The upper horizontal watershed separates the neck and shoulder territory from the territories of the arm and thorax.

• A. Cannot determine
• B. Not applicable
• C. True
• D. False

Answer: (C)

In manual lymph drainage, the body is divided into drainage territories separated by watershed lines. The upper horizontal watershed marks the boundary between the neck/shoulder drainage zone and the arm/thorax drainage zone. Lymph from the neck and shoulder tends to drain toward cervical/supraclavicular nodes, while lymph from the arm and chest drains toward axillary and parasternal nodes. So this boundary correctly delineates two distinct drainage paths. In practice, you direct strokes toward the regional nodes corresponding to the territory you're treating, moving lymph toward the appropriate node groups and respecting this boundary. Therefore, the statement is true.