Exam V: Perineum Flashcards
Pelvic Diaphragm Borders
Diamond shaped region with same boundaries as pelvic outlet
Floor is skin & fascia
Roof is pelvic diaphragm and fascia
Region between legs externally and shallow compartment internally
Divided into anterior urogenital triangle and posterior anal triangle
The pelvic diaphragm and urogenital hiatus are superior boundaries to the perineum
Deep Perineal Pouch
Deep perineal pouch: perineal membrane + urogenital diaphragm: reinforces pelvic diaphragm and supports pelvic viscera
Perineal membrane is the superior boundary for deep perineal pouch which is analogous with the pelvic diaphragm
Contents of the Perineal Pouches
Superficial Pouch:
2 Erectile Bodies
corpus cavernosum/crus
corpus spongiosum/bulb
3 Muscles:
bulbospongiosus
ischiocavernosus
superficial transverse perineal m.
Deep Pouch Muscles: deep transverse perineal external urethral sphincter (M/F) urethrovaginal sphincter (F) compressor urethrae (F/M?)
Perineal Body/Central Tendon
Small mass of fibromuscular tissue, larger in females
Fascia attaching to perineal body: Colle’s fascia (superficial perineal fascia) Perineal membrane Superior fascia of the UGD Deep perineal fascia
Muscles attaching to perineal body: Superf/Deep trans. perineals Bulbospongiosus External anal sphincter Portion of Levator ani
Episiotomy
Mediolateral: permits wide expansion but may involve the ischo-anal fossa
Median: damages the perineal body
Muscles attached to perineal body are cut
If levator ani is damaged: prolapse of uterus
Innervation damaged: incontinence
Even if you sew it too tight the muscle won’t be able to relax enough
Ischoanal Fossa
Lies between skin and pelvic diaphragm
Allows expansion during child birth and defecation
Divided into posterior and anterior recesses
Superficial Perineal Fascia
2 Layers of Superficial Perineal Fascia
subcutaneous, fatty superficial layer
membranous, deep layer = Colle’s fascia
Colle’s Fascia: continuous with Scarpa’s fascia
Attaches to:
–fascia lata in thigh
–pubic arch
–posterior border of perineal membrane
Extends over penis/scrotum as dartos fascia (tunic- contains smooth muscle)
Deep Layer of Perineal Fascia
Continuous with fascia of external oblique and external spermatic fascia
Forms tubular investment for shaft of penis as far as glans and proximally surrounds crura and bulb (Buck’s fascia)
Surrounds crura and bulb, covers superficial perineal muscles; in perineum, termed external perineal fascia or Gallaudet’s fascia. Attaches to inferior fascia of UGD
Forms suspensory ligament of penis/clitoris
Rupture of Male Urethra
- Lacerations of spongy urethra + Buck’s fascia intact = urine spreads along the shaft of the penis
- Lacerations of spongy urethra + Buck’s fascia torn = urine leaks into the superficial pouch/scrotum, along the shaft of the penis, superficial to Buck’s fascia, and along the anterior abdominal wall deep to Scarpa’s fascia in abdomen
- Above UGD: urine leaks into pelvic cavity below peritoneum
- Ruptured Membranous Urethra: deep perineal space
- Ruptured spongy urethra, Buck’s fascia, and Colle’s fascia = urine leaks to same areas as #2 + pelvic cavity
Male External Genitalia
Corpus spongiosum: contains urethra
Bulb – enlarged region at base of corpora spongiosum, penetrated by urethra
Glans – expanded, cap-like portion, has external urethral orifice
Corona – edge of glans, extends backwards over corpora cavernosa
Crura- legs of corpus cavernosa, attached to the ischiopubic ramus
Male Perineal Muscles
Bulbospongious: Functions to empty urethra, compress deep dorsal vein and erectile tissue, contracts during ejaculation
Ischiocavernosus: Moves blood from caudal to rostral, compresses deep dorsal vein
Superficial transverse perineal: stabilizes perineal body
Male Perineal Ligaments
Suspensory ligament – deep fascia, arises from pubic symphysis, forms sling attached to deep fascia of penis (Buck’s fascia)
Fundiform ligament – subcutaneous tissue that arises from linea alba, SUPERIOR to pubic symphysis, also forms sling (Scarpa’s fascia derived)
Peyronie’s Disease
fibromatosis of TUNICA ALBUGINEA and Buck’s fascia
Connective tissue overgrowth in hands causing excessive contraction – cut out extra tissue
This happens in penis, fibrous plaques in penis causing painful bend during erection ONLY
Varicocele
Look like bag of worms that feel heavy/sand like
Blood from the paminiform plexus isn’t being drained
Left side more often because it drains into the left renal vein sometimes impinged by the superior mesenteric artery and not so much on the right side because just has to drain into the IVC
Female Perineum
Vulva – includes:
- Mons pubis- collection of subcutaneous fat in front of pubic symphysis
- Labia majora-fat filled prominence, contain termination of round ligament of uterus
- Labia minora- folds of skin devoid of fat and hair
- Clitoris- prepuce, frenulum
- Vestibule- space between the labia minora; bulb of the vestibule deep to labium minora
- Greater vestibular glands
Functions:
sensory & erectile tissue of arousal and intercourse
direct flow of urine
prevent entry of foreign material into urogenital tract