1. Human Respiration Involves cellular respiration and gas exchange in lungs Cellular Respiration – Aerobic- with oxygen – Anaerobic- without oxygen. Lactic acid is produced

2. Structures of the Human Respiratory System Nose: Nasal cavity – Air enters the two nostrils. Air is filtered, warmed, and moistened (cilia & mucus).

3. Pharynx Throat. Where oral and nasal cavity meet. Two tubes lead downward trachea & esophagus. – Epiglottis prevents choking by covering trachea when eating/drinking

4. Epiglottis Flap that closes over trachea and prevents food from entering.

5. Larynx Voicebox/ “adams apple”

6. Trachea Aka: windpipe- 4.5 inches long. Extends from the larynx to the bronchi. Kept open by rings of cartilage. Ciliated mucous membrane lines the trachea.

7. Bronchi Two major divisions (branches) of the trachea. Lined with mucous membranes. Ringed with cartilage Subdivide (branch)into bronchioles.

8. Bronchioles Subdivision of the bronchial tubes Lined with mucous membrane No cartilage rings End with alveoli – Air sacs

9. Alveoli (aka air sacs) Functional units for gas exchange - DIFFUSION Thin, moist walls ( one cell layer thick) Surrounded by capillaries

10. Lungs Make up large part of the chest cavity Enclosed within a ribcage Each lung contains bronchus with it’s bronchioles and alveoli. Pleura- protective outer covering.

11. Diaphragm Sheet of muscle separating chest (thoracic) cavity from abdominal cavity Controls Breathing

12. Breathing Rate Depends on Carbon Dioxide in the blood Controlled by the Medulla (base of brain) Diaphragm: Contracts-Air in (inhale) Relaxes-Air out (exhale)

13. Malfunctions of the Respiratory System: Asthma: Allergic response, can also be triggered by exercise. Bronchioles constrict and prevents air flow. Causes breathing difficulty.

14. Bronchitis: Inflammation of the bronchiole tubes

15. Emphysema: Destroys Alveoli, less surface area for gas exchange. Caused by smoking!

16. Pneumonia: Caused by bacteria, alveoli fills with fluid.

17. Lung Cancer: Tumors form in lungs (uncontrolled cell growth). Caused by smoking!