Hypothalamic–pituitary–gonadal axis controls development, reproduction, and aging in animals. Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus by GnRH-expressing neurons. The anterior portion of the pituitary gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and the gonads produce estrogen and testosterone. In oviparous organisms (e.g. fish, reptiles, amphibians, birds), the HPG axis is commonly referred to as the hypothalamus-pituitary-gonadal-liver axis (HPGL-axis) in females. Many egg-yolk and chorionic proteins are synthesized heterologously in the liver, which are necessary for oocyte growth and development. Examples of such necessary liver proteins are vitellogenin and choriogenin. The HPA, HPG, and HPT axes are three pathways
Pituitary gland correlation between pituitary gland volume and Social Anxiety subscale scores was identified which provided a basis for exploring mediation. Again controlling for age, sex, and BMI, DHEA and DHEA-S have been found to be predictive of larger pituitary gland volume, which was also associated with increased ratings of social anxiety. This research provides evidence that pituitary gland volume mediates the link between higher DHEA(S) levels (associated with relatively early adrenarche) and traits associated with social anxiety. Children who experience early adrenarcheal development tend to have larger pituitary gland volume compared to children with later adrenarcheal development. The Greek physician Galen