What is the Difference Between Pelvic Diaphragm and Urogenital Diaphragm

The key difference between pelvic diaphragm and urogenital diaphragm is that pelvic diaphragm is a flat funnel-shaped membrane that extends from the walls of the pelvis and attaches to the hiatus analis while urogenital diaphragm is a triangle-shaped fibrous part that extends between the tubera ischiadica and the symphysis.

The pelvic floor muscles are located between the tailbone and the pubic bone within the pelvis. They support the bowel and bladder. The sphincters encircle the urethra, vagina, and anus as they pass through the pelvic floor. The pelvic floor is made up of fibrous muscular structures called the pelvic diaphragm and urogenital diaphragm. They attach to the bony base of the small pelvis, usually closing the pelvic outlet and thus providing the necessary support for the pelvic organs.

CONTENTS

1. Overview and Key Difference
2. What is Pelvic Diaphragm 
3. What is Urogenital Diaphragm
4. Similarities – Pelvic Diaphragm and Urogenital Diaphragm
5. Pelvic Diaphragm vs. Urogenital Diaphragm in Tabular Form
6. FAQ – Pelvic Diaphragm and Urogenital Diaphragm
7. Summary – Pelvic Diaphragm vs. Urogenital Diaphragm

What is Pelvic Diaphragm?

The pelvic diaphragm is a fibrous-muscular structure of the pelvic floor that extends from the walls of the pelvis and attaches to the hiatus analis, where the anus passes. It is a flat funnel-shaped membrane. Also, the pelvic diaphragm consists of the levator ani muscle and the coccygeus muscle.

Furthermore, the main function of the pelvic diaphragm is to support pelvic organs. In addition to that, all muscles of the pelvic diaphragm are innervated by direct branches from the sacral plexus (S3–S4).

What is Urogenital Diaphragm?

The urogenital diaphragm is a fibrous-muscular structure of the pelvic floor that extends between the tubera ischiadica and the symphysis. It is a fibrous triangle-shaped body part. The urogenital diaphragm closes the hiatus urogenitalis through which the urethra passes. In the area of ​​the center of the perineum, the urogenital diaphragm connects with the diaphragm pelvis. Moreover, axial bodies and glands are located on the lower side of the urogenital diaphragm.

In men, the urogenital diaphragm consists of the transversus perinei profundus muscle and the variable transversus perinei superficialis muscle, whereas in women, it consists of muscles of the sphincter urethrovaginalis and the compressor urethrae. Furthermore, the major function of the urogenital diaphragm is to support the urethra and maintain the urethrovesical junction. In addition to that, the urogenital diaphragm is innervated by
the pudendal nerve.

What are the Similarities Between Pelvic Diaphragm and Urogenital Diaphragm?

• The pelvic diaphragm and urogenital diaphragm are two fibrous muscular structures of the pelvic floor.
• Both diaphragms consist of specialized muscles.
• In the center of the perineum, the urogenital diaphragm connects with the diaphragm pelvis.
• Both play a very important supportive role.

What is the Difference Between Pelvic Diaphragm and Urogenital Diaphragm?

The pelvic diaphragm is a flat funnel-shaped membrane that extends from the walls of the pelvis and attaches to the hiatus analis, while the urogenital diaphragm is a triangle-shaped fibrous part that extends between the tubera ischiadica and the symphysis. Thus, this is the key difference between pelvic diaphragm and urogenital diaphragm. Furthermore, the pelvic diaphragm consists of the levator ani muscle and the coccygeus muscle. On the other hand, the urogenital diaphragm of men consists of the transversus perinei profundus muscle and the variable transversus perinei superficialis muscle, whereas the urogenital diaphragm of women consists of muscles of the sphincter urethrovaginalis and the compressor urethrae.

The infographic below presents the differences between pelvic diaphragm and urogenital diaphragm in tabular form for side-by-side comparison..

FAQ: Pelvic Diaphragm and Urogenital Diaphragm

What are the two parts of the pelvic diaphragm?

The levator ani muscle and coccygeus muscle are the two muscles of the pelvic diaphragm.

Why is the pelvic diaphragm weaker in females?

Pregnancy and childbirth are two reasons for having a weaker pelvic diaphragm in females.

What is the relationship between the diaphragm and the pelvic floor?

The diaphragm and the pelvic floor share a pressure relationship. When the diaphragm descends, the pelvic floor descends. When the diaphragm is elevated, the pelvic floor is elevated.

Summary – Pelvic Diaphragm vs. Urogenital Diaphragm

The pelvic diaphragm and urogenital diaphragm are two fibrous muscular structures of the pelvic floor that play a supportive function. Moreover, the pelvic diaphragm is a flat funnel-shaped membrane that extends from the walls of the pelvis and attaches to the hiatus analis, while the urogenital diaphragm is a triangle-shaped fibrous part that extends between the tubera ischiadica and the symphysis. The pelvic diaphragm supports pelvic organs, while the urogenital diaphragm supports the urethra and maintains the urethrovesical junction. So, this summarizes the difference between pelvic diaphragm and urogenital diaphragm.

Reference:

1. Knipe, Henry. “Urogenital Diaphragm: Radiology Reference Article.” Radiopaedia, Radiopaedia.org.
2. Raizada, Varuna, and Ravinder K Mittal. “Pelvic Floor Anatomy and Applied Physiology.” Gastroenterology Clinics of North America, U.S. National Library of Medicine.

Image Courtesy:

1. “1115 Muscles of the Pelvic Floor” By OpenStax – (CC BY 4.0) via Commons Wikimedia