Pituitary Gland

• Aka
  Hypophysis

Embryology of Pituitary gland

1. During development the Neural tissue of Brain and epithelial tissue of mouth invaginate
2. Epithelial tissue invagination next to Neual tissue
3. Epithelial tissue invagination forms a pouch Rathky's Pouch
4. Rathky's Pouch then surrounds the Neural Invagination

Structures of Pituitary Glands

1. Neural tissue = Pars Nervosa 2. Epithelial tissue

1. The Tube surrounding the neural tissue = Pars Tuberalis

2. The remnant of Rathky's pouch = Pars Intermedia

3. The remaking part = Pars Distalis

graph TD
    subgraph Hypothalamus
    Q[Hypothalamus Regions} ==>|over Optic Chaism| Q1[Supra-optic nucleus ];
    Q ==>|Para = Next to Ventricles| Q2[Para-ventricular nucleus];
    Q ==> Q3[Hypothalamo-Hypophysiotropic Nucelus];
    end

    subgraph Pitutary
    X{Pituitary gland] ==> X1[Source of Origination];
    X1 ==> X11[Neural Tissue];
    X1 ==> X12[Epithelial tissue];
    X11 ==>|known as | X11a[Posterior Pituitary or Neuro Hypophysis];
    X12 ==> |known as| X112a[Anterior Pituitary];
    end

    Q1 -.->|axons| X11a;
    Q2 -.->|axons| X11a;
    Q3 -.->|axons to | Q311[Superior Hypophysial capillaries];

Blood Supply

graph TD
    X[Two arteries] ==> X1[Inferior Hypophysial artery];
    X ==> X2[Superior Hypophysial Artery];
    X1 ==>|supply| X1a[Neural Hypophysis/Posterior Pituitary];
    X2 ==>|supply the Stalk of Pituitary gland then 
    forms a vein| X2a[Supply the Anterior Pituitary];
    X1a  ==>|drains into | XX[Vein];
    X2a ==>|drains into | XX[Vein];

Hormones

graph TD
    subgraph Hypothalamus
    Q[Hypothalamus Regions] ==>|over Optic Chaism| Q1[Supra-optic nucleus ];
    Q ==>|Para = Next to Ventricles| Q2[Para-ventricular nucleus];
    Q ==> Q3[Hypothalamo-Hypophysiotropic Nucelus];
    end

    subgraph Pitutary
    X11a[Posterior Pituitary or Neuro Hypophysis];
    Q3 -.->|sends releasing hormones via blood| X1113[Anterior Pituitary Pars Distalis]
    X1113 ==>|has Hormones in cytoplasm =
    Attracts color| x31[Chromophilic];
    x31 ==> x31a[Acidiophilic cells ];
    x31a -.-> ac1[Somatotrophs];
    ac1 -.-> ac1a[GH];
    X31a -.-> ac2[Mammotrophs];
    ac2 -.-> ac2a[Prolactin];
    x31 ==> x31b[Basophilic];
    x31b -.-> bs1[Gonadotrophs] & bs2[Corticotrophs] & bs3[Thyrotrophs]
    bs1 -.-> bs1a[FSH] & bs1b[LH];
    bs2 -.-> bs2a[ACTH];
    bs3 -.-> bs3a[TSH]; 
    X1113 ==>| no hormones in cytoplasm =
    doest absorb color| x32[Chromophobic];
    end


    Q1 -.->|axon carries ADH to | X11a
    X11a ==>|releases ADH | X11ab[ADH into Blood vessel];
    Q2 -.->|axon carries Oxytocin to | X11a
    X11a ==>|releases| X11ac[Oxytocin into blood];