The Lymphatic System

Transcription

1 The Lymphatic System 1. The lymphatic system an overview 2. Structure of the lymphatic vessels 3. The major lymphatic vessels 4. Structure of lymph nodes 5. Regional lymph nodes 6. Hematopoietic and lymphopoietic organs

2 The lymphatic system The lymphatic system, systema lymphaticum: integral part of the circulatory system synonym: immune system provides the immune response composed of: lymph vessels lymph lymph organs 2

3 The lymphatic system lymph vessels and nodes hemopoietic and lymphatic organs central lymphoid tissue peripheral lymphoid tissue 3

4 Structural plan of lymph vessels Lymphatic capillaries: single layer of endothelium incomplete basal lamina, no pericytes Small lymphatic vessels: presence of internal valves elastic and collagen fibers around the endothelium single muscle cells Large lymphatic vessels >0.2 mm tunica intima endothelium longitudinal elastic fibers tunica media 1-3 layers of muscle cells tunica adventitia collagen and elastic fibers longitudinal muscle cells 4

5 Lymphatic vessels, vasa lymphatica The major lymphatic vessels: lymph ducts, ducti lymphatici lymph trunks, trunci lymphatici The lymphatic capillaries 5

6 The lymph trunks Unpaired lymph trunks: intestinal trunk, truncus intestinalis Paired lymph trunks: lumbar trunk, truncus lumbalis bronchomediastinaltrunk, truncus bronchomediastinalis subclavian trunk, truncus subclavius jugular trunk, truncus jugularis 6

7 The cisterna chyli angulus venosus sinister ductus thoracicus cisternachyli Th 11 -L 2 truncus intestinalis trunci lumbales 7

8 The main lymphatic vessels The thoracic duct, ductus thoracicus angulus venosus sinister: length cm; diameter 5 mm passes through hiatus aorticus before opening it joints: truncus subclavius sinister truncus jugularis sinister truncus bronchomediastinalis sinister collects the lymph from the: left side of the head and neck left upper limb left half of the thoracic cavity organsinabdominalcavityanditswall pelvis lower limbs rich in valves well-developed smooth musculature own blood vessels 8

9 The main lymphatic vessels The right lymphatic duct, ductus lymphaticus dexter angulus venosus dexter (v. subclavia dextra) variable: length mm; diameter 2 mm has two valves at its orifice before opening it joints: truncus subclavius dexter truncus jugularis dexter truncus bronchomediastinalis dexter collects the lymph from the: right side of the head and neck right upper limb right half of the thoracic cavity 9

10 Structure of lymph nodes The lymph nodes, nodi lymphatici (lymphonodi): in groups or rows along the lymphatic vessels regional lymph nodes Major functions: mechanical filters of the lymph phagocytosis production of antibodies house Т-lymphocytes lymphopoiesis Morphological characteristics: size 2-20 mm shape highly variable, usually ovoid or bean-shaped Macroscopic anatomy: the capsule, capsula trabeculae hilum vasa lymphatica afferentia vasa lymphatica efferentia 10

11 Microscopic anatomy Histological structure: reticular supporting elements reticular(collagen type ІІІ) fibers reticulum cells fibroblasts macrophages dendritic cells antigen-presenting cells follicular dendritic cells Theparenchymaofthelymphnode three zones: the cortex, cortex paracortical region, paracortex inner medulla, medulla 11

12 Microscopic structure The cortex, cortex B-cell zone: lymphatic follicles with or without germinal centers arranged in layers The paracortical zone, paracortex, deep cortex thymus-dependent zone: Langerhans cells dendritic cells high endothelial venules Medullary region, medulla: anastomosing cords of lymphoid tissue B-lymphocytes plasma cells T-lymphocytes macrophages 12

13 Microscopic structure Lymphatic sinuses: marginal (subcapsular) sinuses, sinus subcapsulares afferent lymph vessels intermediary (cortical) sinuses, sinus corticales perinodulares medullary sinuses, sinus medullares hilar sinuses afferent lymph vessels Sinus wall: mantle (littoral) cells role of endothelial macrophages Sinus spaces: free macrophages lymphocytes monocytes plasma cells The angioarchitectonics 13

14 The lymphatic drainage of the head and neck 14

15 The lymph nodes of the head 15

16 Lymphatic drainage of the neck The lymph nodes of the neck: nodi supraclaviculares nodi cervicales anteriores: superificial deep pharynx, larynx, thyroid gland nodi cervicales laterales: superficial deep: nodus jugulodigastricus nodus juguloomohyoideus 16

17 The lymphatic drainage of the upper limbs 17

18 The lymph nodes of the upper limb Nodi lymphoidei cubitales: 1-3 isolated nodes: around the large blood vessels subcutaneously above the medial epicondyle Nodi lymphoidei axillares: five groups (15-40): apical group: 6-10 central group: 4-6 lateral group: 3-8 pectoral group: 3-8 subscapular group: 3-6 subcutaneously, subfascially around the blood vessels 18

19 The lymphatic drainage of the upper limb Superficial vessels: internal group: along the basilic vein nodi lymphoidei cubitales external group: run parallel with the cephalic vein nodi lymphoidei axillares Deep vessels along the course of the large arterial vessels: radial artery ulnar artery cubital lymph nodes brachial artery axillary lymph nodes 19

20 The lymphatic drainage of the thorax 20

21 The lymph nodes of the thoracic wall and deeper tissues The parietal lymph nodes: nodi parasternales nodi intercostales The visceral lymph nodes: nodi intrapulmonales nodi bronchopulmonares nodi tracheobronchiales nodi paratracheales nodi juxtaesophageales nodi prepericardiaci 21

22 The lymphatic drainage of the abdomen 22

23 The parietal lymph nodes The lumbar (pre-aortic, lateral aortic right and left, and retro-aortic) lymph nodes (nodi lumbales): lymph nodes around the abdominal aorta and the inferior vena cava Thecommoniliaclymphnodes (nodi iliaci communes) 23

24 The visceral lymph nodes the coeliac lymph nodes, nodi coeliaci the gastric lymph nodes: nodi gastrici dextri nodi gastrici sinistri nodi pylorici the hepatic and cystic lymph nodes the pancreaticosplenic lymph nodes small nodes the lymph nodes of the colon: four groups along the vessels the lymph nodes of the mesentery: (300) nodes hilar nodes in the mesentery 24

25 The lymphatic drainage of the pelvis 25

26 The lymph nodes of the pelvis the external iliac lymph nodes the internal iliac nodes: 9-12 the sacral lymph nodes the anorectal lymph nodes 26

27 The lymphatic drainage of the lower limbs 27

28 The lymphatic vessels of the lower limb The superficial lymph vessels: the vessels of the medial group: along the great saphenous vein the superficial inguinal lymph nodes nodes the vessels of the postero-lateral group run parallel to the small saphenous vein end in the popliteal lymph nodes The deep lymph vessels accompany the main blood vessels of the limb: anterior tibial artery posterior tibial artery popliteal lymph nodes femoral artery and vein deep inguinal lymph nodes 28

29 The lymph nodes of the lower limb Nodi inguinales superficiales: 12-16: around hiatus saphenus parallel to the inguinal fold Nodi inguinales profundi: 3-5 nodes: in fossa ileopectinea over the femoral vein Nodi poplitei: 4-6 nodes: in fossa politea around the popliteal artery and vein Nodus tibialis anterior: over membrana interossea cruris 29

30 Lymph node inflammation sites 30

31 The cardinal signs of inflammation 31

32 Clinical manifestations lymphadenitis lymphangitis 32

33 The lymphoid organs The lymphopoietic organs, organa lymphopoetica: primary lymphatic organs: bone marrow thymus secondary lymphatic organs: lymph nodes spleen diffuse lymphoid tissue, tonsils, MALT, GALT and BALT 33

34 Hematopoietic organs The bone marrow, medulla ossium: red bone marrow, medulla ossium rubra epiphyses of the long bones, spongy bone of the short and flat bones, ~ 1500 g haematopoiesis biological defense yellow (fatty) bone marrow, medulla ossium flava medullary canal of long bones a reserve haematopoietic organ 34

35 The red bone marrow Microscopic structure: connective tissue stroma reticular fibers adventitial (reticular) cells macrophages lipocytes (adipocytes) osteoblasts marrow parenchyme stem cells erythroblasts myeloblasts and myelocytes megakaryocytes venous sinusoids 35

36 The thymus, thymus The thymus, thymus (Gr. θύμος, θυμάρι, the herb thyme): differentiation of T-lymphocytes a true endocrine gland Embryonic origin: endodermal derivative 3 rd &4 th pharyngealpouches Postnatal growth: maximum relative weight 2 years slow age involution after puberty residual thymus in the elderly adipose thymus organ 36

37 Thymus location Location and somatotopy: in anterior mediastinum trigonum thymicum behind sternum, anterior to the heart and great vessels External appearance: right and left lobes shape variable, an irregular cone weight ~15 g (at birth); g (at puberty) size at birth: length 5 mm width 4 mm thickness 6 mm color: in children pinkish grey in adults yellowish soft and finely lobulated 37

38 Structure of the thymus Macroscopic anatomy: thin connective tissue capsule trabeculae (septa), septa interlobularia pseudolobular structure, lobuli thymi The structure of a thymus lobule: peripheral cortex, cortex thymi central medulla, medulla thymi 38

39 Microscopic anatomy Histological structure: cortex darkly stained, densely cellular: does not possess lymphoid nodules rich in compact lymphoid tissue small lymphocytes, thymocytes (Т-lymphocyte precursors) epithelial reticular cells thymic nurse cells macrophages reticular fibers not present medulla lightly stained 39

40 Microscopic anatomy Histological structure: thymic medulla: epithelial reticular cells antigen-presenting large dendritic cells differentiated Т-lymphocytes immunocompetent Т-lymphocytes Т-helpers humoral immunity Т-killers cell-mediated immunity suppressor Т amplifier Т cells thymic (Hassall) corpuscles epithelial reticular cells in degeneration 40

41 The spleen, splen The spleen, splen (Lat. lien): the largest lymphoid organ in the human body an unpaired organ of the immune and circulatory systems Location in abdomen: in left upper part of abdominal cavity between the 9 th and 11 th ribs longitudinal axis follows the 10 th rib Main functions: immunological protection role in the production of antibodies production of activated lymphocytes destruction of erythrocytes and platelets (thrombocytes) mechanical blood filtration reservoir of blood 41

42 External features: Macroscopic anatomy typically coffee bean shaped weight g the size of a clenched fist length ~11 cm width 6-8 cm thickness up to 4 cm color reddish purple; soft tissue 42

43 Macroscopic anatomy General structure: anterior extremity posterior extremity superior border inferior border diaphragmatic surface convex and smooth visceral surface splenic (lienal) hilum splenic artery and vein efferent lymphatic vessels postgangionic sympathetic fibers gastric impression colic impression pancreatic impression renal impression 43

44 Microscopic anatomy Histological structure: serous coat, tunica serosa gastrosplenic ligament phrenicosplenic ligament fibro-elastic coat (capsule), tunica fibrosa splenic trabeculae collagenous fibrous tissue, abundant elastic fibers and a few myofibroblasts the trabecular blood vessels The parenchyme, pulpa splenica: white pulp, pulpa alba red pulp, pulpa rubra 44

45 Histological structure The white pulp, pulpa alba: compact lymphoid tissue folliculi lymphatici splenici, splenic lymph follicles (Malpighian corpuscles) rich in В-lymphocytes Periarterial Lymphatic Sheath (PALS) Т-cell region marginal zone sinusoids 45

46 Histological structure The red pulp, pulpa rubra: splenic or venous sinuses (sinusoids) endotheliocyti fusiformes 2-3 µm gaps fibrae reticulares annulares afferent and efferent sphincters splenic cords (of Billroth), chordae splenicae loose meshwork of reticular fibers reticular cells,т-andв-lymphocytes, macrophages, plasma cells and numerous blood cells (Er, Leu and Thr) 46

47 Histological structure The red pulp, pulpa rubra: splenic or venous sinuses (sinusoids) endotheliocyti fusiformes 2-3 µm gaps fibrae reticulares annulares afferent and efferent sphincters splenic cords (of Billroth), chordae splenicae loose meshwork of reticular fibers reticular cells,т-andв-lymphocytes, macrophages, plasma cells and numerous blood cells (Er, Leu and Thr) 47

48 Thank you... 48