Lymph¶

Lymphatics at Region¶

Under Mucus glands = MALT
under GI = GALT
under Oral Epithelium = Tonsils
under REspiratory = BALT

Lymphatic System Schematic on Pathogen Elimination¶

graph TD
    X{Lympatic regions} ==> X1[Lymph node];
    X1 ==> X2[Lympatic Sysyem];
    X2 ==> X3[drains to Heart];
    X3 ==> X4[blood];
    X4 ==> X5[Spleen];

graph TD
    X{Local infection } ==> X1[immune cells at region];
    X1 ==>|fails to contain infection| X1a[Passage of Microbes and Immune cells to lymph node];
    X1a ==>|microbes passes | X1b[Sereis of Lymph node where they can be Phagocytosed and Presented];

Functions of Lymph node¶

Filter Lympatic fluid
Immune reaction to Antigen in Lymphatic Canal

Structure Of Lymph Node¶

graph TD
    X{Lymph Node } ==>|Outside TO inside | X1[Cortex];
    X1 ==> X2[Medulla];
    x1[COrtex] ==>|Outermost of Cortex| X1a[Superficial cortex- rich in B-cell<mark> forms Germinal Centres</mark>];
    X1a ==>|Be:octicons-arrow-down-24: Superficial cortex| X1b[Deep Cortex T-cell/Dendritic/MAcrophage rich region];
    y[Medulla] ==>|looks like Screens| y1[Medullary Cords = Lymphocytes/Macrophages/etc…];
    y1 ==>|be:octicons-arrow-down-24: Medullary COrds| y1a[Medullary Sinus];

graph TD
    X[Cortex] ==> X1a[Superficial Cortex];
    X1a ==> X1a1[Primary Nodule];
    X1a ==>|Nodule with White Centre| X1a2[Germinal Centre];
    Y[Follicular Dendritic Cells] ==>|forms Reticular mesh layer | X1a2

Lymph Drainage to Lymph node¶

graph TD
    X[Afferent Lymph vessels ] ==>|drains to Cortex | X1[Sub-capsular sinus];
    X1 ==>|f:octicons-arrow-down-24:s via a tube| X1a[Trabecular Sinus];
    X1a ==>|f:octicons-arrow-down-24:s via Medullary Cords | X1b[Medullary sinus];
    X1b ==>|drains to | X1c{One Efferent Lymph Vessels};

Blood Supply to Lymph node¶

graph TD 
    X[Artery via Medulla] ==>|to | X1[Superficial Cortex- Rich in Bcells];
    X1 ==>|from| X1a[Cuboidal/Columnar Endothelial= HEV for cell passage];
    X1a ==>|into Venules| X1b[drains back out via Medulla];

### Functions of HEVs - Absorption of water to Concentrate Lymph - Al B/T cell from blood to enter lymph node

Activation of Lymphocytes¶

graph TD
    X[Antigen] ==> X1[Gets Stuck on Follicular Dentrite cell ];
    X ==> X2[Phagocytosis by Macrophage];
    Y[B-cell Activation];
    X1 ==> Y;
    X2 ==> Y;
    Y ==> Yx[T-cell activation and B-cell class switching];
    Yx ==> Y1[Proliferate and Differentiate to Plasma and Memory Cell];
    Y1 ==>|Plasma Cells migrate to Medullary Cord | Y2[ Secrete Immunoglobulin into Efferent lymph vessel];
    Y1 ==>|Memory B-cells| Y3[Moves to other sites of Body for faster response on Secondary infection ];

Lymphadenitis

Swelling of lymph node by formation of Germinal Centres where a pathogen is identified (Example; Swelling on lymph nodes of neck during Oropharyngeal infection)

Activated Lymphocytes Travel to Site of Infection¶

graph TD
    X[Macrophage/Antigen activated Lymphocytes In Lymph-node] ==>|leaves via| X1[Lymphatic Drainage to Heart];
    X1 ==>|via Blood| X1a[To site of Infection];
    X1 ==>|via Blood| X1b[To Lymph-node via Highly Endothelial Capillaries in Lymph Node to recruit more Lymphocytes];