General Info Delivers O2 to the body; disposes of CO2 Works with circulatory system Thoracic cavity: surrounded by ribs and diaphragm

Nose External nares (nostrils) - Lined with mucus on a superficial network of veins Nasal cavity: interior of nose Surrounded by paranasal sinuseslighten skull, resonance chambers for speech, produce mucus. Infection of the nose can spread to the sinuses = sinusitis (blocked passageways between nasal cavity and sinus = partial vacuum and causes a sinus headache) Surrounded by paranasal sinuses: lighten skull, resonance chambers for speech, produce mucus. Infection of the nose can spread to the sinuses = sinusitis (blocked passageways between nasal cavity and sinus = partial vacuum and causes a sinus headache)

Cilia create a gentle current that moves contaminated mucus down the throat where it is swallowed and digested by the stomach Cold weather slows cilia

Pharynx (throat) Passageway for food AND air muscular Pharyngeal tonsils

Auditory tubes drain ear here which is why an ear infection sometimes follows a sore throat. Pharyngeal tonsils get swollen and block nasopharynx and person breathes through mouth  mouth breathing is not properly moistened, warmed or filtered

Larynx (voicebox) cartilage Contains vocal cords – vibrate when air passes over Epiglottis -tilts when swallowing, blocking the opening of the larynx

Trachea Lined with ciliated mucosa – cilia moves foreign material AWAY from the lungs. Smoking destroys cilia

Primary bronchi Division of trachea

Lungs Left = 2 lobes; right = 3 lobes Bronchi subdivide into secondary, tertiary bronchi Ends with bronchioles Lead into alveoli (air sacs)  place of gas exchange

enlarged

SUMMARY Thoracic cavity surrounded by rib cage and diaphragm Pulmonary arteries (2) go to the lungs to unload CO2 Pulmonary veins (4) bring oxygenated blood back to heart Ciliated cells line respiratory track. WHY? Mucus lines respiratory track. WHY? Most organs of respiratory track are passageways for air. WHAT’S THE EXCEPTION?

A smoker’s lungs

Pulmonary (or visceral) pleura: surrounds each lung. Parietal pleura line the thoracic cavity These membranes produce pleural fluid These membranes produce pleural fluid Pleura