In a stab wound to the back at the level of the 7th intercostal space in the midscapular line on the right side, which structures are encountered in sequence from superficial to deep before reaching the pleural cavity?

• A Skin → trapezius → serratus posterior inferior → intercostal muscles → parietal pleura
• B Skin → latissimus dorsi → serratus posterior inferior → external intercostal → internal intercostal → innermost intercostal → parietal pleura ✓
• C Skin → latissimus dorsi → serratus anterior → intercostal muscles → parietal pleura
• D Skin → trapezius → rhomboid major → intercostals → endothoracic fascia → parietal pleura

Explanation

In the midscapular line posteriorly at the 7th intercostal space, the layers encountered are: skin and subcutaneous tissue → latissimus dorsi → serratus posterior inferior → external intercostal muscle → internal intercostal muscle → innermost intercostal muscle → endothoracic fascia → parietal pleura. Trapezius covers only the upper back medially; it is not present at the 7th intercostal space in the midscapular line. Rhomboids lie more medially near the spine. This sequence is tested in chest drain/thoracocentesis anatomy.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.