1. Human Respiratory System
By: D. Reis

2. The Respiratory System
Air enters the respiratory system through both the nasal cavity and mouth.
The nasal cavity is lined with tiny hairs and mucus to trap foreign particles.
The air is warmed and moistened.

3. Respiration and Gas Exchange

4. The Respiratory System
Pharynx – where the nasal cavity and oral cavity meet
Epiglottis – flap that closes over the top of the trachea(glottis) due to reflexive action while eating
Trachea – the windpipe through which air passes
Supported by cartilage rings

5. The Respiratory System
Larynx – voicebox located in the trachea containing vocal cords. The vocal cords vibrate producing sounds.
Adam’s Apple – thick band of cartilage protecting larynx.

6. The Respiratory System
Bronchi – extend from the trachea also contains cartilage
Bronchioles – the smallest passageways of the respiratory tract
Alveoli – tiny air sacs where gas exchange occurs between the air and the blood

7. Alveoli Each lung is made up of 150 million alveoli.
Capillaries surround each cluster of alveoli and ensure
gas diffusion between the air and blood occurs.
Oxygen moves from the air inside the lungs to the alveoli while carbon dioxide moves from the alveoli into the air inside the lungs.
Lipoprotein prevents alveoli from sticking together

8. Goblet cells
Goblet cells – mucus secreting cells lining the trachea, bronchi and bronchioles to trap foreign particles.
Cilia - hair like structures that sweep the foreign particles up towards the mouth

9. Thoracic Cavity
External intercostal muscles – muscles between the ribs that raise the rib cage, increasing volume and reducing air pressure in chest.
Diaphragm – muscle that separates organs of the chest from abdominal cavity.

10. Pleural membrane – thin fluid-filled membrane surrounding lungs and inner wall of chest cavity that reduces friction during inhalation.

11. The Movement of Air
Air moves from an area of high pressure to an area of low pressure.
Air will move into the lungs when the air pressure inside the lungs is less than the air pressure outside the body.
Air will move out of the lungs when the air pressure inside the lungs is______ than the air pressure outside the body.

12. Inspiration (Inhaling)
The diaphragm contracts and moves down
External intercostal muscles expand rib cage upward and outward
Volume of thoracic cavity increases therefore air pressure decreases.
Movement of air into the lungs.

13. Expiration (Exhaling)
The diaphragm relaxes and moves up
External intercostal muscles move rib cage inward and downward.
Volume of thoracic cavity decreases therefore air pressure increases.
Movement of air out of the lungs.