In the lesson that follows, you will watch two videos of diabetic patients and create an initial model of what you think may be happening inside their bodies. 

After watching each of the videos below, answer the questions that follow. 

1. What do you think is the major difference between Type 1 and Type 2 diabetes? 
2. What evidence do you have that supports your answer to the previous question? 
3. What information do you currently have that helps you understand diabetes?  Note: please provide any prior knowledge you have about the disease, including (but not limited to) vocabulary words and explanations. If you have no prior knowledge about diabetes, then at least provide some information you learned from watching the videos.  
4. What more information do you need in order to fully understand what is happening to the patients in both videos? 

With your group members, you will create a drawing of the processes you think are occurring in a diabetic's body.  Your drawing can be created on paper or in a digital drawing platform, but either one should be uploaded (pictures are fine) once you have completed them. 

Your diagram/model should include the following components: 

1. Outline of a human body
2. Organs/organ systems involved in diabetes
3. Particular dysfunction within the system (body) - meaning you must somehow show WHAT is not being regulated properly in a diabetic's body. 
4. How dysfunction could lead to particular symptoms of a diabetic (think about what the patients in the video mentioned feeling or noticing about their bodies). 
5. Treatment of the dysfunction 
6. How a Type 1 and Type 2 diabetic will be DIFFERENT in terms of dysfunction and treatment (again, think about what was mentioned in videos). 

At this point, you may not have all of information needed to make a complete model, but you should be able to at least provide some background knowledge/explanations for how diabetes is an example of an imbalance in our body systems and disruption of homeostasis. 

In this lesson, you will assume the role of diagnosticians and complete urinalysis to determine if a patient has diabetes.  You can download the procedure here. 

This lesson was adapted from the Health and Science Pipeline Initiative: Medical Biology Lab 4, Homeostasis and Feedback. 

In this lesson, you will analyze data to determine what areas of your body account for the highest rates of glucose utilization.  You will also learn the different types of energy molecules the cells of your body use to perform their life sustaining functions. 

This lesson was adapted from a set of resources from Project Neuron, from the University of Illinois. 

You will need the following resources to complete this assignment.

• Human Body Outline
• Human Body Outline
• Metabolic Pathway Handout
• Metabolic Pathway Handout

What is a glucunculus?  A glucunculus is distorted drawing of the human body showing the relative size/proportion of the organs based on the amount of glucose that each organ uses.  The glununculus is based on a similar type of drawing, called a "homunculus" that shows the parts of the human body as relative to the amount of your brain that is devoted to that region.  A homunculus is shown below. 

These diagrams are meant to show that a large area of your brain's cerebral cortex is devoted to your hands (particularly your fingertips), mouth, nose, etc, due to our senses. 

With your partner, create a glucunulus on the human body outline your teacher gives you.  You should include the following components: heart, liver, brain, kidneys, fat, and muscle.  You can represent those organs/tissues in any way that you want, but it should be clear which organs you think are using more glucose (or are not using more glucose). 

Now that you have predicted what parts of your body might use more/less glucose, let's look at some data to determine how much energy each of your organs/tissues actually use. 

Step 1: Calculate energy consumption per organ/tissue.  

To understand how much energy each of your organs/tissues actually uses, we need to determine how large each organ actually is (what % of your total body weight). With this information, we can then calculate the ratio of % energy consumption to % of total body weight. 

Now that you have a better understanding of how much some of your organs and tissues use glucose (and their proportionate sizes), it's time to revise the glucunculus you created at the beginning of this lesson.  To do this, you first need to understand the ratio of % energy consumption to % of body weight by organ.  

Use the data you answered in the previous calculations to complete a simple calculation: % energy consumption/ % body weight.  You can fill out your calculations in the table below.  

After you have completed your calculations, go back to original glucunculus you created and in a NEW COLOR (or some other clearly identifiable representation), show the size of each organ based on its glucose utilization. DON'T WORRY!  YOUR DIAGRAM SHOULD LOOK DISTORTED!

In order for you to fully understand how the tissues of your body utilize molecules to gain energy, you need to complete the following assignment for homework.  You will need to visit: http://learn.genetics.utah.edu/content/metabolism/pathways/.  Feel free to click around the website if you want to find out more about how your body breaks down food to gain energy!

The glucunculus you created in your last diagram represented the use of glucose by different organs/tissues when the body is at rest.  But what would happen if you started exercising? Would the muscles change the amount of glucose they were using? What about studying hard for an exam - would the brain use more glucose then it did at rest?  How does your body regulate and respond when conditions change? The concept of homeostasis, or maintaining dynamic equilibrium, will be explored in this lesson. 

Have you ever wondered why you don't faint every time you stand up? Does it surprise you that even if you skip lunch you still can walk and talk? Explanations of those occurrences are quite complex.  For instance, the cells in your brain all are exceedingly sensitive to tiny changes in the levels of oxygen and sugar. Your blood pressure automatically rises when you stand up in order to maintain adequate oxygen flow to your brain.  Likewise, you can skip lunch because a declining level of sugar in your bloodstream triggers your liver to release sugar held in storage.  Your body must continuously make adjustments to create and maintain an environment for your brain to function.

These adjustments are made automatically and assure that conditions within your body remain within rather narrowly defined limits, a condition of balance called homeostasis (see Figure E5.1). Homeostasis is a fundamental characteristic of all living systems.  In animals, internal organs that are similar in function to those in humans help to maintain homeostasis.  Maintaining balance means life, and losing homeostatic balance for an extended period of time means death.  To maintain homeostasis, two things are required.  First, an organism must be able to sense when changes have occurred in the external and internal environment.  Second, it must be able to respond with appropriate adjustments.

For example, humans can monitor stimuli such as cold because we have sensory neurons in our skin that allow us to feel the outside temperature.  Once the messaging “cold” is received in the brain, our body can respond by changing blood flow.  Our heart rate may increase, and certain blood vessels may constrict. We do not consciously control this physiological process, it is involuntary. In other words, we do not decide what the body should do.  The body attempts to keep the brain, heart, and liver at a nearly constant temperature even if that means sacrificing fingers and toes.  The human body’s response to change is quite specific as well as involuntary.  For example, the body responds to cold temperate by diverting circulation to keep the most important internal organs warm.  This type of response is appropriate for the external conditions.  If the body becomes too hot, however, the circulatory system diverts blood flow away from the internal organs to protect them from damage caused by excess heat. These examples are rather dramatic, but the human body routinely senses and responds to thousands of small changes each day.  It is through many small, specific, automatic changes that living organisms sense and react to an environment that is ever changing and sometimes hostile.

This reading adapted from BSCS: A Human Approach                         

When doctors check a patient's "vital signs," one of the measurements that is sometimes taken is their blood glucose level.  The chart below should be used as a reference when answering the following questions. 

The graph below represents the blood glucose levels of a non-diabetic individual after eating.  Respond to the questions that follow to assess your understanding.  

When you created your glucunulus in your previous lesson, you analyzed data about glucose use by different tissues of the body.  After looking at this data, you were able to determine that the muscles use less glucose (per % body weight) than some of the other organs like the brain, kidneys, etc.  When a person is exercising, many tissues and systems in their body are at work, particularly their tissues.  Before analyzing a graph about blood glucose levels relative to exercise, answer the question below. 

The graph below represents a non-diabetic individual before, during and after exercise.  Use the graph to answer the questions below. 

Throughout this lesson, you have interacted with text and graphs to collect evidence that the body has a set point for blood glucose and actively works to maintain balance when levels fall outside of the "normal" range.  This idea of restoring balance is sometimes referred to as dynamic equilibrium, as dynamic refers to energetic or active - meaning that our body is maintaining stability for a set of internal conditions (blood glucose levels, temperature, pH balance, O₂/CO₂ levels, etc) by implementing lots of tiny changes.  

But if we can't see our individual cells and our tissues in action, then how do we know these minute changes are actually occurring? Use the diagrams below to help you answer this question. 

In this exploration, you and your group members will design an investigation to see if the human body maintains homeostasis as external conditions change.  In order to do this, you may choose one of the following conditions to test:

1. Internal temperature
2. Internal O₂/CO₂ balance (heart/breathing rate) 
3. Internal pH 

No matter which investigation your group chooses, everyone is collecting data to evaluate the following claim: 

Human body systems are regulated so that an internal stability is maintained as the external environment changes. 

All data collected will be graphed, so similarities should exist within the data so we can provide multiple lines of evidence to evaluate the claim (our body has multiple systems, so for this claim to be accepted/rejected, we should see a similar pattern in multiple investigations). 

If you are testing temperature, go to the next page (page 2). 

If you are testing pulse/breathing rate, skip to page 3. 

If you are testing pH, skip to page 4. 

ONCE YOU ARE APPROVED TO CONDUCT EXPERIMENT, EVERYONE SHOULD GO TO PAGE 5. 

For this investigation, you are testing whether or not the human body maintains a stable internal body temperature as external temperatures change.  To help you design your experiment, read the purpose and materials list below: 

Purpose:

The purpose of this investigation is to see if our internal temperature (core body temperature) remains constant when our body surface is exposed to changing external temperature. 

Materials:

• 2 temperature probes (1 flexible wire, 1 standard probe)
• Ice bath
• Timer
• Tape
• Towel

NOTE: A temperature probe placed on the inner elbow will give a reading that represents core body temperature. 

For this investigation, you are testing whether or not the human body maintains stability of two complex systems as external conditions change.  To help you design your experiment, read the purpose and materials list below: 

Purpose:

The purpose of this investigation is to see if two of our internal systems (circulatory and respiratory) maintain stability as external conditions change.  

Materials:

• 1 test subject
• Timer
• Diagnostician to measure breathing rate
• Diagnostician to measure pulse

NOTE: 

• Pulse can be taken at the wrist or via the carotid artery (underneath the jawline, by the lymph nodes).  The test subject may take their own pulse. 
• Breathing rate = 1 inhalation and 1 exhalation as one breath.  The test subject should NOT record their own breathing rate
• Measurements should be recorded for 30 seconds and multiplied by 2 to determine rate (per minute)

For this investigation, you are testing whether or not the human body maintains a stable pH as external conditions change.  To help you design your experiment, read the purpose and materials list below: 

Purpose:

The purpose of this investigation is to see if the pH of a living system maintains stability as external conditions change.  

Materials:

• 2 cups of distilled water (no more than 25 mL per cup)
• 2 cups of living homogenate (no more than 25 mL per cup)
• 1.0M solution of HCl (Hydrochloric Acid, a strong acid)
• 1.0M solution of NaOH (Sodium Hydroxide, a strong base)
• 2 droppers
• pH strips/pH meter 

NOTE: 

• The pH scale is a logarithmic scale which measures how acidic/basic a solution is and ranges from 0 to 14.  The pH of distilled water is about 7.0, and blood is about 7.35
• The stronger an acid is, the lower the number on the pH scale.  A very strong acid like HCl may register a pH as low as 1-3, depending on its concentration. 
• The stronger a base is, the higher the number on the pH scale.  A very strong acid like NaOH may register a pH as high as 11-13, depending on its concentration. 
• STRONG ACIDS AND BASES CAN CAUSE BURNS AND DAMAGE TISSUES - BE CAREFUL WHEN USING!

Once your teacher has approved your experimental design, you may conduct your experiment.  Remember that any QUANTITATIVE data should be recorded in a data table.  If you are unsure how to set up your data table, remember that every investigation is designed to demonstrate the stability/change of the system over time. In the case of the pH investigation, you are observing the stability/change of the system with the addition of drops of a solution. 

QUALITATIVE data should be recorded as observations below/beside the data table in your journal. 

Once you have recorded your data, you will graph it using Google Sheets (or other appropriate spreadsheet program) and upload it to Google Classroom (or CT-Stem website, depending on teacher preference). 

Remember the following when graphing;

T - does your title describe a cause/effect relationship between the variables you tested?

A - did you plot the correct variable on the correct axis? (http://mathbench.umd.edu/modules/visualization_graph/page02.htm) 

L - are both of your axes correctly labeled with units? 

K - did you provide a key? 

Even though you and your classmates completed different investigations, all of them should have provided you with experimental evidence to support the claim that living systems maintain a stable internal environment even as the external environment changes. 

A secondary claim could be made that living systems maintain stable internal conditions in response to changing external conditions. 

Look at the graphs below to help you answer the following questions. 

In this lesson, you will learn how the endocrine system and the brain work together to regulate multiple body systems and maintain homeostasis. 

Whatever investigation you and your group conducting in the previous lesson, you should have observed that the body does maintain homeostasis in several different systems. But how does that work? What part of your body controls this regulation? How do the systems of your body "talk" to each other to respond to changes in the external (and internal) environment?  How does your body "know" when the set point is not being met and conditions are out of balance? 

You and your classmates will be asked to perform a coordinated task without being able to talk directly to each other.  Your teacher will assign you into groups and give you a procedure to follow. 

As you saw in the activity you and your classmates participated in, what seems like a simple task can become quite complicated when multiple systems are involved.  So how does your body coordinate the actions of multiple systems to maintain an internal balance? The human body has many systems, and all of them have some sort of set point that has to be regulated. Some systems are regulated via chemical messengers, more commonly known as hormones.  Watch the video below to learn a bit about how two important hormones work to maintain blood glucose levels in our body. 

Now that you have a little bit better understanding of the endocrine system, think back to the "cracker" activity.  Answer the questions below to demonstrate your understanding of this complex system. 

In the previous video, the endocrine system works in a series of steps to regulate a system or particular condition (in this example, glucose levels in the bloodstream).  The numbered images below all represent different stages in the regulatory pathway, but they are not necessarily in order.  In the question that follows, you must put the diagrams in order from beginning to end.  

1.        ​2.      

3.        4.  

5.         6.

In this lesson, you will take what you have learned about maintaining balance and look specifically at how your body monitors and regulates the amount of glucose in your bloodstream.

The body normally keeps the blood glucose concentration between about 70 and 140 mg/dl. Two hormones (chemical messengers) play important roles in keeping the glucose concentration within this normal range. They are released from glands (specialized cells) into the bloodstream. The blood carries the hormones to other cells where they cause a specific response. The two hormones that regulate glucose in the body are insulin and glucagon, which are both secreted by special cells in the pancreas. The cells of the pancreas can sense small changes in blood glucose concentration. Because they are so sensitive, the cells of the pancreas can respond to changes before the blood glucose concentration can increase or decrease much. This process is occurring constantly to maintain stability within the system. 

The pancreas is constantly producing and releasing small amounts of insulin and glucagon, as they have opposite effects to control blood glucose levels. After a person eats a meal high in carbohydrates (which readily breaks down into glucose), the body detects this increase in blood glucose and triggers specific cells in the pancreas to release insulin.  Insulin acts on many other cells in the body so they can take up the glucose, lowering the overall concentration of glucose in the blood. Glucagon is released from the pancreas when the concentration of glucose in the blood is low. Glucagon stimulates cells of the liver to release stored glucose (called glycogen) into the blood, increasing the overall blood glucose concentration. It is the controlled release of both of these hormones that keeps the blood glucose concentration within the normal range.

This coordinated release of insulin and glucagon and is an example of a feedback system, in particular a negative feedback system.  Negative feedback systems work much like the thermostat in your house.  Your body has a set of internal conditions within a narrow range, called a set point.  When external conditions cause a change to those conditions (a stimulus) your body determines the appropriate action (response) to bring the conditions back to the set point.  Negative feedback loops are reminiscent of a "figure-8" diagram, because the stimulus can either be an increase or a decrease in the internal condition, so the response may be an increase or decrease to bring the system back to the set point.  Use the diagram below to help you understand this concept. 

Adapted from Diabetes Education in Tribal Schools “Health is Life Balance” curriculum.

Look at the following images and answer the questions below.

To demonstrate your understanding of glucose regulation in the human body, you and your group will create a model using whiteboards (or poster paper, if available) and cut outs of the following molecules and organs: 

Glucose

Glucose Transporters

Glucagon

Glucagon Receptors

Insulin 

Insulin Receptors

Glycogen

Liver

Pancreas

Muscles 

Cutouts for the molecules can be found here and the organs here.

Your model should show how all of these molecules move throughout the bloodstream and can cause an action inside cells.  You may wish to include other tissues/organs/systems in your model that are not listed above. 

Once you have completed the model of glucose regulation, your teacher will give you a scenario (there are multiple scenarios, so every group's model may look slightly different). Read through the scenario and adjust your model accordingly.  

In this lesson, you will use a NetLogo model to explore how insulin and glucagon regulate blood glucose levels throughout your body. 

The simulation you will be working with today is designed to model the role of the hormones insulin and glucagon play in regulating blood sugar levels. Before you begin the simulation, click on the “Info” tab to figure out how the interface functions.   You should read the following sections and record any notes below the model:

Run the model once without clicking any buttons (besides setup/go) or sliders.

Return to the INFO tab.  Follow the directions in the following sections and record your notes/answers below.

In this lesson, you will learn the different mechanisms behind Type 1 and Type 2 diabetes.  Once you have a clear understanding of how each type of diabetes works, you will revise your initial explanatory models to demonstrate a full understanding of the mechanism of the disease.