This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: Physiology
[{'content': 'Transthoracic compliance formula:- \nSelect and explain. \nA. C = Vt x RR /PEEP, B. C = V/AIv p - atmospheric pressure, C. C = Vt/Pplt - PEEP, D. C = Vt/Pk - Pplt', 'role': 'user'}, {'content': "Answer: B \nExplanation: Various pressures in thoracic cage. 1. Intra pleural pressure - - Intra pleural pressure is the pressure of the fluid in the thin space b/w the lung pleura & the chest wall pleura - It's a slight negative pressure. - Normal pleural pressure at the beginning of inspiration is about - -5 cm H2O (at rest) - At rest - - 5cm H2O - At normal inspiration - - 7.5 cm H2O 2. Intra alveolar pressure - Pressure in alveolus - This is equal to atmospheric pressure. - It is considered to be zero at rest. Transpulmonary pressure - difference b/w alveolar & pleural pressure. Transthoracic pressure - Transthoracic compliance - Alveolar pressure - Atmospheric pressure", 'role': 'assistant'}]