A doctor explains how through a video
It seems obvious to everyone to know when we’re about to fart or poop, but if you think about it, it’s not that intuitive to figure out how the butt distinguishes between the two, and if it wasn’t able to do that, it would be a big problem for everyday life. So basically, how does the butt discern when you’re about to poop and when to fart?
According to Matt Barton, Ph.D., a YouTuber and medical researcher at Australia’s Griffiths University, the difference comes down to the pectinate line, which separates the upper two-thirds and lower third of the anal canal that develops before we were born.
“In the embryo, there is a long tube known as the gut tube”, he explains in the video. “This will eventually become the digestive tract. This tube can be broken into the foregut, the midgut, and the hindgut”.
Around the seventh week, the hindgut and urinary system separate, leading to the formation of two separate exit points, one of which is the anal pit, or proctodeum. The proctodeum accounts for the lower third of the anal canal, ending at the pectinate line (aka dentate line).
“When wind or feces enters the anal canal, it will stretch the walls of the intestine, activating pressure receptors and taken back by visceral nerves, telling you that something is entering the canal”, says Barton. “But it’s not until it reaches the pectinate line that the stretch receptors become cutaneous receptors, like the skin, and from here onwards you can distinguish between wind and feces. Therefore, you can decide whether you’re safe or you need to use the bathroom”.
Source menshealth.com
