The narrowest pa of the ureter is at the
Ureterovesical junction is the anatomical position where the ureters join the urinary bladder. This is the narrowest of the ureter. Ureters are surrounded by the valves called as ureterovesical valve which will prevent the vesicoureteral reflux. Ref - urologyhealth.org
Uretero - pelvic junction
Illiac vessel crossing
Pelvic uterer
Uretero - vesical junction
Abdomen and pelvis