SYSTEMA LYMPHATICUM Involves lymphatic vessels that convey the lymph from tissues into the venous system; lymphatic cells, tissues and organs that work in the defense system of the body: lymph nodes, follicles, tonsils, spleen, thymus. LYMPHATIC VESSELS begin in the intercellular spaces as blind vasa lymphocapillaria that form rete lymphocapillare. The wall of the capillaries - endothelial cells with intercellular gaps up to 2 µm wide - influx of fluid containing large molecules or particles. Lymph capillaries return to the circulation about 10% of tissue fluid. Lymph capillaries are absent in the epidermis and its derivatives, epithelium, sclera, cornea, lens and vitreous body of the eye, in the CNS, placenta, teeth, bones, bone marrow and hepatic lobules. The lumen of lymph capillaries is larger than that of blood capillaries. Vasa lymphatica (lymphatics) - paired semilunar valves. A lymph vessel conveying lymph to the node – vas afferens (each node receives several afferent vessels). A vessel that leaves the node – vas efferens (only one efferent vessel emerges from the node). Efferent vessels join to form lymphatic trunks – trunci lymphatici. LYMPH is colorless or slightly yellow clear tissue fluid. Tissue fluid of extracellular spaces is produced by the metabolism of cells and filtrated from blood capillaries. Lymph in the intestine contains also nutrients and fats in small globules – chyle. Lymph contains lymphocytes. The flow of lymph is promoted by the pump, function of muscles, changes of intraabdominal pressure and respiratory movements of the thorax. LYMPH NODE (Nodus lymphaticus) is a bean-shaped organ, 1-30 mm, with smooth surface, whitish or grey-pink, located in the connective tissue as a single organ or in groups. Afferent vessels enter the node at its periphery, the efferent vessel leaves the node from the hilum (together with the vein and artery). A tributary region - regional nodes. Capsula – trabeculae – reticulum. Sinuses – subcapsular, peritrabecular, terminal (medullary). Folliculi lymphatici (germ centres – immunoblasts) - cortex. Medulla > hilum. Release of lymphocytes, production of antibodies and other defense mechanisms, filtration of lymph Tonsils – masses of lymphoid tissue - the immunological barrier at the beginning of the respiratory and digestive tracts. Lymphatic follicles - mucous membranes of the respiratory, digestive and urinary tracts. SPLEEN (LIEN, SPLEN) The largest lymphatic organ. Participates in the body’s defense system – proliferation of lymphocytes, immune response - white pulp. Blood reservoir, storing red blood cells and platelets, identifying, removing and destroying expended red blood cells and platelets - red pulp. THYMUS The right and left lobes joined together by a connective tissue, the left lobe – bigger, situated in the superior mediastinum – area interpleuralis superior (thymica). Age changes: 15 g after birth, 30 – 40 g -the 2^nd to 3^rd year, after puberty gradual involution, replaced by adipose tissue in old age. Pink in a newborn child, yellow in adults. Soft, elastic structure, with a lobular surface. Structure: Connective tissue capsula thymi, septa divide the organ into lobuli thymi, reticulum filled by T-lymphocytes. A dense and darker zone at the periphery – cortex, a thin and lighter inner zone – medulla. Functions: Differentiation of lymphocytes in the immuno-competent T-lymphocytes, maintenance of necessary amount of lymphocytes in blood circulation and in peripheral tissues, development and maaintenance of the immune system. Trunci lymphatici: Ductus thoracicus – truncus lumbalis dx. et sin. truncus intestinalis cisterna chyli pars abdominalis, thoracica, cervicalis truncus intercostalis dx. et sin. truncus jugularis sin. truncus subclavius sin. truncus bronchomediastinalis sin. angulus venosus sin. Ductus lymphaticus dexter – truncus jugularis dx. truncus subclavius dx. truncus bronchomediastinalis dx. angulus venosus dx. Nodi lymphatici (nll.): Head nll.occipitales spf. et prof. nll.retroauriculares nll.parotidei spf. et prof. nll.submandibulares nll.submentales All lymphatic vessels from these nodes drain into deep cervical lymph nodes. Neck nll.cervicales anteriores spf. et prof. nll.cervicales laterales spf. et prof.: a) nll.jugulares interni – nl. tonsillaris (Wood) nl. jugulodigastricus (Küttner) nl. juguloomohyoideus b) nll.comitantes n. accessorius (CN XI) c) nll.supraclaviculares (Wirchow) è truncus jugularis Upper extremity Superficial vessels – collectores laterales collectores mediales collectores anteriores (medii) nll.cubitales spf. Deep vessels – arcus lymphaticus palmaris spf. et prof., deep lymphatics accompany blood vessels nll.cubitales prof. Nll.axillares: nll.axillares centrales nll.axillares laterales nll.axillares pectorales (Sorgius) nll.axillares subscapulares nll.axillares apicales (infraclaviculares) è truncus subclavius Thorax nll.pulmonales nll.bronchopulmonales nll.bronchiales nll.tracheobronchiales superiores dx. et sin., inferiores nll.tracheales nll.mediastinales anteriores nll.mediastinales posteriores nll.phrenici superiores nll.parasternales nll.intercostales è truncus bronchomediastinalis Abdomen and pelvis nll.iliaci externi nll.iliaci interni – paravesicales paravaginales parauterini (Bayer) nll.sacrales nll.iliaci communes nll.lumbales è truncus lumbalis nll.coeliaci - gastrici dx. et sin. gastroepiploici dx. et sin. pylorici hepatici pancreaticoduodenales sup. et inf. pancreatici sup. et inf. lienales nll.mesenterici nll.colici nll.mesenterici inferiores è truncus intestinalis Lower extremity Superficial vessels – collectores mediales collectores laterales collectores posteriores nll.poplitei nll.inguinales spf. Deep vessels – accompany blood vessels nll.inguinales prof. (Cloquet – Rosenmüller) è nodi lymphatici iliaci externi DRAINAGE OF THE BREAST Plexus areolaris, plexus subareolaris, plexus circumareolaris. 1. Lateral quadrants - nll. axillares laterales, subscapulares and centrales. 2. Medial quadrants - nll. parasternales. 3. The center of the breast - nll. interpectorales - nll. infraclaviculares and supraclaviculares. 4. The epigastric pathway – along a. epigastrica inf. - anterior mediastinal and hepatic nodes. 5. The intercostal pathway – nll.intercostales. Connections are between lymph vessels of both breasts. DRAINAGE OF THE UTERUS Corpus uteri – nll. lumbales Fundus uteri – along lig. teres uteri – nll. inguinales spf. Cervix uteri – ant. surface – nll. iliaci ext., lat. parts - nll. iliaci int., post.surface – nll. sacrales. Ovary – nll. lumbales Vagina – nll. iliaci int. et ext. External genital organs – nll. inguinales spf. DRAINAGE OF THE TESTIS Nll. lumbales, iliaci ext. (along the deferent duct), inguinales spf. et prof. from external gen. organs.