Perineum Flashcards
What are the boundaries of the perineum?
- Anterior: Pubic symphysis
- Lateral: Ischial tuberosities
- Posterior: Coccyx
What are the components of levator ani?
- Puborectalis
- Pubococcygeus (poboanalis, puboprostaticus/vaginalis)
- Iliococcygeus
What are the origins and insertions of puborectalis?
Origins: Posterior surface of pubis
Insertions: Posterior surface of pubis (forms sling around anal canal)
What are the origins and insertions of pubococcygeus?
Origins: Posterior surface of pubis
Insertions: Anococcygeal raphé
What are the origins and insertions of iliococcygeus?
- Origins: Whitle line on obturator internus
- Insertions: Anococcygeal raphé
What is the innervation and function of the levator ani?
Innervation:
- Anterior rami of S4
- Pudendal nerve
Function:
- Forms pelvic floor
- Supports pelvic viscera
- Reinforces external anal sphincter
What are the structures associated with the perineum?
- Perineal membrane
- Perineal body
- Perineal pouches (superficial/deep)
What is the transverse perineal line?
Imaginary line between ischial tuberosites dividing perineum into urogenital and anal triangles.
What are the attachments of the perineal membrane?
- Anterior: Missing
- Lateral: Ischiopubic rami
- Posterior: Perineal body and Colles’ fascia
What are the structures piercing the perineal membrane?
- Urethra
- Vagina (females)
- Nerves and vessels
What attaches to the perineal body?
- Superficial/deep transverse perineal muscles
- External anal sphincter
- Bulbospongiosus
What are the contents of the deep perineal pouch?
- Membranous urethra
- External urethral sphincter
- Bulbourethral glands
- Deep transverse perineal muscles
- Anterior aspects of ischioanal fossa
- Nerves and vessels of the penis/cloitoris
What are the contents of the superficial perineal pouch?
- Male external genitalia (testes, spermatic cord, penis)
- Clitoris
- Ischiocavernosus
- Bulbospongiosus
- Superficial transverse perineal muscle
- Greater vestibular (Bartholin’s) glands (females)
What are the boundaries of the anal triangle?
- Base: Transverse perineal line
- Lateral: Sacrotuberous ligaments
- Apex: Coccyx
What are the contents of the anal triangle?
- Anal canal
- Ischio-anal fossa