If we base ourselves on the definition in topology, the male human body has 7 orifices and the female has 8. Can you guess which ones they are?
At first glance, the question of how many holes the human body has seems simple: just list the holes and count them. But, according to mathematicians and topologists, the answer depends less on anatomy and more on How to define an “orifice”.
In everyday language, a hole can mean almost any opening or depression. In mathematics, specifically in topology, the definition is much more rigorous. A true orifice is one that completely passes through an objectsuch as the hole in a donut. “In topology, a hole is something you can stick your finger through,” explains mathematician and science popularizer James Arthur to . A dead-end depression, on the other hand, is not a hole in the topological sense.
This distinction helps explain why even familiar objects cause confusion. Consider a straw: some people say it has two holes, others say it has one, and some even say it has none. To a topologist, a straw has a single hole that runs through it from end to end, just like a donut. The two visible openings are simply the two ends of the same hole.
Applying this logic to the human body, many candidates are quickly eliminated. Pores, breast ducts, and sweat glands may be openings, but do not pass through the body. The ear canals also do not qualify as they end at the eardrum. Even the urethra is excluded, because it does not connect two external openings.
What remains are the openings that connect internally to allow complete passage. According to this definition, the mouth, the anus and the two nostrils they form a linked system that counts as multiple openings but fewer holes. Furthermore, humans have four tear pointsthe small openings in the eyelids that drain tears into the nasal cavity. These also connect to the same internal system.
This is where topology becomes crucial: when multiple openings are internally connected, they often count as fewer holes than openings. A useful analogy is a piece of underwear, which has three openings but only two topological holes. Using similar reasoning, mathematicians conclude that the human body has seven holesdespite having eight interconnected openings.
There may be an exception. In female anatomy, the vagina attaches to the uterus and the fallopian tubes, which open into the abdominal cavity. Since it is possible, at least theoretically, to pass through this system and exit, some mathematicians consider it as an additional hole.
The final count? From a topological perspective, humans have seven or eight holes. As experts note, the enigma is not limited to anatomy, but rather to the way in which the connections define the structure.
