I. Function: air distributor, gas exchanger; filters, warms, humidifies air. provides O2 to cells for cellular respiration, gets rid of CO2 waste

II. Respiration

A. Process of exchanging gases between atmosphere and body cells.

B. Breathing

III. Organs

A. Nose

1. External portion

2. Internal portion

3. Vestibule

4. Paranasal sinuses

5. Movement of air through nose: anterior nares (nostrils), vestibule, inferior, middle, superior meati, posterior nares.

B. Pharynx

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

4. Seven openings

5. Functions

C. Larynx

1. Structure

a. False vocal cords

b. True vocal cords

c. Glottis

2. Cartilages

a. Thyroid cartilage

b. Epiglottis

c. Cricoid cartilage

d. Arytenoid cartilages

e. Corniculate cartilages

f. Cuneiform cartilages

3. Functions: passageway for air moving in and out of trachea. protects airway from entrance of solids and liquids during swallowing, voice production.

D. Trachea

1. Location: in front of esophagus, splits into left and right bronchi.

2. Structure: smooth muscle supported by C shaped cartilage rings.

3. Function: traps and removes foreign particles. passageway to lungs.

E. Bronchial tree

1. Primary bronchi

2. Secondary bronchi

3. Tertiary bronchi

4. Bronchioles

5. Alveolar ducts

6. Alveolar sacs

7. Alveoli

F. Lungs

1. Visceral pleura

2. Parietal pleura

3. Pleural cavity

4. Right lung

5. Left lung

6. Functions in air distribution, gas exchange

G. Thorax

1. Structure: parietal layer of pleura lines cavity, adheres to inferior surface of ribs and superior surface of diaphragm.

2. Function: becomes larger when chest is raised, smaller when lowered.

IV. Breathing Mechanism

A. Inspiration

1. Air moves in due to atmospheric pressure.

2. Pressure inside the lungs and alveoli decreases when diaphragm contracts outside air rushes into airways as alveolar pressure drops

3. Lungs expand.

B. Expiration

1. elastic recoil responsible for normal expiration.

2. abdominal organs spring back into previous shapes

3. alveoli decrease in diameter. forcing air out through passageways.

V. Lung Capacity

A. tidal volume: 500 cc enters lungs in normal quiet inspiration.

B. inspiratory reserve volume: quantity of air in addition to tidal volume entering lungs during forced inspiration (3000 cc)

C. expiratory reserve volume: quantity expelled during forced expiration in addition to tidal volume (1100 cc)

D. residual volume: air remaining in lungs after most forceful expiration (1200 cc)

E. vital capacity: total amount of air that can be exhaled after taking deepest breath possible (4600 cc) (insp. reserve + tidal volume + exp. reserve)

F. inspiratory capacity: maximum volume of air a person can inhale following exhalation of tidal volume (3500 cc) (insp. reserve + tidal volume)

G. functional residual capacity: volume of air that remains in lungs following exhalation of tidal volume. (2300 cc) (exp. reserve + residual volume)

H. total lung capacity: (5800 cc) (vital capacity + residual volume)

anatomy page