Human Body Regulation

By Accessible Science on Feb 07, 2014

Purpose:

This lesson plan teaches students who are blind or visually impaired how the human body self-regulates to maintain a stable internal environment despite changes in the external environment -- a process called homeostasis. Students will:

  • Understand how the human body regulates temperature and how a fever fights infection
  • Explore ways in which the human body self-regulates to maintain homeostasis

Background Information:  When Body Temperature Overheats

  • Sweating leads to dehydration. When you sweat a lot, you lose water and need to drink to replace fluids leaving the body.
  • Carbon dioxide builds up in the body's cells, when the body temperature overheats. This leads to poor circulation.
  • Blood volume decreases. Your heart has to work harder because of dehydration, which means less blood volume in your body.
  • Breathing gets rapid. Breathing becomes fast and deep to increase oxygen level and decrease CO2 level.
  • Skin gets more blood. When body gets hot, more blood goes to skin surface and you sweat to cool blood and body.
  • Kidneys respond.  When body gets dehydrated, kidneys must work more to rid body of salt and to keep more water in body. Urine gets concentrated.

Suggested time:  Two 30-minute periods

Materials

Procedure

  1. Ask students: What is considered to be normal body temperature? Have students take their own temperature using a talking thermometer. Have the class plot these temperatures on a graph to find the mean value and the degree of variation. Each person can plot their own graph, using graphic aid, embossed graph paper, etc. Students can take their temperatures more than one time during the day: in the morning, after lunch, after gym class to demonstrate that the body temperature is maintained throughout the day and across days.
  2. Ask students: Why do you think there is so little difference in normal human body temperature while humans vary so much in other traits?
  3. Show students the Fever! video (use the alternate version with audio description) and have them examine the Function of Fever still image (and read the long description).
  4. Ask students: What can change the set point for body temperature? How does stress affect body temperature? What happens when you walk into the freezer aisles of a grocery store or a room that has the air conditioning set very cold? How does your body react (shivering, goosebumps) and how might this affect your body temperature?
  5. Ask students how fever is different from a rise in body temperature. What role might fever play in fighting infection? Have students generate list of signs and symptoms they have when they get a fever. Discuss how these symptoms are different from how you feel after you've done a little exercise.
  6. Have the class make predictions of how breathing and heartbeats will change after exercise and then conduct this experiment.
    1. Pair up and check your and partner’s heart rates using a stethoscope or a cardboard roll. Count the beats for 30 seconds and plot the numbers on a graph (you can use embossed graph paper, or graphic aids such as Wikki Stix, push pins, rubber or cork board).
    2. Next count the number of breaths you and your partner take in 30 seconds. Record your results and plot on the graph.
    3. Jump or run around the room for five minutes. Check your heart rates and respiration directly afterward and then again after a few minutes rest. Record your results and plot on the graph.
    4. Is there a difference between at rest and after exercise?
    5. How long did it take you to return to your "at rest" heart rate and breathing
    6. What other factors did you notice? Were you thirsty or hungry? Can you guess why?
  7.  Discuss the function of sweating and its role in homeostasis and fever. What happens when you sweat? Why wouldn't you want to exercise outside on a very hot day? Have students do this activity to explore the function of sweat.
    1. Blow on your forearm. How does your skin feel?
    2. Place a few drops of water on your forearm and rub it just a little bit.
    3. Blow on the wet spot.
    4. Does your skin feel any different than when you blew on it without the water? Discuss how blowing on the wet skin seemed cooler than when you did the same on dry skin. How is this helpful to your body when you have a fever?
  8.     Make a graphic organizer/flow chart to demonstrate the factors involved with maintaining body temperature (example below). This can be created as a raised line diagram or using collage materials and students can fill in areas in Braille.

 

Resources:

Teacher's Domain: Human Body Regulation

WGBH's National Center for Accessible Media

Collage with a voice thermometer and text "Regulating the Human Body: Teaching Homeostasis to Students with Visual Impairments"

 

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