Exam 4: Perineum Flashcards
Perineum
A diamond-shaped space that is part of trunk below the pelvic diaphragm. Divided into 2 triangles by a line connecting 2 ischial tuberosities.
Triangles of perineum
Urogenital triangle
Anal triangle
Urogenital Triangle position
Lies in horizontal plane
Anal Triangle position
Tilted upward
Urogenital triangle boundaries
- Anterior: pubic symphysis
- Anterolateral: ischiopubic rami
- Posterior: Transverse line through ischial tuberosities
Layers of urogenital triangle
- Skin
- Superficial Perineal Pouch
- Perineal Membrane
- Deep Perineal Pouch
- Inferior Fascia of the Pelvic Diaphragm
Superficial Perineal Pouch made up of
- Superficial perineal fascia
2. Deep perineal Fascia
Superficial Perineal Fascia
Fatty Layer (superficial) Membranous layer (deep)
Colles’ Fascia
Membranous layer of superficial perineal pouch. Continuous with Dartos layer of the scrotum and Scarpa’s fascia
Superficial Perineal Pouch contents
- Perineal body
- Superficial transverse perineal muscle
- Ischiocavernosus muscle
- Crura of the Penis (Clitoris)
- Bulbospongiosus Muscle
- Bulb of the Penis (Vestible)
- Greater Vestibular Gland (females)
- Branches of the internal pudendal artery
- Branches of the Pudendal Nerve
Perineal body
Fibromuscular mass located between anal canal and bulb of penis
Muscle attachments on Perineal body
- Superficial transverse perineal
- Deep Transverse Perineal
- Bulbospongiosus
- Levator Ani
- External Anal sphincter
Episiotomy
Incision from posterior vaginal wall to perineal body. Prevents uncontrolled tearing of perineum
Muscle that does NOT attach to perineal body
Ischiocavernosus
Superficial Transverse Perineal Muscle Nerve
Perineal branch of pudendal nerve
Ischiocavernosus Nerve
Perineal branch of pudendal nerve
Bulbospongiosus muscle (Male)
Perineal branch of pudendal nerve
Impedes venous return by compressing the bulb of the penis, maintaining the erection. Constricts corpus spongiosum to empty the urethra at the end of micturition and during ejaculation
Bulbospingosus (Female)
Pudendal Nerve
Constricts vaginal orifice and maintains erection of clitoris
Greater Vestibular Gland
2 ovoid glands which are located in the superficial perineal pouch, posterior to the bulb of the vestibule
Greater Vestibular Gland homologous to:
Bulbourethral gland in the male.
Secretes mucus which lubricates the vagina during sexual intercourse