From Vaginal Opening to Uterus Depth | Female Reproductive System ✨‍♀️😍 . The anatomy of the female pelvis is complex and includes several key structures and openings. Here’s an overview: Key Structures Pelvic Bones: Ilium: The largest part of the pelvis. Ischium: The lower, posterior part of the pelvis. Pubis: The anterior part of the pelvis. Sacrum: A triangular bone at the base of the spine, forming the back of the pelvis. Coccyx: The tailbone, located at the very base of the sacrum. Pelvic