one of several charts used in testing visual acuity. Letters, numbers, or symbols are arranged on the chart in decreasing size from top to bottom. A wall chart developed by a Dutch ophthalmologist Hermann Snellen in the 19th century, which is still used today to measure visual acuity.
Popliteal Nodes. The popliteal nodes, or popliteal lymph nodes, include six or seven nodes and are located in the legs near the knees at the popliteal fossa.They service the lower legs and feet for the lymphatic system.opliteal Nodes. The popliteal nodes, or popliteal lymph nodes, include six or seven nodes and are located in the legs near the knees at the popliteal fossa.
Lymph nodes are located in groups, and each group drains a specific area of your body. You may be more likely to notice swelling in certain areas, such as in the lymph nodes in your neck, under your chin, in your armpits and in your groin.The site of the swollen lymph nodes may help identify the underlying cause.ymph nodes are located in groups, and each group drains a specific area of your body. You may be more likely to notice swelling in certain areas, such as in the lymph nodes in your neck, under your chin, in your armpits and in your groin. The site of the swollen lymph nodes may help identify the underlying cause.