How many holes does the human body have?

Photo looking at the back of a woman sitting alone in the opening of a concrete pipe on a sunny day. .

The human body is extraordinarily complex, with several openings and a few exits. But exactly how many holes does each person have?

It sounds like a simple enough question to answer — list the openings and add them up. But it's not quite that easy once you start considering questions like: "What exactly is a hole?" "Does any opening count?" And "why don't mathematicians know the difference between a straw and a doughnut?"