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.
Radiation is given to reduce the risk of the cancer coming back in the breast area and nearby tissue (doctors call this loco-regional recurrence). Doctors sometimes also recommend that lymph nodes near the area where the breast cancer was removed be included in the area that gets radiation.This is called regional lymph node radiation. Regional lymph node radiation may include the internal mammary lymph nodes, which are the nodes underneath the chest wall.adiation is given to reduce the risk of the cancer coming back in the breast area and nearby tissue (doctors call this loco-regional recurrence). Doctors sometimes also recommend that lymph nodes near the area where the breast cancer was removed be included in the area that gets radiation.