Lymphatic & Immune / VISUAL EXPLAINER
Do Lymphocytes Enter a Lymph Node Only with Lymph?
Many circulating lymphocytes enter lymph nodes from blood through specialized high endothelial venules in the paracortex. This entry into node tissue differs from lymph arriving through afferent lymphatic vessels; blood and lymph are not one open conduit.
READ THE IMAGE
What the illustration shows
Cream-and-gold poster titled A blood entrance to the lymph node. A small lymph-node cutaway labels an afferent lymphatic, subcapsular sinus, outer cortical follicles, paracortex and blood vessels at the hilum. A magnified paracortical window shows a high endothelial venule lined with plump pink cells. Red blood cells remain in its lumen; purple lymphocytes occupy the lumen and surrounding tissue, with one elongated purple cell crossing the lining. Labels identify blood lumen, tall endothelial cells and a lymphocyte entering tissue. A lower comparison contrasts tall HEV lining with thin ordinary venule lining. Text distinguishes blood entry from lymph arrival and notes representative cell crossing and varied schematic scales. Gold AllHumanBody.com and the complete slogan are at the bottom.
How to interpret this poster
- Locator architecture, cell sizes and endothelial thickness vary in scale and are not a complete node section or measured histology.
- One representative crossing is not a permanent hole, an exclusive mechanism or a universal fraction.
- No claim every lymphocyte uses HEVs, entry requires infection or crossing guarantees activation; no swelling diagnosis or immune-strength promise.
- AI-assisted educational illustration; not physician certification, microscopy, a diagnosis or individualized medical advice.
- Fine annotations need enlargement; the full description provides an accessible text alternative.
- Display the full uncropped illustration; do not trim titles, legends or boundary annotations.
AI-assisted educational illustration, adapted into web-sized images without changing its composition. This is general education, not an individual diagnosis or treatment recommendation.
EVIDENCE / CONTEXT
Sources and what they support
- University of Leeds: Lymph nodes ↗
Paracortical HEV blood entry and tall endothelial lining.
- Histology Guide: MH 076–078 — Lymph Node ↗
Human lymph-node teaching text identifies paracortical HEVs.