You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All of the following are components of sphincter of the lower genitourinary tract in females, EXCEPT: and explain in detail?
Muscles compress the vagina and act like sphincters: pubovaginalis, external urethral sphincter (especially its urethrovaginal sphincter pa), and bulbospongiosus. The internal urethral sphincter, which is formed from the detrusor muscle, is the upper and involuntary sphincter. Ref: Clinical and Surgical Anatomy, 2/e By Singh, 2006, Page 194; Clinically Oriented Anatomy by Keith L. Moore, Ahur F. Dalley, 1999, Page 372.