8Mechanisms of Breathing DiaphragmContracts and moves downward towards the abdominal cavity when stimulated by the brainVentilationThe combination of inspiration (breathing in) and expiration (breathing out)Tidal VolumeVolume of air in each breathRespiratory FrequencyThe number of breaths taken per minute
9Controlling Ventilation Respiratory Control CentreFound within brain stemMedulla oblongata and pons
10Lung Volumes Static Lung Volume Dynamic Lung Volume Determined by actual structure of lungDynamic Lung VolumeDependent, not only on volume, but on the movement or flow of airThree important Static Lung volumesTotal lung capacity, vital capacity, residual volumeTLC = VC + RV
11Gas Exchange Diffusion The movement of gas, liquid or solid from a region of high concentration to low concentration.
12Oxygen Transport 2% of Oxygen found within plasma of blood Hemoglobin Specialized protein found in erythrocytes that binds to Oxygen
13Carbon Dioxide Transport Small amount is dissolved in the plasma (5 – 10%)90 – 95% of CO2 diffuses into erythrocytes, passed to alveoli and is exhaled
14Ventilation and pHBlood pH is a measure of how acidic and basic blood isBlood pH is close to 7.4 – neutral is 7More acidic during exercise – lactic acid (decreased pH)Ventilation increase pH back to normal