1. Respiratory System Review What is air? Why do we need air? 21% oxygen
78% nitrogen
0.03% carbon dioxide
Why do we need air?
O2 + Glucose Water + CO2+Energy

2. The Respiratory System
Functions
Take oxygen from the atmosphere and deliver it to the bloodstream.
Take carbon dioxide from the bloodstream and expel it from the body.
This system works closely with the circulatory system.

3. The Respiratory System
Nasal Cavity: 2 cavities that contain hairs, cilia, mucous and a rich blood supply
Function:
Hairs and cilia filter particles
Mucous traps particles and moistens the air
Blood vessels warm air up to body temperature

4. The Respiratory System
Pharynx: muscular region at back of mouth
Function:
Passageway for air and food
Trachea: long tube lined with cilia (tiny hairs) and mucous
: made up of cartilage rings
Allows air to travel to and from the lungs
Cilia help filter out and remove dirt and bacteria from entering the lungs.
Dirt and bacteria are pushed up into the esophagus
Cilia cells in the trachea

5. The Respiratory System
Epiglottis: flap of skin at the top of the larynx
Function:
Prevents a bolus of food from entering the trachea
Larynx: box shaped part, made of cartilage and elastic folds called the vocal cords.
Produces sound
larynx video

6. The Respiratory System
Bronchi: 2 branches of trachea that contain carilage rings, mucous, and cilia
Function:
Delivers oxygen to each lung
Bronchiole: smaller branches of bronchi without cartilage and lined with smooth muscle
Deliver oxygen to alveoli

7. The Respiratory System
Alveoli: (alveolus = singular)
: small grape like sacs at the end of the bronchioles to maximize surface area
: measures 0.2 um in diameter
Function:
Allows for the diffusion of gases (O2 and CO2) between the air and blood.

8. The Respiratory System
Alveoli:
wall of alveolus is one cell layer thick
150 million per lung
Have a combine surface area of 90 m2
Surrounded by a network of capillaries (circulatory system)
Do Not Copy

9. This is where the Circulatory System and the Respiratory System meet and exchange gases!

10. The alveolus is covered by capillaries, which
carry the blood to the body.

11. O2 moves from the alveolus to capillaries through diffusion - movement from high concentration to low concentration. aka Inhaling
CO2 moves into alveolus by diffusion, collected from all the alveoli in the lungs and pushed back up and out the trachea to the mouth and nose. aka Exhaling

12. Question: How do you know when to inhale and exhale?
Video
Pig lungs
Question: How do you know when to inhale and exhale?

13. Breathing is involuntary, it is controlled by a part of the brain (Medulla Oblongata) that detects the concentration of CO2.
If CO2 is high, the brain
increases breathing.
If CO2 is low, the brain decreases breathing.
Homeostasis!!!

14. Mechanics of Breathing (How do we breathe?)
Inhaling:
rib muscles pull out and up, while diaphragm muscle contracts pulling down
Chest cavity volume increases resulting in a decreased air pressure
Air moves from area of high pressure (atmosphere) to low pressure (in the lungs)

15. Mechanics of Breathing (How do we breathe?)
Exhaling:
Rib muscles and diaphragm relax
Chest cavity volume decreases resulting in an increased air pressure
Air moves from area of high pressure (in the lungs) to low pressure (atmosphere)

17. Breathing:
Animation Animation 2

18. Respiratory Diseases:
Asthma
Chronic Bronchitis
Emphysema
Pneumonia
Influenza
Tuberculosis

19. Asthma
Bronchi are temporarily swollen and mucus restricts air flow. Person finds it hard to breath

20. Chronic Bronchitis
Bronchi are permanently swollen and have too much mucus. Person often coughs and breathless due to less O2

21. Emphysema
Alveoli (air sacs) collapse and/or are destroyed permanently. Less gas exchange = harder to get O2

22. Pneumonia
Alveoli fill with fluid caused by bacteria or viruses causing coughing, chest pain, fever, etc.