Perineum Flashcards
What is the perineum?
Region beneath pelvic diaphragm (levator ani and coccygeus)
How is the perineum divided?
Anal triangle and urogenital triangle
What are the layers of the anal triangle?
- Fatty superficial fascia
- Pudendal nerve and internal pudendal vessels
- Deep fascia
What is the fatty superfical fascia comprised of?
Thick subcutaneous fat
What does the fatty superficial fascia thicken to form?
Ischiorectal/Ischioanal fossae on either side of the anal opening
What is the ischiorectal fossa?
Deep fat filled indentation on either side of the anal opening.
What does the ischiorectal fossa contain?
Contains pudendal vessels and nerves which enter it through the lesser sciatic foramen and run in pudendal canal in lateral wall of the fossa. q
What level does the pudendal nerve arise?
(Ventral rami S2-4)
What does the pudendal nerve supply?
Supplies levator ani, lower anal canal and sphincter.
What does the pudendal nerves become?
Becomes dorsal nerve of penis/clitoris.
Where is the artery of the internal pudendal vessels?
Anterior trunk of internal line
What does the pudendal vein drain? Where does it drain into?
Drain prostatic venous plexus which drain penis and inferior rectal vessels.
Internal iliac vein.
Where do the branches of the pudendal nerve, artery and veins leave?
Medial wall of pedendal canal
What is the deep fascia shared with?
Shared with fascia of pelvic diaphragm
What does the anal traingle include?
External anal sphincter
How many fascia layers and spaces (poches) does the urogential triangle contain?
3 fascia layers and 2 spaces
What is the fascia shared between?
Pelvic diaphragm and urogential diaphragm
What does the deep perineal space or urogenital diaphragm contain?
Containing urethral sphincter and deep transverse perineal muscle
What does the superficial perineal space contain?
Contains bulbospongiosis, ischiocavernous and superficial transverse perineal muscles (partly overlie deep perineal space - muscles have to be reflected to see entire deep perineal space)
What are the layers from deep (superior) to superficial (inferior) of the urogential triangle?
- Fascia shared between pelvic diaphragm and urogenital diaphragm
- Deep perineal space or Urogential diaphragm
- Fascia (Inferior fascia of urogenital diaphragm or perineal membrane)
- Superficial perineal space
- Fascia (superficial fascia)
Where is the perineal body?
In the midline where fibres from transverse perineal muscles interlace - added support for pelvic viscera
