Which superficial muscle covers a large part of the posterior thorax?

• A. Latissimus dorsi
• B. Biceps brachii
• C. Rectus abdominis
• D. Pectoralis major

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by identifying the anatomical location described in the question. The posterior thorax refers to the back side of the chest region.
2. Step 2: Review the functions and locations of the muscles listed in the options. For example, the latissimus dorsi is a large, flat muscle that spans the lower back and extends to the posterior thorax.
3. Step 3: Compare the latissimus dorsi to the other options. The biceps brachii is located in the anterior arm, the rectus abdominis is part of the abdominal wall, and the pectoralis major is located in the anterior chest.
4. Step 4: Understand that the latissimus dorsi is the only muscle among the options that covers a significant portion of the posterior thorax. It plays a role in movements such as arm extension, adduction, and internal rotation.
5. Step 5: Conclude that the correct answer is latissimus dorsi based on its anatomical location and function, as it matches the description provided in the question.