Posterior wall of axilla is formed by all EXCEPT:
**Core Concept**
The posterior wall of the axilla is formed by the scapula, subscapularis muscle, and teres major muscle, which provide structural support to the region and help to separate it from the chest cavity.
**Why the Correct Answer is Right**
The correct answer is related to the anatomical boundaries of the axilla. The posterior wall of the axilla is primarily formed by the scapula and the muscles attached to it, including the subscapularis and teres major muscles. These structures help to create a distinct boundary between the axilla and the posterior chest wall.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, so we proceed to the next option.
* **Option B:** This option is not relevant to the posterior wall of the axilla.
* **Option C:** This option might be a distractor, but it is not directly related to the posterior wall of the axilla.
* **Option D:** This option is not relevant to the posterior wall of the axilla.
**Clinical Pearl / High-Yield Fact**
When examining the axilla, it's essential to note the boundaries formed by the scapula and its attached muscles, which can help in identifying anatomical abnormalities or pathologies in the region.
**Correct Answer: B.**