All of the following are components of vaginal sphincter, EXCEPT:: (A) External urethral sphincter, (B) Internal urethral sphincter, (C) Bulbospongiosus, (D) Pubovaginalis
Answer is B. Four muscles compress the vagina and act as sphincters:PubovaginalisExternal urethral sphincterUrethrovaginal sphincterBulbospongiosusRef: Clinically Oriented Anatomy By Keith L. Moore, Ahur F. Dalley, II, Anne M. R. Agur, 2013, Page 389.