**Question:** All of the following are branches from the CORDS of brachial plexus EXCEPT:

A. Radial Nerve
B. Intercostal Nerve
C. Suprascapular Nerve
D. Subclavian Artery

**Correct Answer:** D. Subclavian Artery

**Core Concept:** The brachial plexus is a complex network of nerves formed by the union of the ventral rami of C5-C8 and T1 spinal nerves. It is located in the posterior mediastinum and sends branches to the upper extremity. The brachial plexus has several important nerves that arise from it, which are collectively known as CORDS. These nerves are:

- C5 and C6: Anterior Circle
- C7: Posterior Circle
- C8 and T1: Teres Minor and Major Circle

**Why the Correct Answer is Right:** Subclavian artery is an arterial structure, not a nerve. It is a major blood vessel that arises from the thoracic aorta and supplies blood to the upper limb. The CORDS nerves from the brachial plexus are involved in the sensory, motor, and sympathetic innervation of the upper limb.

**Why Each Wrong Option is Incorrect:**

A. Radial Nerve (C8 and T1): This nerve is a branch of the brachial plexus and is essential for the motor innervation of the radial side of the forearm and hand.

B. Intercostal Nerve (C5-C8): This nerve is a branch of the spinal nerves that innervate the intercostal muscles and skin of the anterior chest wall. It is not a part of the CORDS from the brachial plexus.

C. Suprascapular Nerve (C4-C5): This nerve is a branch of the brachial plexus and is responsible for the motor innervation of the supraspinatus and infraspinatus muscles, which are important for shoulder movements. It is a valid branch of the brachial plexus but not a part of the CORDS.

**Clinical Pearls and Pearls:**

1. Understanding the anatomy of the brachial plexus and its branches is crucial for interpreting clinical findings in patients presenting with upper limb symptoms.
2. The CORDS (C8, T1, radial, and axillary nerves) are the main branches responsible for sensory, motor, and sympathetic innervation to the upper limb. Recognizing these nerves and their functions is essential for proper diagnosis and management of upper limb disorders.
3. The brachial plexus is important for understanding the anatomy of the upper limb and its innervation. This knowledge is vital for diagnosing and treating upper limb issues in clinical practice.