The respiratory system functions to oxygenate the blood and remove carbon dioxide through gas exchange that occurs in the alveoli of the lungs. It is organized into an upper respiratory tract including the nose and pharynx, and a lower respiratory tract including the larynx, trachea, bronchi, and lungs. The lungs are paired organs located in the thoracic cavity that contain alveoli which are the sites of gas exchange between the respiratory and circulatory systems.

1. RESPIRATORY SYSTEM

2. RESPIRATORY SYSTEM
FUNCTIONS
Gas Exchange (pick-up O2, eliminate CO2)
Filter, Warm & Humidify Air
Protection
Speech
Regulate pH

3. RESPIRATORY SYTEM
ORGANIZATION
Upper Respiratory Tract (Outside Thorax)
- Nose
- Pharynx
Lower Respiratory Tract (Inside Thorax)
- Larynx
- Trachea
- Bronchial Tree
- Lungs

5. UPPER RESPIRATORY
TRACT
Nose
- External Nares/Anterior Nasal Aperture
(nostril)
- Nasal Cavity
*Hairs, Mucus (Trap Debris)
*Mucosa (Warm, Moisten)
*Cilia (Transport)
*Nasal Conchae Bones (Turbulence)
*Olfactory Receptors (Smell)
*Tear Drainage

6. UPPER RESPIRATORY
TRACT continued
- Paranasal Sinuses (4)
*Spaces in Bone
*Lined with Mucous Membrane
*Empty into Nasal Cavity
*Light Bone, Resonation
- Internal Nares/Posterior Nasal Aperture

7. UPPER RESPIRATORY
TRACT continued
Pharynx (Throat)
- Between Nasal Cavity & Larynx
- Passageway for Air & Food
- 3 Divisions:
*Nasopharynx
*Oropharynx
*Laryngopharynx

8. UPPER RESPIRATORY
TRACT continued
- Protected by Tonsils:
*Pharyngeal Tonsil (“Adenoids”,
Nasopharynx)
*Tubal Tonsils (Nasopharynx, Entrance
to Auditory Tubes)
*Palatine Tonsils (Oropharynx)
*Lingual Tonsils (Oropharynx)

9. LOWER RESPIRATORY
TRACT
Larynx (Hyoid → Cricoid Cartilage)
- 2 Functions:
*Keep Movement of Food & Air
Separate
*Provide Sound for Speech
- Glottis
*Slit-like Opening into Larynx
*Produces Speech with Vocal Cords

10. LOWER RESPIRATORY
TRACT continued
- Cartilages:
*Epiglottis
Covers Glottis (opening of larynx)
Prevents food from Entering Trachea
*Thyroid (“Adam’s Apple”)
*Cricoid (Inferior, Encircles Vocal
Cords)

11. LOWER RESPIRATORY
TRACT continued
Trachea (“Windpipe”)
- “C”-Shaped Tracheal Cartilage Prevents
Collapse
- No Cartilage Posterior, Allows Swallowing
Bronchial Tree
- Branching Airway
- Carina (Ridge at Bifurcation of Trachea)
- Supported by Cartilage

12. LUNGS
Paired (“spongy”) Organs
Surfaces
- Apex (Superior extension, above
clavicle)
- Hilum (Vertical slit on medial surface)
- Cardiac Notch (Recess on left lung)
- Base (Inferior, rests on diaphragm)

13. LOWER RESPIRATORY
TRACT/Lungs continued
Located in thoracic cavity, lateral to heart,
superior to diaphragm
Protected by pleura (serous membrane)
- Visceral (inner, covers lung surface)
- Parietal (outer, lines thoracic cavity)

14. LOWER RESPIRATORY
TRACT/Lungs continued
- Lobes
* Right Lung - 3 Lobes: Superior, Middle,
Inferior
* Left Lung - 2 Lobes: Superior, Inferior
- Fissures
* Horizontal Fissure (Between Superior & Middle
Lobes, Right Lung)
* Right Oblique Fissure (Middle & Inferior)
* Left Oblique Fissure (Superior & Inferior)

15. LOWER RESPIRATORY
TRACT/Lungs continued
- Alveoli
*Microscopic, Membranous Air Sacs
*Functional Unit of Lungs, Main Site of
Gas Exchange Between Respiratory &
Circulatory Systems (by diffusion)
*Simple Squamous E.T.
*Surfactant Reduces Surface Tension,
Prevents Collapse