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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Normal intrapleural pressure at the sta/beginning of inspiration is----- cm of H2O.
assistant
The correct answer is  During inspiration, the diaphragm and external intercostal muscles contract, increasing the volume of the thoracic cavity. This causes the intrapleural pressure to become more negative, which increases the transpulmonary pressure, causing the lungs to expand Ref: guyton and hall textbook of medical physiology 12 edition page number:316,317,318