**Question:** Clavipectoral fascia is pierced by all of the following structures, EXCEPT?

A. Subclavian artery
B. Subclavian vein
C. Brachial artery
D. Thoracic duct

**Core Concept:** The clavipectoral fascia is a thin layer of fascia that lies between the clavicle and the pectoralis major muscle. It is pierced by various structures, including arteries, veins, and a lymphatic vessel.

**Why the Correct Answer is Right:** The correct answer, **D. Thoracic duct**, is excluded because it is a lymphatic vessel, and the clavipectoral fascia is not designed to allow the passage of lymphatic vessels. The other options are arteries (A and C) and a vein (B), which are all part of the brachial plexus and typically pass through the fascia without any issues.

**Why Each Wrong Option is Incorrect:**

A. **Subclavian artery** is a major artery supplying blood to the upper extremity and is part of the brachial plexus. The clavipectoral fascia is a common site for this artery to pierce through.

B. **Subclavian vein** is another major vein in the upper limb and is also part of the brachial plexus. Similar to the subclavian artery, the clavipectoral fascia is a common site for this vein to pierce through.

C. **Brachial artery** is another artery supplying blood to the upper extremity and is part of the brachial plexus. The clavipectoral fascia is a common site for this artery to pierce through.

**Clinical Pearl:** The clavipectoral fascia provides a common route for several structures, including arteries (subclavian and brachial arteries) and veins (subclavian and brachial veins), to pass through while supplying blood to the upper limb in the brachial plexus. Understanding the anatomy of the clavipectoral fascia is essential for surgeons, anesthesiologists, and radiologists who work with this region.