“Blessed are You, Lord our God, King of the Universe, who formed man in wisdom and created in him many orifices and cavities. It is revealed and known before the throne of Your glory that were one of them to be ruptured or blocked, it would be impossible to survive and stand before You, even for a moment. Blessed are You, Lord, Healer of all flesh who does wondrous deeds.”
“A blessing of thanks for the intricate wonders of the human body.
Even the smallest variation in the human genome can cause potentially fatal illness. The more we understand of the complexity of life, the more we appreciate ‘How numerous are Your works, O Lord. You have made them all in wisdom. The earth is full of Your creations’ (Psalm 104:24).
This blessing is a rejection of the idea that the spirit alone is holy, and physical life bereft of God.”
(Commentary from the Koren Siddur)