Regarding the fact that we are essentially tubes, there is a blessing that observant Jews say for 1800 years. when they leave the lavatory, Blessed are You, Lord our God, King of the universe, who has formed man in wisdom, and created within him numerous orifices and cavities. It is revealed and known before the Throne of Your Glory that if but one of them were to be blocked, or one of them were to be opened, it would be impossible to exist even for a short while. Blessed are You, Lord, who heals all flesh and performs wonders.