Lab 1 Module 3: Posterior Triangle of the Neck - Page 5 of 5

CASE REPORT CONCLUSION:

When performing a complete axillary lymph node dissection there are several nerves that are more at risk than the other nerves of the region... these nerves were covered in other courses.

The Long Thoracic Nerve arises from ventral rami of C5, C6, C7 and passes posterior to the trunks of the brachial plexus and courses along the superficial surface of the serratus anterior muscle (part of the medial wall of the axilla). This nerve innervates the serratus anterior, which functions to protract the scapula and hold it against the thoracic wall. This nerve was previously identified. Find it on the 3D model.

If the long thoracic nerve were lacerated, what would happen to the scapula?

The Thoracodorsal Nerve (also known as the middle subscapular nerve) branches from the posterior cord of the brachial plexus (C6-C8). It descends along the posterior wall of the axilla to innervate the latissimus dorsi muscle. The latissimus dorsi is a powerful adductor, extenser, and medial rotator of the arm at the glenohumeral joint. Injury to the thoracodorsal nerve results in weakness of these shoulder movements, particularly when performing activities like swimming or climbing. This nerve was previously identified. Find it on the 3D model.

The Intercostobrachial Nerve is a cutaneous branch of the second intercostal nerve (T2). It exits the thoracic wall, crosses the axilla, and joins the medial brachial cutaneous nerve to provide sensory innervation to the skin of the medial arm and axilla. During axillary or breast surgery, this nerve is particularly vulnerable, and injury may cause postoperative pain or numbness in the proximomedial arm (This nerve is not visible on this 3D model).