The Respitory System

1. Warm Up!
Get your journal to take notes.

2. The Respiratory System
Weird.

3. #1 First, a Review
•Function = job
•Homeostasis = equilibrium for the body. Your body tries
to maintain a healthy balance of all things.
•Stimulus/response = how your body reacts to situations
and messages that require action.
Easy. No heart
attacks this time,
right?
Sure, Joe…no heart attacks. No other promises, though.

4. #2 Respiratory System
Overview
Why do we need to breathe?
If you say, “because we need oxygen to live,” then explain
why we need oxygen.
It’s because the sugar you eat (glucose) that serves as the primary
source of energy for your body really acts as a storage box of energy.
To get that energy free from the glucose so that your cells can use it,
your cells carry out a process called respiration that involves reacting
glucose with oxygen to free up energy.
You get the glucose from digesting food, and yep, you get the oxygen
from breathing. THAT’s why you have to breathe to stay alive.
Glucose + O2  water (waste) + CO2 (waste) + ENERGY!
Cellular Respiration

5. #3 Resp. System Overview,
Cont.
The respiratory system’s main job is to exchange gases in
the lungs.
The whole system…
All your cells are doing…

6. #4 FUNCTIONS of the Resp.
Sys.
1. Gets oxygen from air for body’s cells (inhaling)
2. Gets rid of carbon dioxide waste from cells (exhaling)
3. Allows us to speak
Pretty important stuff for our
survival & “advancement” as a
society, huh.

7. #5 How do we actually breathe?
What actually causes air to fill our lungs when we breathe in???
Well, you see, the contraction of the diaphragm
muscle in the mid-torso causes an expansion of
volume in the lung cavities…this expansion creates a
pressure gradient, or vacuum, that acts as a FORCE
pulling air into the lungs.
In “English,” the diaphragm muscle (in red) pulls
down on the lungs, making them bigger, which creates
empty space (a vacuum) that air rushes in to fill. When
we exhale, the diaphragm just pushes up on the lungs,
like when you squeeze a balloon to let the air out quicker.

8. Nose/Sinuses
#6 STRUCTURES of the
Respiratory System
The respiratory system is laid out as a tract. A tract is a series of organs
that are arranged one after another. The digestive tract is another
example. Let’s start as air comes in while you inhale.
Be sure to label your sketch on the back of your notes as we go
through these organs!
1. Nose/sinuses – make air warm, moist, and clean (hairs/mucus).
Sinuses affect your voice.
The nose is just better at preparing
air for your lungs than your mouth
is. Breathing through your nose is
usually just flat-out better.

9. #7 Structures, contd.
Once cleaned & prepped by your nose, the air continues back toward
your throat.
2. Pharynx – throat…both food and air pass. Epiglottis keeps you from
choking on food/drinks.
3. Larynx – vocal cords: vibrate to make noise as you exhale. In
combination with the different shapes your tongue, lips, etc. can form,
you have the ability to make hundreds of different sounds.
Place your
Finger on your
larynx and
make these
sounds:
s, z, p, b, f, v

10. #8 Structures, contd.
Air continues on its journey to the lungs…
4. Trachea – windpipe. This is held open by rings of cartilage so that
it doesn’t collapse shut when you inhale. The trachea splits into two…
5. Bronchi/bronchioles – smaller passages that split heading into the
lungs.
Well, now we’re
getting closer to
air’s final
destination.

11. #9 Structures, contd.
Air is now finally inside the…
6. Lungs – spongy organs filled with alveoli—tiny air sacs that have
two jobs:
a. stuff O2 into capillaries (where RBCs will carry it to body)
b. allow CO2 into bronchioles (where it can be exhaled out)
bronchioles end as alveoli &
are surrounded by capillaries
gas exchange between alveoli
and capillaries

12. #10 Structures, contd.
And of course, since the organs make a tract, air just reverses through
them as the diaphragm pushes and you exhale.
Every time you exhale,
you release waste gases into
the air, or into a bubble, into
a trumpet, or whatever.
Plants love it though…our
waste is their treasure!

13. #11 DISORDERS of the
Respiratory System
Boy, what an important set of organs for your survival. No wonder
you can hold your breath only so long before your body says, “enough,
you’re being foolish” and forces you to breathe despite your efforts.
So, take care of your respiratory system. Seriously. Let’s see what can
happen if it doesn’t function properly or if you abuse what you were
given.
I don’t like how this
sounds…what are
you gonna do to me?
Let’s say that Joe has been a chain-smoker for many years…

14. #12 Disorders, contd.
Smoking kills little hairs in
your respiratory tract that
move mucus around. This
causes that annoying
“smoker’s cough” that you
often hear. It causes an
extreme shortness of breath
called emphysema, which
would affect your daily life.
And of course, it often
leads to…

15. #13 Disorders, contd.
Man, I’m tired. I’ve
gotta take a break.
Smoking is probably the most
harmful way in which you can
damage your respiratory system
on purpose. Avoiding its problems
is easy…just don’t start. It
might’ve seemed cool &
rebellious 20 years ago, but now
most people realize it’s just dumb.
Let’s give Joe a break—he kicks
the habit. 

16. #14 Disorders, contd.
There are several disorders that aren’t necessarily somebody’s “fault”
for having. You’ve heard of at least a couple of these, I’m sure.
1. Bronchitis – “itis” means “inflammation or infection of…” So, this
is some sort of irritation of your bronchial passages often resulting in
coughing and maybe phlegm. Your doctor can find which medicine
will kick this to the curb.
*hack*
*cough*
#@$%!
*hack*

17. #15 Disorders, contd.
2. Asthma – there are lots
of causes of asthma,
and some pretty easy-
to-use treatments. Asthma
occurs when your
bronchial passages
inflame, causing them to
shrink up and make
breathing difficult.

18. #16 Disorders, contd.
One condition that genetic researchers are still trying to cure is called:
3. Cystic Fibrosis – This is a build-up of thick mucus in the lungs…this
mucus must be loosened and coughed up very often. Cystic Fibrosis
is genetic, and appears almost instantly in newborns. The problems this
mucus causes the lungs and digestive system usually results in pretty
serious health concerns as the people enter their 20s and 30s.

19. #17 Review
Just like last time, we’ll review the Respiratory System by seeing what
would happen if it stopped functioning.
1. Gets oxygen from air for body’s cells (inhaling)
Joe would quickly go unconscious as his brain cells fall asleep
and he’d die within 5 to 30 minutes.
2. Gets rid of carbon dioxide waste from cells (exhaling)
Joe would build-up CO2 in his blood, slowly poisoning himself.
He’d get a bad headache and feel very tired until he fell into a coma
and died of blood poisoning as his organs shut down one by one.
3. Allows us to speak
Joe would not be able to communicate as easily, and would need to
learn sign-language or carry around paper & pen everywhere.

20. #18 Review
How does the Respiratory System maintain homeostasis?
By maintaining the proper amounts of oxygen and carbon dioxide
in your blood, that’s how.
Stimulus : Response
(something you respond to) : (the response)
Tiring muscles while exercising : faster breathing rate to supply more
oxygen to those muscles

21. #19 And That’s…