A 19 year old man comes to GP due to seven day history of weakness, malaise and a dry cough. Temp is 100.0 and broncho alveolar lavage is performed. Washings show slow growing organism on sterol containing media. Lab studies of serum show presence of cold agglutinins. 1. What is most likely causal organism and why? 2. What is common treatment? 3. Why do beta lactams not work?

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).