is Sleep Paralysis?

Video: What is Sleep Paralysis? Sleep Paralysis


After each video, request for students to summarize their notes and to share information that was novel to them. Instruct for them to paraphrase the information and/or to create analogies that would help a younger child to understand the information and verbally share it with the class. Provide clarification at students request or simply facilitate a discussion that prompts students to share unclear concepts or ideas presented in the videos.

For each image, jump start the conversation with students by asking if they comprehend the message(s) that are being conveyed. If not, encourage them to select verbiage or an item on the image or schematic that they feel comfortable with. Choose this as an entry point by requesting the student to articulate what they know about that point. With your finger on the image, guide students attention to the connecting factor, read and paraphrase the statement. Ask students to then rephrase your words and to articulate the connection between their entry point your clarified connection. Continue this process until they are able to start making connections on their own. 

Standards Covered: 

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.


40 minutes

Section Sequence:

      In this section of the lesson, my goal is to have students extract meaningful text from an article that explains why teenagers continuously have a sleep debt compared to adults. Reading and dissecting the article for cause and effect statements helps students to apply their knowledge of sleep neurophysiology to a text that was intended for their reading. This section proceeds as follows:  

a) Slide 3- Supply each student with a copy of the American Chemical Society's Article: So Tired in The Morning, markers and one large post it note paper per student pair. 

b) Read the directions for the activity as it appears on the slide and support for students as questions arise. 

c) Display student work and allow for them to share out verbally with the class what they discovered in the article.

Standards Covered:

SP2- Developing and Using Models.

SP7- Engaging in arguments using evidence. 

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis. 


20 minutes

Section Primer:

        Graffiti Boards or walls are a part of the classroom, usually a very large sheet of paper, a whiteboard or chalkboard, where students engage in a written discussion. The purpose of the Graffiti Board strategy is to help students “hear” each other’s ideas. Some benefits of this strategy are that it 1) can be implemented in 5-10 minutes, 2) provides a way for shy students to engage in a conversation, and 3) provides a record of students’ ideas and questions that can be referred to at other points during the lesson (or even later in the unit or year). In this section of the lesson, this strategy will be used to help students review what they know on the topic and provide me with a visual on what each class has a strong or favorable command of or weakness in. I proceed with this activity as follows:

Section Sequence:

a) Slide 3: Explain what a graffiti wall activity is to students and share that each class will make their own unique one to demonstrate or show off their knowledge of a very difficult concept: Sleep Physiology. 

b) Provide a large and blank sheet of paper (6-8 feet in length), tape it on the board or wall and allow students freely to record what they know about the content covered or illustrate a process that they were particularly fond of learning in the lesson. This graffiti wall product will avail trends in student competencies (via repeated representations of the same material) and deficiencies (via little to zero visibility of specific material). To an instructor's benefit, this data can be used to decide what is worthy of review for future homework assignments, formal assessment practice guides or future lessons. 

Standards Covered:

HS-LS1-3-Plan and conduct an investigation to provide evidence that feedback mechanisms maintain homeostasis.



    For homework, supply students with a sterile 15 ml conical tube and cap and instruct them to capture at minimum 3 ml of their saliva in the tube when they wake up in the morning. Inform them that their samples will be utilized in an investigation the following day and that is important their samples be untainted with toothpaste or any morning consumables. Further instruct them to cap their samples, label the tube with their names and to bring their samples to class with them the following day.