The anal fascia is the inferior layer of the diaphragmatic part of the

pelvic fascia The pelvic fasciae are the fascia of the pelvis and can be divided into: * (a) the fascial sheaths of ** the obturator internus muscles ( fascia of the obturator internus) ** the piriformis muscles ( fascia of the piriformis) ** the pelvic floor ...

, which covers both surfaces of the levatores ani. It is attached above to the

obturator fascia The obturator fascia, or fascia of the internal obturator muscle, covers the pelvic surface of that muscle and is attached around the margin of its origin. Above, it is loosely connected to the back part of the arcuate line, and here it is conti ...

along the line of origin of the

levator ani The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis. It is attached to the inner surface of each side of the ...

, while below it is continuous with the superior fascia of the

urogenital diaphragm Older texts have asserted the existence of a urogenital diaphragm, also called the triangular ligament, which was described as a layer of the pelvis that separates the deep perineal sac from the upper pelvis, lying between the inferior fascia of ...

, and with the fascia on the sphincter ani internus. The layer covering the upper surface of the pelvic diaphragm follows, above, the line of origin of the levator ani and is therefore somewhat variable. In front it is attached to the back of the

pubic symphysis The pubic symphysis (: symphyses) is a secondary cartilaginous joint between the left and right superior rami of the pubis of the hip bones. It is in front of and below the urinary bladder. In males, the suspensory ligament of the penis attache ...

about 2 cm. above its lower border. It can then be traced laterally across the back of the superior ramus of the

pubic bone In vertebrates, the pubis or pubic bone () forms the lower and anterior part of each side of the hip bone. The pubis is the most forward-facing (ventral and anterior) of the three bones that make up the hip bone. The left and right pubic bones ar ...

for a distance of about 1.25 cm, when it reaches the obturator fascia. It is attached to this fascia along a line which pursues a somewhat irregular course to the spine of the

ischium The ischium (; : is ...

. The irregularity of this line is because the origin of the levator ani, which in lower forms is from the pelvic brim, is in man lower down, on the obturator fascia. Tendinous fibers of origin of the muscle are therefore often found extending up toward, and in some cases reaching, the pelvic brim, and on these the fascia is carried.

References

Pelvis Fascia {{Portal bar, Anatomy

See also

References