figure 9. schematic representation of the interactions between the hypothalamic-pituitary-adrenal axis and the thyroid and immune function. crh: corticotropin-releasing hormone, sts: somatostatin, trh: thyrotropin releasing hormone, tsh: thyroid stimulating hormone, t4: thyroxine, t3: triiodothyronine, tnf- α : tumor necrosis factor- α , il-1: interleukin-1, il-6: interleukin-6. activation is represented by solid green lines and inhibition by dashed red lines.