BIO 12 UNIT 4: Study Notes

RESPIRATORY SYSTEM PARTS FUNCTIONS

1. Larynx: aka the voice box, vocal chords
2. Trachea: aka the windpipe, tube that carries air towards the lungs and out of the body, C shaped rings strengthen the trachea
3. Bronchi: Tubes divergent from the trachea that lead to the left and right lung, go to each lung
4. Bronchioles: further divisions of bronchi, lead to the alveoli 
5. Alveoli: Hollow cavities found within alveolar sacs, very thin walls allow for gas exchange between CO2 and O2 (exchange between lungs and blood), capillaries are prominent with alveoli allowing for these gases to pass (approx. 3 million alveoli in human lung)
6. Diaphragm: Contracts to aid with inhalation (increases thoracic cavity) or relaxes during exhalation
7. Ribs: Protects lungs, moves up and out during inhalation (increases thoracic cavity), opposite during exhalation
8. Pleural Membranes: Membrane that encloses the lungs, outer pleural membrane sticks to ribs and diaphragm; inner membrane sticks to lungs, allows lungs to move freely without friction, helps lungs inflate (expand)
9. Thoracic Cavity: Contains respiratory organs, "lung cavity", size and pressure effects whether inhalation or exhalation occurs