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.
1 Popliteal artery: A branch of the femoral artery, the popliteal artery branches further to supply blood to the knee, thigh, and calf. 2  It ends at the anterior and posterior tibial arteries. 3  Posterior tibial artery: This branch of the popliteal artery supplies oxygenated blood to the leg and sole of the foot.n Depth: Vessels. Once blood is oxygenated in the lungs, it returns to the heart and is then pumped throughout the body. A web of blood vesselsâarteries, veins, and capillariesâcirculate blood to organs, muscles, bones, and other tissues.