Pelvic floor& Peritoneum Flashcards
Role of pelvic diaphragm
Continence and defaceation
Name the layers of the levator ani muscles from anterior to posterior
Levator prostate/sphincter vagina Puborectalis Pubococcygeus Iliococcygeus Ischiococcygeus
What forms a sling around the junction between rectum and anal canal?
Puborectalis
What forms a sling around prostate/vagina?
Levator prostate/sphincter vagina
What is closely related to the ischiococcygeus muscle?
Sacrospinous ligament
What is the ischiococcygeus also known as?
Coccygeus muscle
Tail wagging muscle (can flex coccyx)
What is found around the levator ani muscle?
Ligaments
Puboprostatic/pubovesical
Pubocervical& sacrocervical
What is the perineum?
Region inferior to the pelvic diaphragm
Overlies outlet of bony pelvis
Diamond shaped
Describe the perineum
Diamond shaped Anteriorly pubic symphysis Posteriorly coccyx Laterally ischial tuberosities Split into anal triangle and urogenital triangle
What is the perineal membrane?
Strong CT sheet which stretches across the urogenital triangle between ischiopubic rami
What is the external sphincter of the bladder also known as?
Sphincter urethrae
Found deep to perineal membrane
Maintains urinary continence
What is the perineum overlying the anal triangle called?
Ischioanal fossae (one on each side of anal canal)
What is found in the deep perineal pouch?
Vagina and urethra/ membranous urethra
Sphincter urethrae muscle and deep transverse perineal muscles
What passes through the small gap in perineal membrane just behind the pubic symphysis?
Veins from penis/clitoris
Join prostatic/vesical plexus
Where does the perineal body lie in females?
In the midline between lower end of vagina and anal canal
What is the perineal body?
Small wedge shaped mass of fibrous tissue
Attached to perineal membrane, levator ani and perineal muscles
What lies in the superficial perineal pouch in males?
2 corpora cavernosa diverge from each other as the 2 crura of the penis
Between 2 crura is enlarged proximal end of corpus spongiosum= bulb of penis
What forms the root of the penis?
The crura and the bulb of the penis
Attaches the penis firmly to the body via ischiopubic rami and perineal membrane
Where is the urethra found in the penis?
In the corpus spongiosum
What muscle covers each crus of the penis?
Ischiocavernosus muscle
What muscle is found on the under surface of the bulb of the penis? function?
Bulbospongiousus muscle
Helps maintain erection, functions in ejaculation with the ischiocavernosus muscles
Expels last drops of urine in micturition
What muscle helps maintain the position of the perineal body in males?
Superficial transverse perineal muscles
Where is the urethral orifice in a female?
Small opening just anterior to vagina
What is found on each side of the lower end of the vagina?
A mass of erectile tissue- the bulb of the vestibule
Join together anteriorly
What forms the body of the clitoris?
2 erectile corpora cavernosa- continuous with 2 crura attached to ischiopubic rami
Name the superficial perineal muscles in a female
Superficial transverse perineal muscles (separated by perineal body)
Ischiocavernosus muscle (around crus of clitoris)
Bulbospongiosum (encircles lower end of vagina superficial to bulb of vestibule)
What is the bulbospongiosus muscle also called?
Sphincter vaginae (part of levator ani)
What is found deep to the bulb of vestibule?
Greater vestibular gland- secretes mucus via a duct into vestibule
Describe the borders of the ischioanal fossae
Laterally- fascia covering Obturator internus
Medially- fascia in inferior surface of levator ani
posteriorly- sacrotuberous ligament
anteriorly- urogenital triangle
What is found within the ischioanal fossa?
Fat and CT fibres
Pudendal nerve passes along lateral wall in pudendal canal
Internal pudendal artery
What does the pudendal nerve divide Ito near the posterior border of the urogenital triangle?
Branch to penis/clitoris
Perineal nerve to muscles of deep and sup perineal spaces+ sensory to skin of perineum and posterior surface of scrotum/labia majors
What does the internal pudendal artery split up into at posterior border of urogenital triangle?
Deep and dorsal arteries of penis/clitoris
Describe venous drainage of penis
Deep dorsal vein-> prostatic venous plexus
Superficial vein-> superficial veins of upper thigh
How do you find the ischioanal fossa?
Reflect back the gluteus Maximus
Found on each side of the anal canal
What are the consequences of pudendal nerve damage?
Genital numbness
Fecal& urinary incontinence
In labour, what pain would still be felt after a pudendal nerve block and why?
Only anaesthetises post perineum
Pain in anterior perineum (ilioinguinal and genitofemoral nerves)
Pain of uterine contraction and cervical dilation (T10-L2 sympathetics)
