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.
K) Lymph Nodes Of The Head and Neck Welcome Â» Basic Topics Â» Anatomy Â» Focused Anatomy Â» 1: Head and Neck Â» K) Lymph Nodes Of The Head and Neck The lymph nodes of the head and neck are viewed as either anatomical groups or surgical lymph node regions. Superficial Nodes of the Head. The superficial lymph nodes form a ring extending from the chin to the occiput. From anterior to posterior, these are: Submental nodes are located inferior to the mandible, between the anterior bellies of the digastric muscles. The drain lymph from the anterior tongue, the medial inferior lip, the medial inferior gingivae and teeth, and the chin. Efferent lymph vessels pass to the submandibular group or to deep cervical nodes.