Have you ever gotten in touch with your kidneys on a personal level? One result of my yoga practice is that I have a new connection with my internal organs, my bones, and my muscles, a lovely mix.
After five minutes in Dhanurasana (Bow pose), I have activated the abdominal and back muscles that by being engaged have opened the space for my internal organs to feel happy that I went to yoga class. From Iyengar's classic, The Light on Yoga, "Dhanu means a bow. The hands are used like a bow string to pull the head, trunk, and legs up and the posture resembles a bent bow."
Knowing myself, inside and out, right down to the kidneys, is the blessing that yoga gives me.