96. Subcutaneous pelvic region. Perineum. Ischioanal fossa.

Subcutaneus pelvic compartment.

• ↳ Includes the whole complex of soft tissues covering the pelvic outlet (Perineum).
• Rhombod in shape
• Boundaries:
• Ant: the inf. margin of the symphysis
• lat.: the inf. ramus of the pubic bone, the ramus of the ischeal bone. Sacrotubrecle lig.
• Post: the apex of the coccygeal bone.
• Divided into 2 triangle:

1. ① Urogenital triangle
2. ② Anal triangle

• The border btw. these triangles is the line btw. the ischeal tuberosities.

Surface Anatomy:

1. Skin - thin & haired
2. Superficial fascia: An extension of the sup. fascia of the antrolateral abdominal wall.
3. 2.1 Camper's fascia
4. 2.2 Colles fascia.
5. Superficial perineal muscles
6. Perineal body & membrane
7. Transverse ligament
8. Superficial perineal space.
9. Deep perineal space.

Transverse Ligament (Lig. Transversum Perinei):

• The anterior margin of the membrana perinei thickens to form the transverse ligament.
• This ligament spans the gap between the muscle and the pubic symphysis.
• It allows for the passage of vessels:
• In men: V. dorsalis profunda penis.
• In women: V. dorsalis profunda clitoridis.

Superficial Perineal Space (Spatium Superficiale Perinei):

• In men, this space contains:
• Corpora cavernosa and corpus spongiosum of the penis.
• Urethra.
• Ischiocavernosus, bulbospongiosus, and superficial transverse perineal muscles.
• Branches of the internal pudendal artery and vein.
• Pudendal nerve branches.
• In women, it accommodates the clitoris, urethra, and vagina.

Superficial Perineal Muscles:

• Ischiocavernosus Muscle: Present in both men and women, it surrounds the base of the penis in males and the clitoris in females.
• Bulbospongiosus Muscle: Also found in both genders, it envelops the bulb of the penis (in males) and the vestibular bulb (in females).
• Superficial Transverse Perineal Muscle: This muscle runs transversely across the superficial perineal space.

Perineal Body and Membrana Perinei:

• The perineal body serves as a central anchoring point composed of fibrous tissue and smooth muscle cells (SMCs).
• Deeper than the superficial muscles, the membrana perinei lines the outer aspect of the deep transverse perineal muscle.
• In women, the deep transverse perineal muscle is replaced by smooth muscle tissue.

Deep Perineal Space (Spatium Profundum Perinei):

• Bounded by the fascia pelvis parietalis and membrana perinei.
• In men, it houses:
• Bulbourethral glands.
• Deep transverse perineal muscle.
• External urethral sphincter muscle.
• Pudendal artery and vein.