What prevents the backflow of urine from the urinary bladder to the kidneys?

peristaltic action of muscles of the ureters

peristaltic action of muscles of the kidneys

pulling action of the force of gravity

Question

What prevents the backflow of urine from the urinary bladder to the kidneys?

peristaltic action of muscles of the ureters

peristaltic action of muscles of the kidneys

pulling action of the force of gravity

dranz10 · Answer

I think it's the first one but check out the causes part of this website to be sure. https://www.nlm.nih.gov/medlineplus/ency/article/000459.htm Hope this helps!