Final answer:
Once entering the pelvis, the ureters run along the lateral pelvic wall before they enter the bladder wall obliquely, forming a physiological sphincter that prevents reflux of urine back into the ureter.
Step-by-step explanation:
Once the ureters enter the pelvis, they initially run laterally, hugging the pelvic walls, as part of their course towards the bladder. As the ureters near the bladder, they turn medially and enter the bladder wall obliquely. Hence, the correct answer to the question of which wall they course along once entering the pelvis, would be the C) Lateral pelvic wall.
This medial turn towards the bladder and the oblique entry are significant because they create a physiological sphincter that allows urine into the bladder while preventing its reflux back into the ureter. This anatomical arrangement protects against vesicoureteral reflux, which could lead to serious urinary tract infections (UTI) if this one-way valve mechanism were absent.