What is the pelvic floor?
The pelvic floor is the lower closure of the small pelvis. It consists of three layers of muscle with only narrow openings for the bowel, urinary and reproductive organs. From the inside out, these are: Diaphragma pelvis, Diaphragma urogenitale and the external sphincter layer.
The three muscle layers are arranged on top of each other like a fan and are connected to each other at several points by muscle fibers and fascia. In total, they are about four centimeters thick.
Diaphragm pelvis
The strongest and largest of these three layers is the diaphragma pelvis – the inner, funnel-shaped layer of the pelvic floor. It consists of two muscles (levator ani muscle and coccygeus muscle). The diaphragma pelvis has a longitudinal gap (levator slit) for the urinary and genital tracts. In women, this is the weakest part of the pelvic floor.
Diaphragma urogenitale
The urogenital diaphragm also has an opening for the urethra and (in women) vagina. The fibers around the opening for the urethra form the external urethral sphincter (bladder sphincter). In women, some muscle fibers radiate into the vaginal wall.
Outer sphincter layer
The external sphincter layer (external pelvic floor muscles) consists of several individual muscles. These mainly include the paired cavernous muscle (Musculus bulbocavernosus = M. bulbospongiosus) and the annular external anal sphincter (M. sphincter ani externus). In women, these two form an eight-shaped muscle loop around the vagina and anal canal.
What is the function of the pelvic floor?
The pelvic diaphragm, as the strongest layer, lifts and closes the anus, and is therefore important for fecal continence. The urogenital diaphragm, on the other hand, is important for urethral closure and thus urinary continence. The cavernous muscle, which is part of the external pelvic floor muscles, constricts the vaginal opening when it is tensed. It also contracts rhythmically and involuntarily during female orgasm, causing the clitoris to erect in a state of arousal. In men, this muscle supports urination and ejaculation.
Where is the pelvic floor located?
The pelvic floor is the muscular connective tissue lower closure of the small pelvis. It leaves only gaps for the intestines and the urinary and genital organs. It connects to the lumbar spine, pelvic bones and coccyx.