What are the structures of the male perineum?
External genitalia
- Scrotum
- Urethra
- Testis
- Penis
Perineal muscles
Anal canal
What are the structures of the female perineum?
External genitalia
- Labia
- Urethra
Perineal muscles
Anal canal
What are the two triangles of the perineum?
Urogenital
Anal
What is the name of the thin sheet of deep fascia that stretches between the right and left of the pubic arch below the pubic symphysis?
Perineal membrane
What is fixed to the perineal membrane?
External genitalia
Identify
Deep transverse perineal muscle
Identify
Bulbospongiosus
Identify
Ischiocavernosus
Identify
Superficial transverse perineal muscle
Identify
Bulbospongiosus
What is the nerve supply of this?
External anal sphincter
- Pudendal nerve (inferior anal nerve)
What is the main action of the external anal sphincter?
Relaxes from a tonic contraction
What is the nerve supply of this?
Pudendal nerve (brnch. perineal nerve)
What is the action of the bulbospongiosus in women?
Compresses vestibular bulb
Constricts vaginal orifice
What is the action of the bulbospongiosus in men?
Compresses penis bulb
Contributes to erection, orgasm contractions and ejaculation
What is the nerve supply of this?
Ischiocavernosus
Pudendal nerve (brnch. perineal nerve)
What is the function of the ischiocavernosus in females?
Tense vagina during orgasm
What is the function of the ischiocavernosus in males?
Stabilise erection by compressing corpus cavernosum
What is the nerve supply of this?
Superficial transverse perineal muscle
Pudendal nerve (brnch. perineal nerve)
What is the function of the superficial transverse perineal muscle?
Fixation and stabilisation of perineal body
What is the nerve supply of this?
Deep transverse perineal muscle
Pudendal nerve
What is the function of the deep transverse perineal muscle?
Fixation and stabilisation of perineal body
Expulsion of semen and urine
What is the nerve supply of the external urethral sphincter?
Pudendal nerve
What 4 muscles converge towards the perineal body?
Levator ani
Bulbospongiosus
Superficial transverse perineal
External anal sphincter
What are the boundaries of the superficial perineal pouch and what is it?
A potential space between the deep and superficial perineal fascia
What are the boundaries of the deep perineal space and what important structure is found here?
Deep perineal fascia (below)
Superficial urogenital diaphragm (above)
Contains the external urethral sphincter
What muscle is surrounded by the deep perineal space?
Deep transverse perineal muscle
summary of pelvic spaces
What are the 4 parts of the male urethra?
Pre prostatic
Prostatic
Membranous
Spongy
What is the widest part of the male urethra and why?
Prostatic
- opening for ejaculatory duct
- can be compressed
What is the narrowest part of the male urethra?
Membranous
- Contains external urethral sphincter
What is alcock’s canal?
Canal in the pelvis where the internal pudendal vein and artery pass as well as the pudendal nerve
What is the major content of the ischioanal fossa?
Adipose lobules
Why is the ischioanal fossa a common site of abscess formation?
E.coli from anal tears
What can happen when ischioanal abscesses become large and burst?
They can form fistulae
