A 7 yo comes to GP with low grade fever, fatigue and paroxysmal couch. Has had cold for a week. Coughing has become worse, somtimes leads to vomiting. Temp is 99.8 pulse 82 resp 18 and BP 120/70. Physical exam shows pharyngeal erythema, post nasal drip, mildly enlarged tonsils, soft palpable cervical lymph nodes. Lungs are clear to auscultation. Culturs from naspharyngeal swab reveal gram negative aerobic encapsulated coccobacillus. 1. What is most likely diagnosis? 2. Toxin from this bacteria has what effect on cells? 3. What are stages of this pathology?

The main function of the respiratory system is gas exchange (O2 and CO2). Ventilation is the movement of air through the respiratory tract into (inspiration) and out of (expiration) the respiratory zone (lungs).