1、淋巴系統解剖第1頁，共15頁，2022年，5月20日，12點49分，星期四Overview of the Lymphatic SystemIncludes, vessels, fluid, and nodes or nonsecreting glands. Lymphatic vessels convey fluid from the periphery to the veins. The fluid, lymph (=clear spring water), is what seeps out of the blood at the peripheral capillaries. Compo

2、sition is similar to plasma without the proteinsLymphatic organs or tissues (glands) are filtering areas and arenas of lymphocyte maturation and competency.第2頁，共15頁，2022年，5月20日，12點49分，星期四Major Functions of Lymphatic SystemFiltration of lymphReturn of seeped fluid to c.v. system“Education” and produc

3、tion of immune system lymphocytesTransport of digested lipids from small intestinal lacteals 第3頁，共15頁，2022年，5月20日，12點49分，星期四Lymph CapillariesThin walled endothelium (no BM) with periodic one way valves. In general they parallel veins.Closed ends allow fluid flow inward only Pick up and recycle extra

4、 tissue fluid Lymph circulation due to ?Compare to Fig. 23.2第4頁，共15頁，2022年，5月20日，12點49分，星期四Location of Lymph CapillariesEverywhere, except for CNS and bone marrow, as well as cornea and cartilage.Special set of lymph capillaries in villi of small intestine = Lacteals第5頁，共15頁，2022年，5月20日，12點49分，星期四Da

5、maged valves or blockedlymph vessels ?Lymphatic vesselscomparable in structure to veins第6頁，共15頁，2022年，5月20日，12點49分，星期四Lymph capillaries converge to become collecting vessels and end up as eitherThoracic duct or right lymphatic ductThoracic (left lymphatic) ductLeft subclavian veinRight lymphatic duc

6、tRight subclavian veinCysterna ChyliFig 23.4第7頁，共15頁，2022年，5月20日，12點49分，星期四largest第8頁，共15頁，2022年，5月20日，12點49分，星期四LymphocytesAgranulocytes - large nuclei and small amount of cytoplasm Function in identification and inactivation/destruction of pathogensTypes of LymphocytesT Cells - cellular immunity -

7、 specific for previously identified pathogensT Helper, T Killer, T Suppressor, and memory cellsB Cells - humoral immunity - plasma cells produce antibodies specific to the antigen or pathogen; memory cellsNK cells - non-specific, provide immunological surveillance第9頁，共15頁，2022年，5月20日，12點49分，星期四Bone

8、Marrow: LymphopoiesisLymphocytes are later also produced in thymus, spleen and tonsilsFig 23.7第10頁，共15頁，2022年，5月20日，12點49分，星期四122C.t. loaded with LymphocytesLymphoid nodules are unencapsulated clusters of lymphocytes ( 1mm). Found beneath epithelial lining of respiratory, digestive & urinary tractsM

9、ucosa associated lymphatic tissue (MALT) in GI tract 5 tonsilsaggregate lymphoid nodules in small intestine (= Peyers patches)appendix - walls contain lymphoid tissueLymphoid Tissue = adenoids第11頁，共15頁，2022年，5月20日，12點49分，星期四Lymph Nodes 500 ( 1mm to 25 mm)Bean-shaped with hilusseveral afferent vessel

10、s, one efferent vessel Function?Popular term “lymph gland” is misnomer. Why?Contain lots of lymphocytes & MacrophagesClinical application: Swollen lymph nodesFig 23.9第12頁，共15頁，2022年，5月20日，12點49分，星期四Distribution of LNsCervical lymph nodes - drain head and neckAxillary lymph nodes - drain arms and bre

11、astsPopliteal lymph nodes - drain legs, drain into Inguinal lymph nodes - drain lower limbThoracic lymph nodes - drain thoracic visceraAbdominal lymph nodes - drain pelvic regionIntestinal and mesenteric lymph nodes - drain abdominal viscera第13頁，共15頁，2022年，5月20日，12點49分，星期四ThymusLocation above heart,

12、 posterior to sternumDivided into lobulesOnly lymphoid organ that does NOT fight antigens, it functions as “T-cell academy” Blood thymus barrier prevents premature stimulation of developing T-cellsInvolution after pubertyEpithelial cells produce thymic hormones第14頁，共15頁，2022年，5月20日，12點49分，星期四Largest lymphoid organSoft and very blood richRed pulp sinusoids containing RBCswhite pulp lymphoid tissueMajor Functions:Initiation of Immune response to antigens in bloodRemoval of aged