The urogenital triangle is made up of a superficial and deep layer of fascia, with a middle layer of skeletal muscle called the urogenital diaphragm. The superficial perineal space or pouch is a small compartment of the perineum. The superficial perineal space is inferior to the urogenital diaphragm and its inferior fascia, which is enveloped by Colles fascia.
The superficial perineal space is an open compartment that is open anteriorly. Here it communicates freely with the potential space lying between the anterior abdominal muscles and the superficial fascia of the anterior abdominal wall. This space contains erectile tissue, muscles, and neurovascular structures associated with the external genitalia.
Anterior: by communicating freely with the potential space lying between the superficial fascia of the anterior abdominal wall and anterior abdominal muscles
Superior: by the perineal membrane which is the inferior fascia of the urogenital diaphragm
Inferior: by Colles fascia, which is the deep membranous layer of the superficial perineal space. This fascia covers the muscles located in the superficial perineal pouch
Contents of the superficial perineal space in both sexes:
Although they have different functions in males and females, the ischiocavernosus, bulbospongiosus, and the transverse perineal muscle are present in the superficial perineal space in both sexes as well as the urethral artery.
Contents of the superficial perineal space in males:
Contents of the superficial perineal space in females:
All component of the urogenital system derives from the intermediate mesoderm.
The superficial perineal space receives vascular supply from the internal pudendal artery, which branches off the internal iliac artery. The perineal artery supplies the transverse perineal muscle in both males and females. In males, the posterior scrotal artery supplies the posterior portion of the scrotal sac, the artery to the bulb of the penis supplies the urethra, the dorsal artery of the penis supplies the glans penis and prepuce of the penis, and the deep artery of the penis supplies the corpus cavernosum of the penis. In females, the posterior labial artery supplies the posterior portion of both the labia majora and minora, the artery to the bulb of the vestibule supplies the vestibular bulbs, the dorsal artery of the clitoris supplies the clitoral crura, and the deep artery of the clitoris also supplies the clitoral crura.
Lymphatics from the superficial perineal space accompanies the internal pudendal artery and its branches, which then drain into the internal iliac lymph nodes.
Pudendal nerve branches are present in the superficial perineal space: In females, the posterior labial nerve has a medial and lateral branch and runs along the lateral part of the urethral triangle to supply the skin of the labia majora. In males, the posterior scrotal nerve also has a medial and lateral branch and also runs along the lateral part of the urethral triangle to innervate the skin of the scrotum.
Ischiocavernosus muscle: is a muscle that is just below the surface of the perineum and is present in both men and woman. It is innervated by the perineal nerve which is a branch of the pudendal nerve. In males, it aids in stabilizing an erect penis, and it tenses the vagina during orgasm in females.
Bulbospongiosus muscle: is a superficial muscle in the perineum. In males, it covers the penile bulb, and in woman, it covers the vestibular bulb. In both men and woman, receives its nerve supply from the deep branch of the perineal nerve. In males, it contributes to erection and the contraction of orgasm and ejaculation. In females, it also contributes to clitoral erection and the contraction of orgasm and ejaculation.
Transverse perineal muscle: is part of the pelvic floor. Its innervated by the pudendal nerve and functions to support the pelvic floor fixates the perineal body and aids in the expulsion of semen in males and the expulsion of the last drops of urine in both males and females.
In cases of traumatic rupture of the bulbous urethra, there is extravasation of urine within the superficial perineal space. However, urine can pass into the penile region (outside of Buck fascia) as well as scrotal and lower abdominal wall (outside of the Colles and Scarpa fascia). Historically, the prevention of the uremia and the sepsis that can eventually follow was by the application of the 'perineal section.'
Same anatomic pathways account for the progression of necrotizing fascitis - Fournier gangrene within the perineal region. The Buck fascia and the Colles fascia account for limiting the further progression of the fascitis beyond and beneath their attachments, which is secondary to obliterative endarteritis of the arteries supplying the region due to endotoxemia.
The Bartholin glands are within the superficial perineal space. These glands secrete a fluid that lubricates the vagina. In normal circumstances, the Bartholin glands are not visible, but if the glands are blocked, they can swell and present as a fluid-filled cyst. If the fluid gets infected, a condition known as bartholinitis occurs. The most common organisms associated with bartholinitis is Staphylococcus spp. and Escherichia coli. The diagnosis requires a pelvic exam, and the treatment is incision and drainage with marsupialization. Unfortunately, a simple incision and drainage are associated with recurrences.
|||Communication between spaces formed by fasciae of male external genitalia and perineum: computed tomographic cadaveric study and clinical significance., Park BJ,Sung DJ,Yeom SK,Sohn YM,Kim YH,Cho SB,Kim JJ,Park SH,, Journal of computer assisted tomography, 2010 Mar-Apr [PubMed PMID: 20351502]|
|||Bolla SR,Varacallo M, Anatomy, Abdomen and Pelvis, Deep Perineal Space 2019 Jan; [PubMed PMID: 30855860]|
|||The secondary external inguinal ring and associated fascial planes: surgical anatomy, embryology, applications., Mirilas P,Mentessidou A,, Hernia : the journal of hernias and abdominal wall surgery, 2013 Jun [PubMed PMID: 23404213]|
|||Alves-Lopes R,Neves KB,Montezano AC,Harvey A,Carneiro FS,Touyz RM,Tostes RC, Internal Pudental Artery Dysfunction in Diabetes Mellitus Is Mediated by NOX1-Derived ROS-, Nrf2-, and Rho Kinase-Dependent Mechanisms. Hypertension (Dallas, Tex. : 1979). 2016 Oct; [PubMed PMID: 27528061]|
|||Eovaldi BJ,Sharma S, Anatomy, Bony Pelvis and Lower Limb, Peroneal Artery 2019 Jan; [PubMed PMID: 30855864]|
|||Pereira A,Pérez-Medina T,Rodríguez-Tapia A,Chiverto Y,Lizarraga S, Correlation between Anatomical Segments of the Pudendal Nerve and Clinical Findings of the Patient with Pudendal Neuralgia. Gynecologic and obstetric investigation. 2018; [PubMed PMID: 30007962]|
|||Wan EL,Dellon AL, Injury to the perineal branch of the pudendal nerve in men: Outcomes from surgical resection of the perineal branches. Microsurgery. 2018 Feb; [PubMed PMID: 29457288]|
|||Bordoni B,Leslie SW, Anatomy, Abdomen and Pelvis, Pelvic Floor 2019 Jan; [PubMed PMID: 29489277]|
|||Zifan A,Reisert M,Sinha S,Ledgerwood-Lee M,Cory E,Sah R,Mittal RK, Connectivity of the Superficial Muscles of the Human Perineum: A Diffusion Tensor Imaging-Based Global Tractography Study. Scientific reports. 2018 Dec 14; [PubMed PMID: 30552351]|
|||Mistry V,Halder A,Saad N, Primary posterior perineal hernia: Incidental CT diagnosis of a rare pelvic floor hernia. Journal of medical imaging and radiation oncology. 2019 Apr; [PubMed PMID: 30431708]|
|||Mundy AR,Andrich DE, Urethral trauma. Part I: introduction, history, anatomy, pathology, assessment and emergency management. BJU international. 2011 Aug [PubMed PMID: 21771241]|
|||Chennamsetty A,Khourdaji I,Burks F,Killinger KA, Contemporary diagnosis and management of Fournier's gangrene. Therapeutic advances in urology. 2015 Aug [PubMed PMID: 26445600]|
|||Mallikarjuna MN,Vijayakumar A,Patil VS,Shivswamy BS, Fournier's Gangrene: Current Practices. ISRN surgery. 2012 [PubMed PMID: 23251819]|
|||Cobo F,Rodríguez-Granger J,Sampedro A,Navarro-Marí JM, Bartholin's abscess due to Dialister micraerophilus in a woman presenting with repetitive bartholinitis episodes. Medecine et maladies infectieuses. 2018 May; [PubMed PMID: 29397243]|
|||Reis HL,Pinho CR,Ferreira Dde C, Diagnosis and management of acute puerperal bartholinitis caused by Escherichia coli. Revista da Sociedade Brasileira de Medicina Tropical. 2014 Nov-Dec; [PubMed PMID: 25626668]|