Lymphatic System and Thymus¶

graph TD
    X[Hydrostatic Pressure & Oncotic Pressure] ==> X1[fluid leaks from Capillaries];
    X1 ==>|drained back via| X1a[Lymphatic System];

Specialities of Lymphatic Vessels¶

Free ending tubes
Specialized squamous Epithelium
With flaps
anchoring filaments
valves inside
Zipper and button like attachment between cells

Functions¶

Passage of Fluids
Passage of Immune cells from Intersitium to blood
Microbes
Tumour cells

Thymus¶

Thymus Anatomy¶

Cells in thymus Cortex and Medulla¶

Epithelio-reticular cells = Teachers
Macrophage = killing Failed T-cells
Im-mature T cells = Students

graph TD
    X{Thymus} ==>|surrounded by| Xa[Dense Irregualr Connective Tissue];
    Xa ==>|separeates Paraenchyma into| Xa1[Lobules];
    Xa1 ==>xx1{2 regions}
    xx1 ==> Xa1a[Cortex];
    xx1 ==> Xa1b[Medulla];

Thymus Physiology¶

graph TD
    X[6 Types of Epithelio-reticular cells] ==>|functions as| X1[Teacher for T cells-2,3,5 ,Housing-1 ];
    Y[Immature T-clls] ==>|Passes| Y1[To medulla ten into Blood];
    Y ==>|failed| Y2[Eaten by Macrophages];

graph TD
    X{Immature T-cells from Morrow } ==>|via Segmented Capillaries| X1[into Thymus];
    X1 ==>|to cortex| X1a[<mark> Positive Selection by Erc -2];
    X1a ==>|fails to recognise CD4+ or CD8+| X1ax[Killed];
    X1a ==>|Recognises CD4+ or CD8+| X1a1[To Medulla];
    X1a1 ==>|Neagtive Selection| X1a2[Erc-5 checks Self Antigen on MHC-1 of CD4+ and CD8+];
    X1a2 ==>|fails| X1a2x[Killed];
    X1a2 ==>|Passes| X1a2a[Mature CD4+ or CD8+ cells into blood];

Di-George Syndrome

Failure of Thymus development from Pharyngeal Pouch ==> NO T-cell maturation ==> number of Cells in Lumph mode Deep Cortex