respiratory system

Respiratory system
A.Introduce
We normally breathe without thinking about it. Our respiratory rate also usually adjusts to changes in our activity levels without any conscious effort on our part.
The changes in breathing, both rate and depth, are largely regulated by chemical changes in the blood.
The following reaction illustrates this concept:
CO2+H20→H++HCO3-
B. Hypothesis statement
Human body will adapt to changes and respond to disruptions in homeostasis.
There must be some relationship of the respiratory system to some sort of disturbance in equilibrium of the respiratory system.
c. suspect
As the carbon dioxide levels increase in the blood, carbonic acid forms which then dissociates to form bicarbonate ion and release hydrogen ions, resulting in a decrease in pH. This stimulates the respiratory center and reflex breathing occurs.
As carbon dioxide is removed, the reaction proceeds to the left, thus removing hydrogen ions and forming more carbon dioxide for liberation from the body. Normally, the rate of carbon dioxide production by the tissues of the body is matched to the respiratory rate.
C. variables:
The depth of breathing that will result of carbon dioxide level in the lungs.
D. material and methods:
Material:
We need a Stopwatch in this experience to calculate the time.
The purpose of the following exercises is to investigate some of the factors that affect the rate and depth of breathing.
Method:
1. Time how long you can hold your breath after a quiet inspiration
2. Time how long you can hold your breath after a deep inspiration (inhale as deeply
as possible, and then hold your breath)
3. Time how long you can hold your breath following a quiet expiration.
4. Breathe deeply and forcefully at a rate of about 1 breath/3 seconds, 20 times (hyperventilate).
Time how long you can hold your breath.
5 run down the hall and back again or go down to the first floor and come back up quickly. Then immediately hold your breath for as long as possible. Record the time.
E. data
The longest time you can hold your breath is the step 4 which is 20 times breathe deeply.
F. results:
The heart is influence by the deep of breath. More deeply more time we can hold.
A deep breath means we inhale more air in lungs. To do this, we increase the area of lungs and let more air exchange. In procedure 4, 20 times deeply breathe make us have higher level of O2 than normal. This means we can hold much longer time. When the level of O2 is too low in lung, we must take a breath unconscious. In procedure 3, because we hold breathe following a quiet expiration. There is less air
that we will get low level of O2 quickly and hold less time.
After exercises, we made more CO2which may lead to dizziness. We voluntary control the level of CO2 and increase the O2 level. Breathe will become more deeply and more quickly. In experience, we just can hold 13 second which much shorter than normal.
G. improvement
We just have 5 procedures because there is not much time in class. And we need more experience. For example, we can time the breath after jump, stand, walk and run that make the result persuasive.
For each procedure, we can do several times to make the result more accuracy. Because there must be many reasons influence the result.。