1. Ch. 17.1 The Respiratory System

2. 17.1.1 What are the functions of the respiratory system?

3. Respiratory System Functions
ALL the cells in your body need oxygen.
This oxygen comes from the air you breathe.
The respiratory system moves oxygen from the outside environment into the body.
It also removes carbon dioxide and water from the body.
Oxygen 
Carbon dioxide 
Water 

4. Taking in Oxygen The oxygen your body needs comes from the atmosphere.
Air ≠ Oxygen!
Air = ALL the gasses in the atmosphere:
78% of the air is NITROGEN!
Only 21% is Oxygen

5. Cellular Respiration Respiration is NOT breathing.
It is the chemical process in which oxygen and glucose react to release energy inside the body cells.
It is the opposite of Photosynthesis.

6. Removing Carbon Dioxide and Water
CO2
H2O
Not only does the body breath in Oxygen for all your cells, it also gets rid of Carbon Dioxide AND Water!
This is why you can see your breath in cold weather.
CO2
H2O
H2O
CO2

7. Systems Working Together
The respiratory system is just one of the body systems that make respiration possible.
Your respiratory system brings oxygen into your lungs.
Your digestive system absorbs glucose from the food you eat.
Then your circulatory system carries both the oxygen and glucose to your cells so they can function!

8. 17.1.2 What structures does air pass through as it travels to the lungs?

9. The Path of Air
Have you ever seen dust floating in a shaft of bright light?

10. These particles include things like floating dust, plant pollen, and ash from fires.

11. When you breathe, all these things go into your body as well as the air.
Most of these things never reach your lungs.
You have a natural air filter built right into your body!
Your NOSE!

12. As air travels from the outside environment to the lungs, it passes through the following structures:
Nose
Pharynx (throat)
Trachea
Bronchi
Alveoli

13. The Nose Your nose produces mucus.
This sticky substance is meant to catch dust, pollen and other yucky stuff.
It turns into buggers.
Mucus also keeps the nose from drying out.

14. Inside your nose, you have tiny little hairs called cilia
Inside your nose, you have tiny little hairs called cilia. (these are not the hairs growing out of grandpa’s nose)… that’s just long regular hairs…
Cilia act like a broom and push all the dust, pollen, etc. to the throat (nasal drainage) so you can swallow it to the stomach where the acid kills it, or you can spit it out.
When they are tickled, you sneeze!

15. The Pharynx
From the nose, the air passes through the throat or Pharynx.
It is the only part of the respiratory system that is also shared with another system – the digestive system.

16. The Trachea
From the Pharynx, air moves into the windpipe: aka: The Trachea
The trachea fells like a tube with a series of ridges.
The firm ridges are rings of cartilage that strengthen the trachea and keep it open.
The trachea is also lined with little hairs called cilia. They move stuff from the lungs back to the throat/pharynx so you can spit/swallow.

17. Wrong tube!
If you accidentally swallow food into the trachea, you choke!
Thankfully the epiglottis, the flap that covers the esophagus and trachea help direct food to the right direction so you don’t choke.
Just be sure to chew with your mouth closed (this means you aren’t talking while eating) so your epiglottis know where to be ;)

18. Bronchi Bronchi is Latin for “branches” They look like tree branches!
They take oxygen from the trachea to the lungs.
When you are sick and the bronchi are swollen, it is called Bronchitis.
itis means “swollen”

19. Lungs At the end of these tree branches are tiny bunches of “grapes”.
These “grapes” are called alveoli.
They are tiny sacs of lung tissue specialized for the movement of gases between air and blood.

20. 17.1.3 What happens during gas exchange and breathing?

21. Gas Exchange
Gas exchange = trading oxygen for carbon dioxide and water.
Gas exchange occurs in the alveoli.
Because the walls of both the alveoli and capillaries are very thin, certain materials can pass through them easily.

22. Carbon dioxide and water pass from the blood into the alveoli.
After air enters an alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood.
Carbon dioxide and water pass from the blood into the alveoli.
This whole process is known as gas exchange.

23. How does that work?
You have about 300 million alveoli! That’s a HUGE number!
The huge surface area of the alveoli enables the lungs to absorb a large amount of oxygen.

24. How you breathe
In an average day, you may breathe more than 20,000 times.
If you are working out, you need more oxygen.
This is why you breathe harder and faster when running!

25. Muscles for Breathing Breathing is controlled by muscles.
Most importantly is the diaphragm.
It is a large, dome shaped muscle at the base of your ribs.

26. The Process of Breathing
When you breathe, the actions of your rib muscles and diaphragm expand or contract your chest.
As a result, air flows in or out.
When the diaphragm contracts and pulls down, it pulls oxygen into the lungs.
(diaphragm contracts  air pressure decreases  breathe in)

27. When the diaphragm relaxes back to the up position, it pushes carbon dioxide out of the body.
(diaphragm relaxes  air pressure INCREASES  breathe out)

28. Relating Breathing and Speaking
The air that moves out of your lungs as you breath are also used to speak.
Inside the larynx is the voice box which contains the vocal cords.
They are in the “Adam’s Apple”.
Men have a larger Adam’s Apple, and therefore, typically, lower voices.
If they are damaged, you can lose your voice.