Yin-Yang: the Pituitary Gland
Created by an up-growth of the oral cavity he is composed of secretory epithelial cells.
He is the pars of masculinity (via ACTH), of fire/heat (via TSH) and of strength (via GH).
Created by a down-growth from the brain she is composed of unmyelinated axons of neurons. She is the pars of femininity, water (via ADH) and birth (via Oxytocin).
They are embryological opposites. As two halves, one operating without the other will cause the body to wither. Yet together, they make a whole bringing about balance - homeostasis - through the beautiful interplay of their signaling molecule secretions.
Indivisible we thrive.
The amazing Tao hypophysis.
Endless happiness and longevity.