Exercise and Breathing

Learning Objectives• Can you label a diagram of the thorax, including the

ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes?

• Can you explain how the intercostal muscles and the diaphragm are used in ventilation?

• How is diffusion involved with gas exchange?• Can you explain how alveoli are adapted for gas

exchange?• What kind of experiment could you do to investigate

the effect of exercise on breathing rate in humans?

Copyright © 2014 Henry Exham

The Gaseous Exchange System

Pleural membranes

Bronchi

Bronchiole

Alveoli

Ribs

Intercostal muscles

Lungs

Nose

Mouth

Trachea

Diaphragm


Structure Function

Trachea Tube with incomplete rings of cartilage carries air to lungs; lined with cells making mucus, and cells with cilia to move the mucus away.

Bronchi Carries air to lungs

Bronchioles Carry air to lungs

Alveoli Tiny air sacs adapted for gas exchange

Diaphragm Sheet of muscle with a fibrous middle part which is domed; it helps make breathing movements and separates the thorax from the abdomen

Ribs Bones that protect and ventilate the lungs

Intercostal muscles Move ribs for ventilation

Pleural membranes Thin moist membranes forming an airtight seal around the lungs and separating inside of thorax from lungs

The Gaseous Exchange SystemCopyright © 2014 Henry Exham

Ventilation of the lungs• Ventilation means moving air in and out of the

lungs.• This requires a difference in air pressure and

relies on the thorax being an airtight cavity.• Movements of the intercostal muscles and

diaphragm change the volume inside the cavity and therefore the air pressure.

• This causes the air to move in or out.


Inhalation

∂∂

∂∂

∂∂

Side view of thorax

Diaphragm

Lungs

Ribs

Intercostal muscles


Inhalation

∂∂

∂∂

∂∂

1

2

3

4

5Intercostal muscles contract

Ribs pulled up and out

Diaphragm contracts and flattens

Volume of thorax increases which reduces the pressure.

Therefore air moves into lungs.


Exhalation

∂∂

∂∂

3

4

Diaphragm relaxes and returns to dome shape.

Volume of thorax decreases which increases the pressure.

Therefore air forced out of lungs.

51

2

Intercostal muscles relax

Ribs move down and in


Gas exchange in the alveoli• The lungs contain 700,000,000 tiny air sacs called

alveoli.• They are surrounded by a network of blood capillaries. • Carbon dioxide diffuses from the blood into the air in

the alveoli. • Oxygen diffuses from the air in the lungs into the

blood.• The oxygenated blood then travels back to the heart to

be pumped around the body.


Structure of the alveoli• Each alveoli is surrounded

by blood capillaries. • These carry deoxygenated

blood.• The carbon dioxide that is

carried by the blood diffuses into the alveoli to be exhaled.

• The oxygen diffuses into the blood from the alveoli and binds to the red blood cells.

air in and out

Oxygen

Carbon dioxide

Oxygenated blood

Deoxygenated blood

Red

bloo

d ce

ll

Capillary


Adaptations of the alveoli• They have a large surface area for diffusion.• Fluid to help dissolve gases and increase diffusion rate.• A rich blood supply to maintain a steep diffusion

gradient between the alveoli and the blood.• Due to both the alveoli and the capillary only having

walls one cell thick there is a short diffusion distance between the air and the blood which increases diffusion rate.


Exercise and BreathingWhat I know What I want to know What I learned

Investigate the effect of exercise on breathing rate.

• It is also interesting to see what happens to breathing rate immediately after exercise.

Click on the above image to see some typical results for a normal and fit person.


http://www.abpischools.org.uk/res/coResourceImport/modules/breathingandasthma/fullscreenflash6-1.cfm


• First you must determine your resting breathing rate.

• Count how many times you inhale in a minute.• Do this three times and take an average. • This will make your data more reliable.



• Then you must calculate your breathing rate carrying out exercise.

• Jog on the spot for one minute and count the breaths you inhale in that time.

• Then take a minute to rest.• Once again repeat the experiment two more times and take the average of all three results.



• You should find that breathing rate increases as you exercise.

• This is to provide your muscles with more oxygen which it can use for aerobic respiration to release energy.


The question I am investigating is………..

My independent variable (what I am changing) is…

We will change our independent variable by….I plan to test these values/this range…..because….

My dependent variable (the one I am measuring) is…

I will measure my dependent variable by….

The units I will measure it in are…

The variables I will need to control (keep the same) are…..

I will keep these variables the same, to make it a fair test, in this way….

Variables that I might not be able to control properly are…Because…

I predict that….

Because….

The step-by-step method I plan to follow is…

1.

2.

Method is in correct orderMethod contains more than one approach

Diagrams to help explain the method….

Labelled, detailed, accurate

The safety features of my experiment are….

The reasons I need these safety features are…

To make my investigation experiment reliable I will….

More than one suggestion

My results table will look like this….

Have included units

The equipment I need for this experiment is….

Sizes/ details /correct equipment names

The scientific knowledge we have used to make our prediction is…

DETAIL! JUSTIFY YOUR METHOD! NAME YOUR SOURCESB

H

M

B

M/H

M

M

M

B

B

B

M

B

BIOLOGYI am hoping to find out……….. M

H

M

B

M

M

HH

H

H

Final Product• You are a qualified G.P. and you have a patient that has been

diagnosed with a mild case of emphysema. The patient is a smoker and is reluctant to stop because they think it’s cool. Create an informative and persuasive argument to present to your patient next time you see them.– The chemicals in smoke and their effects on the body– Emphysema – short and long term effects– Other effects of smoking e.g. lung cancer and coronary heart diseaseYou may work in pairs or individually and present your argument how you wish e.g. presentation, poster ...You must have a printed version for your exercise book or as a classroom display.

DUE MONDAY OCTOBER 12.

Exercise and Breathing

Education