[The anatomy and function of the pelvic floor]

PELVIC FLOOR: Anatomy of the pelvic floor seemed to be clearly. In opposite the physiology of the Levator ani and the endopelvic fascia is not yet fully understood. Especially the anatomic form of the levator plate does not conform with physiologic concepts.

Pelvic structures can be divided in three groups: the hollow organs, the endopelvic fascia and the muscles. The M. levator ani is the muscle of the pelvic diaphragm. Its parts were given different names (Fig. 1, 4) depending on their function or localization. In anatomic studies the pelvic floor is described as basin-shaped. In contrast to the anatomic results based upon the evaluation of cadavers, dynamic MRI gave different concepts: at rest the levator ani probably has the shape of a dome and differ when contract. The urogenital diaphragm is mostly a fascia and contains only fair muscular components. Therefore, many authors do not accept the term "diaphragm" and the physiologic function is still a matter of discussion. The endopelvic fascia has to fix the organs in the pelvis and forms "streets" for vascular and nervous supply.

Describing anatomic structures in the common planes (transversal, sagittal, frontal) will help to understand CT- and MRI-imaging.