1. The Respiratory System
Unit Three
The Respiratory System

2. Learning Goal
To take a closer look at parts of human respiratory system
To learn more about the function of the respiratory system and gas exchange

3. Introduction
Most of the cells in our bodies need a continual supply of Oxygen (O2) to carry out cellular respiration
This process releases energy from glucose inside cells and produces Carbon Dioxide (CO2) as a waste product
The left over chemical energy is used for the cell to carry out activities (cellular respiration – Gr. 12)

4. Introduction
The structure of the respiratory system can be divided into2 main groups:
The Upper Respiratory Tract
The Lower Respiratory Tract

5. The Upper Respiratory Tract
Air enters through the nose and mouth into the nasal cavity
The NASAL CAVITY is lines with nose hairs and mucus to catch dust, bacteria, and other particles that were inhales with the air but are bad for the body

6. The Upper Respiratory Tract
Air then travels into the PHARYNX (throat)
Both inhaled air and food pass through the pharynx from the nasal and oral cavity
From here air passes into the LARYNX (vocal cords)

7. The Upper Respiratory Tract
A muscular tissue called the epiglottis works like a swing door opening on purpose for air to enter into the larynx and keeping food out, and vice versa, from food entering the esophagus and not into the larynx

8. The Upper Respiratory Tract
From the larynx air flows into a tube called the TRACHEA (windpipe)
The trachea is lined with cilia hairs and mucus to trap pollutants and other particles that made it past the nasal cavity when breathed in

9. The Lower Respiratory Tract
Includes the lungs, bronchi, bronchioles, and alveoli
Air continues to flow from the trachea down towards the lungs
Inside the lungs are two branching tubes called BRONCHI

10. The Lower Respiratory Tract
These bronchi then also are broken down into a smaller branches of smaller tubes called BRONCHIOLES
Each lobe has its own amount of bronchioles
This is beneficial in case one lobe gets injured – the other can still function and supply air to the tissues of the lungs

11. The Lower Respiratory Tract
The smallest bronchioles end at a cluster of tiny air pockets called ALVEOLI
Here O2 from the air we breathe in enters the alveoli and diffuses into the capillaries around them at the same time CO2 in the blood diffuses into the air in the alveoli
* Remember diffusion = movement of a particle from a HIGHT concentrated
area to a LOW concentrated area*

12. Review of Anatomy
(1:45)
2:30)

13. Introduction – Terms
Respiratory System – is the group of organs that provide living things with oxygen from outside the body and disposes of waste products like CO2
Respiration – all the processes involved in bringing O2 into the body, making it available to each cell, and eliminating CO2 as waste

14. Respiration & Gas Exchange
There are Four Stages in human respiration, where each stage has specialized structures to help it:
Breathing
External Respiration
Internal Respiration
Cellular Respiration

15. Respiration & Gas Exchange
Stage 1 – Breathing
Involves Inhalation (breathing in) and Expiration (breathing out)
Inhalation – moves air from outside the body into the lungs inside the body
Expiration – moves air from the lungs back to the outside of the body

16. Respiration & Gas Exchange

17. Respiration & Gas Exchange
The inhaled air that enters the alveoli have a greater [ ] of O2 than CO2
The blood that circulates in the capillaries surrounding the alveoli has a greater [ ] of CO2 than O2
The differences in these concentration make a Concentration Gradient that helps gas exchange happen (step 2)

18. Respiration & Gas Exchange
Step 2 – External Respiration
Here, CO2 and O2 is exchanged between the inside of the lungs and the blood
This stage is VERY IMPORTANT to our existence via the Gas Exchange Process
Is the Delivery of O2 from the lungs to the blood
Is the Elimination of CO2 from the blood to the lungs

19. Respiration & Gas Exchange
In the lungs, oxygen diffuses from air in the alveoli into blood in the capillaries
At the same time, carbon dioxide diffuses from the blood into the air in the alveoli
The carbon dioxide leaves the lungs and exits through your mouth as you breathe out

20. Understanding Gas Exchange
We see that the thin walls of the alveoli and the capillaries allow gases to diffuse through their cell membrane easily

21. Respiration & Gas Exchange

22. Animation

23. Understanding Gas Exchange

24. Understanding Gas Exchange
As you can see, the air that enters the alveoli AFTER inhalation has a higher [ ] of O2 than the blood in the capillaries next to the lungs

25. Understanding Gas Exchange
Thus, oxygen diffuses out of the alveoli into the blood in the capillaries

26. Understanding Gas Exchange
The blood in the capillaries has a HIGHER concentration of CO2 than the air in the alveoli
This is because CO2 is a waste produce of cellular respiration (step #4) and is brought up to the lungs from other cells in the body to be exhaled out

27. Understanding Gas Exchange
Therefore, the body gets rid of CO2 (waste product) by having it move out from the capillaries and into the alveoli
The CO2 is then exhaled out into the air and out of the body as NEW and FRESH O2 is breathed in and the cycle continues

28. Understanding Gas Exchange
The reason why CO2 is able to move out of the capillaries and into the alveoli to be exhaled out
And the reason why O2 is able to move from the alveoli and into the capillaries with fresh O2 for cells
Is because of DIFFUSION – The movement of a substance from a High concentration to a Low concentration

29. Understanding Gas Exchange
Where:
There is a high [ ] of CO2 in capillaries and moves to the low [ ] area of the alveoli
There is a high [ ] of O2 in the Alveoli from being breathed in and moves to the low [ ] of the capillaries in the blood

30. Respiration & Gas Exchange
Step 3 – Internal Respiration
Is the exchange of O2 and CO2 between the blood and the body’s tissues

32. Respiration & Gas Exchange
Stage #4 – Cellular Respiration
Is a bunch of reactions that work to make energy inside of cells where they:
USE OXYGEN
RELEASE CARBON DIOXIDE (waste)

33. Checking for Understanding
What’s the difference between “Breathing” and “Respiration”?
Answer:
Respiratory refers to the chemical reaction inside cells.
Breathing refers to the movement of air into and out of the lungs.

34. Activity!

35. Review http://www.dnatube.com/video/6094/Gas-Exchange-in-the-Lungs

36. Understanding Gas Exchange

37. How do these gases move around in the body?
During respiration, both oxygen (O2) and carbon dioxide (CO2) are transported via the bloodstream
99% of O2 that reaches cells is carried by Hemoglobin (Hb)
Is a protein in RBC that is attracted to O2

38. How do these gases move around in the body?
When CO2 leaves tissue cells and diffuses into the capillaries, it enters the RBC
23% of CO2 is carried in the blood by Hemoglobin
The other 77% is in the blood as a dissolved gas
When CO2 reaches the lungs, it diffuses into the air in the alveoli and is exhaled

39. How do these gases move around in the body?