Homeostasis Lab
10-30-13
Learning Target
Students will write
short paragraphs
describing what
homeostasis is and
how the nervous
system is involved.
Homeostasis
 Body’s ability to maintain basic stability
internally with response to external
stimuli.
 It is the body’s way to “fix” itself when
things go a little wrong.
 Examples: too hot = sweat, too cold =
shiver, build up pressure in your stomach
= burp, built up pressure in bowels = fart.
 Other examples?
“Can’t Take My Eyes Off Of You”
1. A student will have a flashlight shun in their eyes
multiple times, HYPOTHESIZE/CLAIM what will happen
to the pupil/iris when the flashlight is turned on.
2. PROCEDURE
a. Need 1 volunteer in each group to operate flashlight.
b. Need 1 volunteer to perform experiment.
c. Other group members are expected to look closely
at the eye-opener’s eyes when the flashlight is
turned on.
d. Repeat step C 2 more times.
3. DATA/EVIDENCE
a. WRITE down what happened to the pupil/iris.
4. CONCLUSION/REASONING
a. WRITE down WHY you think the pupil/iris was
affected in that way.
“Oh My Beating Heart!”
Where to take your pulse: On your jugular
vein or your wrist.
1. Take your pulse. I will time for 60
seconds.
2. Continue taking your pulse.
3. Answer these questions in your notebook:
a. What did you observe?
b. When have you noticed your heart rate
rising before?
c. Under what circumstances?
d. Why does it happen?
Fight or Flight
 CLAIM: An increase in obnoxious stimulus causes an
increase in heart and breathing rates, which keeps the
body balanced.
EVIDENCE
REASONING
Heart rate increased.
More oxygen had to be transported by the
circulatory system to cells and carbon dioxide
had to be delivered from the cells to the lungs.
Breathing rate increased.
Recovery to original heart and breathing rates
occurred.
More oxygen and carbon dioxide is exchanged
by the respiratory system by way of diffusion
across the alveolar membranes.
Oxygen and carbon dioxide levels returned to
normal as a result of removing the external
stimuli. (and the pH has been neutralized)