And eventually, this entire umbilical vein, this entire blood vessel, along with a ductus venosis, eventually diminishes in size, and the flow of blood decreases. Eventually, it completely stops functioning. It closes. And this usually takes place within days of the clamping process. So following birth, the duct that's venosis also constricts and eventually diminishes in size to a non functional structure. Now, what about the doctor's arteriosis?