Which statement about lymph flow is correct?

• A. Efferent vessels bring lymph to the lymph node; Afferent carry away from the lymph node
• B. Afferent vessels bring lymph to the lymph node; Efferent vessels carry lymph away from the lymph node
• C. Afferent and efferent vessels both bring lymph to the lymph node
• D. Lymph does not pass through lymph nodes

Answer: (B)

Lymph flows into a lymph node through afferent lymphatic vessels and exits via efferent lymphatic vessels. This arrangement lets lymph be filtered by immune cells as it passes through the node, moving from the afferent entry on the outside, through the subcapsular sinus and into the cortical and medullary areas, and finally leaving at the hilum through efferent vessels toward the venous system. So the statement that afferent vessels bring lymph to the lymph node and efferent vessels carry it away is the correct description. The other possibilities contradict this directional flow or imply that lymph bypasses the node, which isn’t accurate.