Lymphatic System
Lymphatic Circulation 淋巴循環
Lymphatic tissue
Lymphatic Organs
Lymph Trunks & Ducts
Lymphatic Capillaries 淋巴小管
introduction:
🚩The lymphatic vessels淋巴管collect lymph from most parts of the body and deliver it to the blood circulation primarily through the thoracic duct胸管
❗included:Diffuse lymphatic tissue→(Lymph nodule 淋巴小結)、Tonsils 扁桃腺、Lymph node 淋巴結、Thymus 胸腺、Spleen 脾臟
function:
(1)Draining excess interstitial fluid & plasma proteins from tissue spaces
由組織間引流回過多的組織間液跟血漿蛋白
(2)Transporting dietary lipids & vitaminsfrom GI tract to the blood
由消化管道(乳糜管)將飲食中的油脂與脂溶性vit運送至血液
(3)Facilitating immune responses 進行免疫反應
-recognize microbes or abnormal cells & responding
-cellular response(killing cells directly)
-humoral response(secreting antibodies)
statements:
(1)Found throughout the body except in Avascular tissue(cartilage, epidermis表皮 & cornea角膜
(2)Structure is designed to let tissue fluid in but not out
(a)anchoring filaments:keep tube from collapsing under outside pressure
(b)overlapping endothelial cells:open when tissue pressure is high (one-way valve)
(3)In GI tract腸胃道, known as lacteals乳麋 -contain chyle
statements:
(1)Vessels unite to form trunks & thoracic ducts
(2)Right side head, arm & chest empty into right lymphatic duct and rest of body empties into thoracic duct 胸管
(3)Lymph is dumped directly into left & right subclavian veins(左右鎖骨下靜脈)
Free cells:
c) Lymphocytes (plasma cells)
d) Macrophages
Diffuse散布型 lymphatic tissue
Reticular tissue:
a) Reticular cells
b) Reticular fibers(銀染→呈現黑色絲狀構造)
(collagen fiber 銀染→成土黃)
statements:
(1)Infiltration in the laminal propria of a mucous membrane常存在於固有層
(2)Lymphatic nodules 淋巴小結:Spherical aggregations of closely packed lymphocytes surrounded by diffuse lymphatic tissue 圓型的淋巴球聚集
in Small intestine 小腸→
同上，補充(1)→會擴展至黏膜下層submucosa
in Ileum 迴腸→
MALT is very prominent突出 in the ileum,These nodules are called Peyer patches
❤Lymphatic Nodules 淋巴小結
(1)Oval clusters of lymphatic cells with some extracellular matrix but NOT surrounded by a connective tissue capsule 淋巴球聚集但周邊沒有結締組織包圍
(2)The center of the nodule is called the germinal center增殖中心,It contains proliferating(增殖) B-lymphocytes and macrophages.
(3)T-lymphocytes are located outside the germinal center
(4)Lymphatic nodules filter and attack antigens 淋巴小結可過濾或
消除外來的抗原
Tonsils 扁桃腺
Palatine tonsils 腭扁桃腺
Pharyngeal tonsils 咽扁桃腺(adenoids)
statements:
(1)Located mainly in the pharynx 咽
(2)Large clusters of lymphatic cells and extracellular matrix that do not have a completed surrounding capsule
(3)Outer edges are invaginated(嵌入) to form crypts(隱窩) which allow for trapping of antigens to be presented to the lymphocytes
Lingual tonsils 舌扁桃腺
where:located in the posterosuperior wall of the nasopharynx 位於鼻咽上後壁
statements:
(1)Pseudostratified columnar epithelium 假多層柱狀上皮(又稱呼吸上皮)
(2)Lymph nodule 淋巴小球
(3)Germinal center 增殖中心
where:located in the posterolateral wall of the oral cavity口腔後側壁
statements:
(1)Tonsil crypts(扁桃腺隱窩)
(2)Stratified Squamous epithelium 多層扁平上皮
(3)Lymph nodule 淋巴小球
(4)Germinal center 增殖中心
where:located along the posterior one-third of the tongue沿後部三分之一的舌頭
statements:
(1)are covered by stratified squamous epithelium 多層扁平上皮
(2)has crypt 有隱窩
Lymph nodes 淋巴結
Thymus 胸腺
statements:
(1)Consists of lymphatic cells and extracellular matrix and is completely surrounded by a connective tissue capsule
具有淋巴細胞與細胞間質且外面包圍有完整的結締組織的被囊
Spleen 脾臟-Supporting tissue
introduction:
(1)located along the pathway of lymph vessels
(2)The primary function of a lymph node is to filter antigens from the lymph and initiate an immune response
可過濾淋巴液並引發初步之免疫反應
(3)Most apparent lymph node clusters occur as:
(a)Cervical lymph nodes 頸淋巴結
(b)Axillary lymph nodes 腋淋巴結
(c)Inguinal lymph nodes 鼠蹊淋巴結
Structure:
(1)Surrounded by a tough connective tissue capsule
包圍一層韌性的結締組織capsule 被囊
(2)Internal extensions of the capsule, trabeculae,project into the node
被囊會往內延伸出小樑
(3)Lymphatic cells surround the trabeculae and lymphatic sinuses provide a pathway for lymph flow
淋巴細胞會圍繞在小樑周圍 ,淋巴竇提供淋巴液流動的空間
(4)Lymph node is divided into outer cortex(皮質) and inner medulla(髓質)
(5)Cortex consists of nodules and sinuses called cortical sinuses
(6)The medulla contains medullary cords and medullary sinuses
(7)Afferent lymphtic vessels deliver lymph to the node
(8)Lymph exits nodes via efferent vessels at an indentation(節點) of the node called the hilum
In the medulla:
(1)Medullary cords contain macrophages, plasma cells, and small lymphocytes
(2)The dilated medullary sinuses (4)drain the lymph from the cortical region of the lymph node and course between the medullary cords toward the hilus of the organ.
hilus:
(1)Nerves, blood vessels, and veins that supply and drain the lymph node are located in the hilus
(2)Efferent lymphatic vessels
The cortex :
(1)has lymphatic nodules
(2)in lymphatic nodules,These lighter areas are the germinal centers
introduction:
(1)Large organ in infants (70 g)but atrophied as adult (3 g)
(2)2 lobed organ located in mediastinum 縱膈
(3)Supportive Capsule & trabeculae(is formed by Connective tissue) divide it into lobules(小葉)
(4)Each lobule has cortex & medulla 每一小葉均具有皮質與髓質
(5)Thymic–blood barrier prevents most circulating antigen from reaching the thymus cortex
避免正在發育的T cell 接觸到血液裏的抗原
(6)is the site of the terminal differentiation and selection of T cells
(7)Continues to grow until puberty(青春期)begins to regress in size and function
(8)In adults, it becomes replaced mostly by adipose connective tissue
Blood-ThymicBarrier
Components (From inside→outside)
(1)Capillary endothelium
(2)Endothelial basal lamna
(3)Epithelioreticular sheath
(4)Basal lamina of epithelioreticular cell
(5)Perivascular connective tissue sheath (and macrophages)
Supporting tissue
Parenchyma實質 (thymus tissue proper)
Capsule
Septa of connective tissue between lobules
Medulla(palely)
Cortex(dark)
-contains mature T lymphocytes, reticular epithelial cells
-Hassall’s corpuscles哈氏小體
-tightly packed T cell precursors(thymocytes), reticular epithelial cells and macrophages
-T lymphocytes undergoing differentiation
Parenchyma
Vascular
structure:
(1)Capsule→
-dense fibro-elastic tissue with smooth muscle
-covered by mesothelium
-part of visceral peritoneum內臟腹膜 (serous membrane漿膜)
(2)Trabeculae
(3)Reticulum: reticular tissue
White pulp
Red pulp
(1)lymphatic tissue and lymphatic nodules(splenic corpuscles脾小體) may have germinal centers
(2)central artery
(3)free cells: lymphocytes、plasma cells、macrohages
(1)Pulp(or splenic ) cords
-reticular tissue, macrophages
-all circulating blood elements
(2)Venous sinuses(靜脈竇)
Artery
Vein
(1)Splenic artery enters spleen at hilum
(2)Trabecular artery(in trabeculae)
(3)Central artery(in white pulp)
-periarterial sheath (lymphatic tissue)
-eccentric in splenic corpuscles在脾小體中心
(4)penicillus artery筆毛為動脈(in pulp cords)
-branches of central artery are straight, lie close together, like bristles of a brush
(a) pulp artery
(b)sheathed artery
(c)terminal arteriole or arterial capillary
(1)Venous sinuses
-littoral cells, elongated lining cells(not usual endothelim, non phagocytic)
-basement membrane incomplete
-outer layer of reticular fibers
(2)Pulp Veins(red pulp)
-wide lumen(腔)
-endothelial lining
(3)Trabecular Veins
-lack muscular media
(4)Splenic Vein(hilum)
延伸第1點:Closed circulation of blood>>>
terminal arteriole →Venous sinuses
延伸第1點:Open circulation>>>>
terminal arteriole →pulp cords→Venous sinuses