The umbilicus (transumbilical plane) serves as a dividing line for superficial lymphatics. Superior to the umbilicus, lymph drains to axillary nodes. Inferior to the umbilicus lymph drains to the superficial inguinal nodes. The breast is divided into four quadrants. The lateral two quadrants drain into axillary lymph nodes and the medial two quadrants drain into mediastinal lymph nodes.

What are the functions of lymph nodes?

The patient’s slide exhibits numerous structures seen at label A. What is this structure and how did it form?

What region of the lymph node is letter B located in?