Urogenital triangle

2. Urogenital triangle It is bounded in front by the pubic arch & laterally by the ischial tuberosities .

3. Superficial fascia 1- The fatty layer is continuous with the fat of the ischiorectal fossa & the upper part of the thigh. It is replaced by the dartos muscle in the scrotum. 2- The membranous layer is attached posteriorly to the posterior border of the urogenital diaphragm & laterally to the margin of the pubic arch & anteriorly it is continuous with the membranous layer of the of the anterior abdominal wall . This fascia is continued over the penis or clitoris as a tubular sheath . In the scrotum or labia majora it forms a distinct layer . Superficial fascia of the thigh The fatty layer of the fascia extends into the thigh & continues down over the lower limb without iterruption. The membranous layer extends into the thigh & becomes attached to the deep fascia after about a fingerbreadth ( 8 cm ) below the inguinal ligament . Fatty layer

4. Superficial Perineal Pouch It is bounded below by the membranous layer of the superficial fascia & above by the urogenital diaphragm. It is closed behind by the fusion of its upper & lower walls. Laterally , it is closed by the attached membranous layer with the urogenital diaphragm to the margins of the pubic arch . Anteriorly, It communicates with the space lying between the superficial fascia & the muscles of the anterior abdominal wall .

5. Superficial Perineal Pouch In Male It contains structures forming the root of the penis,with the muscles that cover them. 1-The bulbospongiosus Ms.,are situated one on each side of the midline & cover the bulb of the penis & the posterior portion of the corpus spongiosum. 2- Ischiocavernosus Ms., they cover the crus penis on each side. Superficial Transverse Perineal Ms.,Each muscle arises from the ischial tuberosity & inserted into the perineal body. The function of them is to fix the perineal body in the center of the perineum. Nerve Supply : perineal branch of the pudendal N. Perineal body Small mass of fibrous tissue which is attached to the center of the posterior margin of the urogenital giaphragum. The external anal sphincter and 1 ( o ) & 3 ( In) are attached to it .

6. Penis It has a fixed root & a body . Its root is made up of 3 masses of erectile tissue called bulb of penis and R.& L. crura of penis. The bulb is attached to the undersurface of the urogenital diaphragm and is continued forward into the body to form Corpus Spogiosum ( spongy urethra is present within them ). Each crus is attached to side of pubic arch and lie side by side in the dorsal part of the body of penis, forming the corpora cavernosa.

7. Body Of Penis :It is made up of 2 dorsally placed corpora cavernosa, which communicate with each other . & a single corpus spongiosum applied to ventral surface. The 3 are erectile tissue. The corpus spongiosum expands to form the glans penis. On the tip of the glans penis is the external urethral meatus. Arteries from internal pudendal & veins into internal pudental. The corpora cavernosa by the deep arteries of the penis& the corpus spongiosum by the artery of the bulb & dorsal artery of the penis. Nerve supply: pudental N. & pelvic plexuses. Lymph Drainage: The skin into medial group of superficial inguinal nodes. The deep structures into internal iliac nodes .

8. Superficial Perineal Pouch In Female It contains the root of the clitoris & muscles that cover them. 1- Bulbospongiosus muscles : they surround the orifice of the vagina & cover the vestibular bulbs. Their fibers extend forward to gain attachment to the corpora cavernosa of the clitoris . 2- The ischiocavernosus muscles : They cover the crus of the clitoris Superficial T. perineal muscles : like male. Nerve supply : The perineal branch of the pudendal nerve. Perineal Body : Is larger than male . It is a wedge- shaped mass of fibrous tissue situated between the lower end of the vagina & anal canal . It supports the posterior wall of the vagina.

9. Female Urogenital Triangle It contains the external genitalia and orifice of the urethra & vagina Clitoris : It corresponds to penis. Is situated at the apex of the vestibule anteriorly. Root of clitoris is made of 3 erectile masses , the bulb of the vestibule & R. and L. crura . The bulb is divided into 2 halves The crura become the corpora cavernosa anteriorly. Body of clitoris :It consists of the 2 corpora cavernosa . Glans of the clitoris It is a small mass of erectile tissue that caps the body . The glans is partly hidden by prepuce. Blood supply, Lymph drainage , Nerve supply are similar to those of the male penis .

10. 1 Vulva ( Female external genitalia )3-Labia minora : their posterior ends are united to form the fourchette . Anteriorly, they enclose the clitoris , forming prepuse & posterior frenulum. 4-Vestibule : is a triangular area bounded laterally by the labia minora Anterior by the clitoris .Posterior by fourchette. 5- Vaginal Orifice : it is protected by hymen. 6Orifices of the ducts of the greater vestibular glands are found in the groove between the hymen & the posterior part of the labium minus. Blood supply : external & internal pudendal arteries . Nerve supply : Anterior parts are supplied by ilioinguinal & genital branch of genitofemoral . The posterior parts are supplied by branches of the perineal nerves & posterior cutaneous nerves of the thigh . Lymph drainage : into medial group of superficial inguinal nodes . 2

11. Urogenital Diaphragm It is a triangular musculofascial diaphragm. It fills the gap of the pubic arch .It is formed by the sphincter urethrae & the deep transverse perineal ms.These muscles are enclosed between a superior & inferior layers of fascia of this diaphragm. The inferior fascia is called perineal membrane. The closed space that is between the 2 layers of the fascia is known as the deepperineal pouch

12. Anteriorly , the 2 layers of fascia fuse , leaving a small gap beneath the symphysis pubis . They form the anterior transverse perineal ligament. Posteriorly , the 2 layers of fascia fuse with each other & with the membranous layer of the superficial fascia & the perineal body .

13. Deep perineal pouch in Male It contains the membranous part of the urethra; sphincter urethra; bulbourethral glands; the deep transverse perineal muscles; the internal pudendal vessels & their branches and the dorsal nerves of the penis. Membranous part of the urethra: It is about 1.3 cm long & lies within the urogenital diaphragm & is surrounded by the sphincter urethra muscle. It continuous above with the prostatic urethra & below with the penile urethra . It is the shortest & least dilatable part of the urethra. Bulbourethral Glands: they lie beneath the sphincter urethrae muscle. Their ducts pierce the perineal membrane & enter the penile portion of the urethra. Their secretion is as a result of erection. Deep transverse perineal muscles: They lie P. to sphincter urethrae. It arises from the ischial ramus & passes medially to be inserted into the perineal body. Internal Pudendal Artery : It enters the deep perineal pouch & gives rise to the As. Of bulb ; crura and dorsal a. of penis to skin& fascia. Sphincter Urethae Muscle : It surrounds the urethra in the deep perineal pouch. It arises from the pubic arch on the 2 sides & passes medially to encircle the urethra. Its nerve supply is the perineal branch of pudendal nerve. It is the means by which micturition can be voluntary stopped. Dorsal Nerve of Penis: It arises from pudendal N. It pass forward through deep perineal pouch to skin of penis.

14. Deep Perineal Pouch in Female It contains part of the urethra & part of vagina . The sphincter urethrae, which is pierced by the urethra & vagina. ( like male ). The deep transverse perineal muscles(like male ) . Internal pudendal vessesls & their branches and the dorsal nerves of theclitoris ( their arrangement similar to male) Urethra : it opens into the vestibule about 2.5 cm below the clitoris. It traverses the sphincter urethrae & lies immediately infront of the vagina. At the sides of the external urethral meatus are small openings of the ducts of the paraurethral glands .