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
Attachment of the first rib is all except 
Select and explain. 
A. Scalenus posterior, B. Scalenus anterior, C. Scalenus medius, D. Parietal pleura
A: Scalenus posterior
Answer: A: Scalenus posterior 
Explanation: The first rib has several attachments which are listed below; Anterior scalene muscle: scalene tubercle Middle scalene muscle: between groove for the subclan aery and transverse tubercle Intercostal muscles: from the outer border Subclavius muscle: arises from the distal shaft and first costal cailage First digitation of the serratus anterior muscle Parietal pleura: from the inner border Costoclavicular ligament: anterior to the groove for the subclan vein Ref -<a href="