Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. In eudicots, pith is located in the center of the stem. In monocots, it extends also into flowering stems and roots. The pith is encircled by a ring of xylem; the xylem, in turn, is encircled by a ring of phloem.
Throughout the lymph node's interior are a series of street-like channels called sinuses that help guide the flow of lymph from the afferent lymphatic vessels, through the cortex and medulla, and finally to the efferent lymphatic vessels at the hilum.ach lymph node chain is responsible for draining a particular body region or structure. For example, the lymph node chains in your armpits drain your arms and upper chest, while the chains in your groin are responsible for filtering lymph from your feet, legs, genitals, and lower abdominal wall.
The epitrochlear lymph nodes, also known as the cubital or supraepitrochlear lymph nodes, are part of the superficial lymphatic system of the upper limb. There are usually one or two of these lymph nodes, sometimes three, and rarely four.The epitrochlear nodes are located in the subcutaneous connective tissue on the medial aspect of the elbow, about 4â5 cm above the humeral epitrochlea.evertheless, drainage areas of the upper limb are characterized by wide interindividual variability. Some lymphatic vessels arise from the epitrochlear nodes and extend to the axillary station [1] (Fig. 1). Fig. 1. Normal epitrochlear lymph node.