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.
Anatomy The mediastinal lymph nodes are located in the region of the thoracic cavity between the lungs known as the mediastinum. There are two major groups of mediastinal lymph nodes: the anterior and posterior nodes.The anterior mediastinal lymph nodes are located posterior to the sternum and anterior to the heart.... Click to read more below. The mediastinal nodes are a group of lymph nodes located in the thoracic cavity of the body.These nodes play an important role in the filtration of lymph before it is returned to circulatory system.here are two major groups of mediastinal lymph nodes: the anterior and posterior nodes. The anterior mediastinal lymph nodes are located posterior to the sternum and anterior to the heart.... Click to read more below. The mediastinal nodes are a group of lymph nodes located in the thoracic cavity of the body.