This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Function of external intercostal - \nSelect and explain. \nA. Elevation of ribs, B. Expiration, C. Depression of ribs, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Elevation of ribs Actions of intercostal muscleso The main action of the intercostal muscles is to prevent intercostal spaces being drawn in during inspiration and bulging outwards during expiration.o The external intercostals, interchondral portions of the internal intercostals and the levator costae may elevate the ribs during inspiration.o The internal intercostals except for the interchondral portions and the transversus thoracis may depress the ribs or cartilages during expiration.", 'role': 'assistant'}]