1. Respiratory System

3. Purpose-
Gas exchange of O2 and CO2 between the organism and the outside environment

4. Requirements for Gas exchange at the respiratory surface:
Thin-walled –(so gases can freely diffuse across)
Moist- (O2 and CO2 must be in solution or dissolved)
In contact with O2 source-(outside environment)
In contact with transport system carrying dissolved gases (Circulatory system/Blood)

5. Examples of gas respiratory surfaces used for exchange
Protists (Amoeba/Paramecium)
Surface: Cell membrane
Method: Simple direct diffusion through cell membrane to water
Earthworm
Surface: moist skin
Method: diffusion through moist mucus coated skin into blood vessels
(has hemoglobin to help)

6. Examples of gas respiratory surfaces used for exchange
Fish
Surface: Gills
Method: diffusion from water to blood vessels in the gills
Grasshopper
Surface: air tubes & sacs
Method: air comes in through spiracles, through the air tubes, moved by muscle contraction (no hemoglobin/blood used)

9. Human Respiratory System
Surface: Moist air sacs (alveoli)
Method: diffusion across air sacs into blood stream (use hemoglobin to increase amount of O2 that blood can carry)

10. Alveoli

11. Structures: Structure Function Voice Box- contains the vocal cords
Epiglottis
Covers the trachea, prevents food from entering the windpipe
Pharynx (Throat)
Throat area where air enters from the nose and mouth
Larynx
Voice Box- contains the vocal cords
Vocal cord
Bands of tissue stretched and relaxed to produce sound

12. Structures: Connects the mouth and the stomach for food Trachea
Windpipe- carries air from pharynx to and from the lungs
Cartilage rings to keep it open
C- shaped
Esophagus
Connects the mouth and the stomach for food
Lungs
Mass of air sacs (alveoli) where O2 and CO2 are exchanged
Nasal Cavity
Warms and cleans (filters) the air
Bronchi
Two branches of Trachea, connects the trachea to the bronchioles

13. Structures: Tiny air sacs in lungs where gas exchange occurs
Bronchioles
Tiny air tubes branching from the bronchi to the alveoli
Alveoli
Tiny air sacs in lungs where gas exchange occurs
(into the blood)
Diaphragm
Moves up and down causing pressure that forces air into and out of the lungs

15. Breathing Process Four Stages of Gas Exchange :
1. Breathing- movement of air in and out of the lungs
Inhalation - chest cavity increases
Diaphragm contracts (flattens) and lowers
Ribs raise up and out
Lungs inflate because during breathing negative pressure creates a vacuum which “sucks” air into the lungs

16. Four Stages of Gas Exchange :
Exhalation - chest cavity is decreases
Diaphragm relaxes and moves upward
Ribs drop down and in
Lungs deflate because positive pressure pushes the air out of the lungs

18. Four Stages of Gas Exchange :
2. External respiration- exchange of gases between outside air and bloodstream in the air sacs
Mucus coats air sacs (alveoli) to moisten them
O2 diffuses across air sacs into capillaries of air sacs and CO2 diffuses in the opposite direction
O2 attaches itself to hemoglobin on the red blood cells

19. Four Stages of Gas Exchange :
3. Transport- movement of gases in the blood between the cells to the lungs (circulatory system)
4. Internal respiration- exchange of gases between the blood stream and the cells of the body
At the capillaries, O2 diffuses into the intracellular fluid and then into the body cells & CO2 diffuses in the opposite direction

20. CO2 Transport
80% of CO2 dissolves in the Plasma and/or combines with water in the plasma to make carbonic acid (H2CO3)
20% of CO2 is carried by hemoglobin back to lungs

21. Respiratory Disorders
Asthma- severe allergic reaction where bronchioles go into spasm and squeeze air passages making it difficult to breathe
Treatment- medication (inhaler)

23. Respiratory Disorders
Bronchitis- Bronchial tubes become irritated and swollen, and alveoli become swollen and clogged with mucus making it difficult to breathe
Treatment- antibiotics if bacterial infection

25. Respiratory Disorders
Emphysema- lungs lose their elasticity and the air sacs become damaged and it leads to shallow breathing and even death. Most disease is caused by years of smoking.
Treatment- stop smoking and use of O2 tank for additional help

27. Respiratory Disorders
Cystic Fibrosis- Body produces too much mucus and the person is unable to breathe and have frequent infections
Treatment- gene therapy