This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Gynaecology & Obstetrics
Episotomy extended posteriorly beyond perineal body injuring structure posterior to it, which structure is injured? 
Select and explain. 
A. External anal sphincter, B. Ishiocavernous, C. Bulbospongiosus, D. Urethral sphincter
A: External anal sphincter
Answer: A: External anal sphincter 
Explanation: Episotomy extended posteriorly beyond perineal body will injure External anal sphincter. Extension of the incision in median episiotomy involve the rectal mucosa. structures attaching on perineal body Bulbospongiosus: anteriorly, surrounding urethra and vaginal opening Transverse perinei: laterally External anal spincter: posteriorly, surrounding anal opening.