Older texts have asserted the existence of a urogenital diaphragm, also called the triangular ligament, which was described as a layer of the

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

that separates the

deep perineal sac The deep perineal pouch (also deep perineal space) is the anatomic space enclosed in part by the perineum, and located superior to the perineal membrane. Structure The deep perineal pouch is bordered inferiorly by the perineal membrane, also know ...

from the upper pelvis, lying between the

inferior fascia of the urogenital diaphragm The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term "inferior fascia of urogenital diaphragm", used in older texts, is considered equivalent to the perineal membrane. It is the superior border of the su ...

(perineal membrane) and

superior fascia of the urogenital diaphragm Superior may refer to: *Superior (hierarchy), something which is higher in a hierarchical structure of any kind Places * Superior (proposed U.S. state), an unsuccessful proposal for the Upper Peninsula of Michigan to form a separate state *Lak ...

. While this term is used to refer to a layer of the pelvis that separates the

from the upper pelvis, such a discrete border of the sac probably does not exist. While it has no official entry in

Terminologia Anatomica ''Terminologia Anatomica'' is the international standard for human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology, a program of the International Federation of Associations of Anatomis ...

, the term is still used occasionally to describe the muscular components of the deep perineal pouch. The urethra and the vagina, though part of the pouch, are usually said to be passing through the urogenital diaphragm, rather than part of the diaphragm itself. Some researchers still assert that such a diaphragm exists, and the term is still used in the literature. The urethral diaphragm is an anatomic landmark used in

radiologic Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiatio ...

and

urologic Urology (from Ancient Greek, Greek wikt:οὖρον, οὖρον ''ouron'' "urine" and ''wiktionary:-logia, -logia'' "study of"), also known as genitourinary surgery, is the branch of medicine that focuses on surgical and medical diseases of t ...

classification of urethral injury. Specifically, when a retrograde

urethrogram A retrograde urethrography is a routine radiologic procedure (most typically in males) used to image the integrity of the urethra. Hence a retrograde urethrogram is essential for diagnosis of urethral injury, or urethral stricture. Uses Some indi ...

demonstrates extension of contrast from the proximal bulbous urethra into the

perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...

, there is an increase of grading of the injury from a Type 2 to a Type 3 classification. The term "urogenital diaphragm" is often confused with the pelvic diaphragm (

pelvic floor The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus muscle, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the lev ...

), which is a true diaphragm supporting many of the pelvic organs.

References

{{anatomy-stub Perineum