Lymphology Association of North America (LANA) Practice Exam

Where are the lymphatic capillaries of the skin located?

1. Directly under the epidermis

2. In the sub-fascia

3. Directly above the epidermis

4. In the subcutaneous tissue

The correct answer is: Directly under the epidermis

Lymphatic capillaries in the skin are indeed located directly under the epidermis. This positioning allows them to effectively collect interstitial fluid that is filtered out of capillaries within the dermis and return it to the lymphatic system. The close proximity to the epidermis is crucial, as it enables lymphatic capillaries to respond to changes in the skin, such as inflammation or injury, by transporting excess fluid, proteins, and potentially pathogens away from the tissue. Understanding this location is important because it highlights the role of lymphatic capillaries in maintaining tissue homeostasis and their involvement in immune response. Their structure is also unique, featuring overlapping endothelial cells that create one-way valves to ensure unidirectional flow, which aids in the prevention of fluid accumulation in the skin. This anatomical feature is vital for practitioners to recognize when assessing conditions related to lymphedema or other lymphatic disorders.