**Question:** Posterior wall of the axilla is formed by all of the following muscles, EXCEPT?

A. Pectoralis Major
B. Latissimus Dorsi
C. Teres Major
D. Teres Minor

**Core Concept:**
The axilla is a region located between the arm and chest, containing various muscles and nerves that contribute to arm movement and sensation. The posterior wall of the axilla refers to the muscles that form the backside of this region.

**Why the Correct Answer is Right:**
The correct answer, **D. Teres Minor**, is excluded from forming the posterior wall of the axilla because it is a muscle of the lateral side of the shoulder joint, not the axilla. The posterior wall is primarily composed of muscles such as Pectoralis Major, Latissimus Dorsi, and Teres Major. Teres Major is located on the lateral aspect of the scapula, while Teres Minor is not relevant to the posterior axillary wall.

**Why Each Wrong Option is Incorrect:**
A. Pectoralis Major (Option A) is a large muscle that contributes to chest expansion and internal rotation of the arm, thus, it is a part of the posterior axillary wall.
B. Latissimus Dorsi (Option B) is a broad muscle that helps in arm extension, abduction, and external rotation. It is also a part of the posterior axillary wall.
C. Teres Major (Option C) is a smaller muscle that assists in internal rotation of the arm and contributes to the posterior axillary wall.

**Clinical Pearl:**
Understanding the anatomy of the axilla and its muscles is crucial for clinical practice, particularly in assessing and treating shoulder and arm injuries or movements. A thorough understanding of these muscles can aid in accurate examination and diagnosis of patients with axillary or proximal arm issues.