Ben's Bad Day Worksheet - Seattle Central Community College

Homeostasis Tutorial
(http://ats.doit.wisc.edu/biology/ap/ho/ho.htm)
Anatomy and Physiology
Do the tutorial about Ben’s problems with homeostasis http://ats.doit.wisc.edu/biology/ap/ho/ho.htm)
You will need to click on the green buttons associated with different times throughout the day. At each time, there is a new physiology
scenario. As you do the tutorial, answer the questions below.
Part I
1. 8 am: At 8 am, Ben’s blood pressure plummets. List the two body parts that respond to the problem with blood pressure in the
order that they respond (as described in the tutorial).
2. 8:30 am, Ben falls victim to a jacket thief.
a. What regulates shivering (control center)?
b. What is the effector?
3. 11:50 am What happens to Ben at 11:50 am? (Be specific)
a. Is this an example of positive or negative feedback?
4. 5 pm: Which two body parts are involved in the homeostasis challenge that occurs at 5 pm?
5. 8:30 pm: Ben is dehydrated. What are the three steps in the process used to regulate his plasma osmolarity?
6. 12 am: Ben’s glucose levels increase.
a. Which part of his body reacts first?
b. List ALL of the organs that respond next.
Part II
1. What two organ systems are major control centers for homeostasis in the human body?
2. Briefly compare and contrast how these two systems communicate with their effectors.
3. Page 5: Do the exercise on this page to order the sequence of signaling events (drag number 1 on to Step 1 on the
image (e.g. messenger released from the Nervous System). Repeat for each step in the signaling pathway. An
explanation appears for each step when you have made a correct selection. Please be patient as you drop the #’s
in the correct location.
4. Page 6: Fill in the Homeostasis Times.

Part III
Anatomy and Physiology
1. Draw a figure showing the roles of glucagon and insulin in regulating blood glucose levels.
2. Use the figure below to explain glucose regulation. Identify 1) set point mg/dl, 2) operating range, 3) regulated
variable, action of insulin on blood glucose levels, action of glucagon on blood glucose levels (see page 5 for help).
Label where the subject ate a high sugar meal. Label where the subject was fasted (in between meals). Explain
your reasoning.
Blood glucose
[90 - 100 mg/dl]
Time
3. Use the Internet to determine the 3 countries in the world have the highest incidence of diabetes. Write these
countries down. A good place to start is the World Health Organization. (http://www.who.int/en/)