Pelvic Floor

Pelvic Diaphragm

  • covered superior and inferior by superior and inferior fascia of the pelvic diaphragm

levator ani and coccygeus

  • tendinous arch = white line of levator ani (ischial spine > fascia covering obturator internus, inferior pubic ramus)
  • anterior fibres = levator prostatae/sphincter vaginae (around prostate/vagina>perineal body)
  • intermediate fibres = puborectalis (around rectum/anal canal > external anal sphincter)
  • posterior fibres = pubococcygeus and iliococcygeus (>median raphe and coccyx)
    • pubococcygeus (<tendinous arch and inferior pubic ramus)
    • iliococcygeus (<tendinous arch)
  • median raphe = levator plate of levator ani (coccyx > rectum)
  • (ischio-)coccygeus (ischial spine, sacrotuberous lig > coccyx)


  • between pubis, ischial tuberosities and coccyx
  • divided by ischail tuberosities, transverse perineal mm

anterior urogenital triangle

  • superior layer of urogenital diaphragm (cont with inferior fascia of the pelvic diaphragm)
  • deep perineal pouch/space
    • deep transverse perineal mm (ischial tuberosity > perineal body)
    • sphincter urethrae and sphincter urethraevaginalis (voluntrary)
    • bulbourethral/Cowper’s glands (M; ducts > bulbous urethra)
    • internal pudendal artery (M; >bulb, crura, dorsal a&n of the penis)
  • perineal membrane = inferior layer of urogenital diaphragm
  • superficial perineal pouch/space
    • bulbospongiosus (perineal body > pubis; F=cover bulb of vestibule, separated by vagina/urethra; M= cover bulb penis)
    • greater vestibular/Bartholin’s glands (F; duct>post vestibule)
    • bulb of penis (M; bulbospongiosus, corpus spongiosum, urethra)
    • ischiocavernosus mm (ischial tuberosity > pubis; M = cover corpus cavernosa)
    • superficial transverse perineal mm (ischial tuberosity > perineal body)
  • perineal body (betw vagina/bulb penis and anus)
  • membranous/Colles’/superficial perineal facia

anal triangle (post to ischial tuberosity)

  • inferior fascia of pelvic diaphragm = anal fascia
  • external anal sphincter (anococcygeal lig > perineal body)
  • anococcygeal body/ligament (anal sphincter > coccyx)
  • ishorectal fossae (betw inferior facia of pelvic diaphragm, sacrotuberous ligament, gluteus maximus, obturator internus fasia, urogenital perineum)


  • apex (<urachus, ant), body, fundus (post), neck (inferior angle)
  • trigone (betw ureteric [post-lat angles] and urethral [inf] orifices)
  • posterior (base), superior and inferolateral (2) surfaces
  • median umbilical ligament = urachal remnant
  • ureteric and prostatic impressions
  • Bladder wall <4-5mm with outer adventitial, middle smooth muscle (inner and outer longitudinal, middle circular fibres), lamina propira and transitional epithelium. It is trabeculated apart from smooth trigone. Mucosa loosley attached to muscle, so when contracted becomes wrinkled.
  • internal urethral sphincter (involuntary around neck)
  • surrounded by perivesical fat
  • vesical plexus > internal iliac vv
  • lymph > internal iliac > para-aortic nodes


  • A = retropubic/prevesical space (of Retzius; fat pad and venous plexus)
  • A/lat = obturator internus
  • P = cervix, vagina, seminal vesicles, rectovesical fascia, rectum
  • S = peritoneum, uterus
  • I = prostate, pelvic fascia
  • I/lat = levator ani


  • patent urachus, urachal cyst, sinus or diverticulum
  • bladder diverticulum (usually boys from muscular abnormality
  • Hutch/periureteric diverticulum
  • agenesis or duplication (rare)

Male Urethra ~20cm

Posterior urethra (5cm)

  • Prostatic urethra (3cm, widest part) – urethral/prostatic crest (post wall), verumontanum = seminal colliculus (enlargement on crest), prostatic utricle (on verumontanum), ejaculatory ducts (2, inferior to prostatic utricle), prostatic sinus (lat to prostatic crest), prostatic ducts (15-20, in prostatic sinus)
  • Membranous urethra (2cm) – within the external urethral sphincter = sphinter urethrae m (in urogenital diaphragm).

Anterior/spongy urethra (15cm). Penoscrotal junction between bulbous and penile amrked by supensory ligament of penis creating a bend. Lined by glands of Littre

  • Bulbous urethra – contained within corpus spongiosum penis except for proximal 2cm (pars nuda). Bulbourethral/Cowper’s duct openings in intrabulbar fossa
  • Penile/pendulous urethra – navicular fossa (in glans), lacuna magna (in navicular fossa), external urethral orifice/meatus


  • posterior urethral valves (1/6000, membrane equivalent to hymen, verumontanum>dist prostatic urethra)
  • anterior urethral valve
  • anterior urethral diverticulum
  • urethral duplication (rare, usually coronal plane)

Female Urethra 4cm

  • paraurethral/Skene’s ducts (> vestibule)
  • external urethral sphincter at urogenital diaphragm

Male Reproductive System

Prostate Gland 3.5cm

  • base (superior) and apex
  • anterior, posterior and inferolateral (2) walls
  • cave of Retzius = retropubic space
  • puboprostatic ligament (<ant-inf prostate)
  • levator prostatae
  • true/prostatic capsule (may be deficient post)
  • periprostatic venous plexus
  • fibrous sheath = false capsule (pelvic fascia, cont with puboprostatic ligaments))
  • periprostatic fat
  • rectoprostatic/Denonvillier’s fascia (lower part of rectovesical pouch separating seminal vesicles/prostate and rectum)
  • Lowsley’s anatomical lobes (5):
  • anterior lobe = isthmus (part of TZ)
  • posterior lobe (post to urethra, inferior to ejaculatory ducts; ~PZ)
  • lateral lobes (2, spans all zones forming bulk of gland)
  • median/middle lobe (betw urethra and ducts;~CZ)

zone classification:

  • peripheral zone (PZ, 70%, posterior to urethra and CZ)
  • central zone (CZ, 25%, around ducts)
  • transition zone (TZ, 5%, inside CZ around urethra proximal to duct-urethra junction)
  • anterior fibromuscular zone/stroma (ant to urethra, non-glandular)
  • central gland (CZ and TZ, lower T2 signal)
  • inner (TZ) and outer (PZ and CZ) gland

Neurovascular supply

  • < inferior vesical and middle rectal aa
  • periprostatic plexus >internal iliac vv and vertebral venous plexus
  • lymph > internal iliac and obturator nodes
  • parasympathetics < pelvic splanchnic nn

age > larger TZ (BPH), smaller CZ

surgical pseudocapsule (betw ↑TZ and ↓PZ)

Seminal Vesicles (5cm)

  • P = Denonvillier’s facia, rectum
  • ampulla of vas deferens (sup to vesicles)
  • ejaculatory ducts (2cm, fusion of ampulla and vesicle)

Scrotum and Contents

testis (4 x 2.5 x 3cm; upper and lower poles)

  • tunica albuginea = fibrous capsule
  • mediastinum of the testis (post)
  • fibrous septa
  • seminiferous lobules (200-300)
  • seminiferous tubules (1-3 per lobule)
  • rete testis (~20, in mediastinum)
  • efferent ducts (10-15)

epididymis (6-7cm; posterolateral; head = globus major 7-8mm di, body/corpus and tail/caudo = globus minor 1-2mm di)

  • epididymal duct (convoluted, in epididymis)

vas deferens (P/med to testis, loops lateral to inferior epigastric anterior to ureter; 45cm)

  • ampulla of the vas deferens

tunica vaginalis (obliterated processus vaginalis; ant, lateral and med)

sinus epididymis (betw epididymis and testis)

appendix of testis (remnant paramesonephric/Müllerian duct)

appendix of epididymis (remnant mesonephric duct)

spermatic cord (testis to deep inguinal ring; vas deferens, testicular a&v, cremasteric a, a to vas, genital br of genitofemoral n, lymph)

  • fibrous sheath of external spermatic, cremasteric and internal spermatic fascia


  • superficial/Dartos fascia (>Camper’s fascia)
  • external spermatic fascia (>external oblique aponeurosis)
  • cremaster muscle and fascia (>internal oblique)
  • internal spermatic fascia (>transversalis fascia)
  • fibrous median raphe = scrotal septum (Dartos fascia)
  • gubernaculum testis = scrotal ligament (>inf scrotum; upper gubernaculum degenerates)


  • testicular a < aorta
  • deferential a (<inferior vesical) and cremasteric a (<inf epigastric) > spermatic cord and epididymis
  • posterior scrotal a (<internal pudendal), external pudendal (<femoral a) and cremasteric a (<inf epigastric) > scrotum
  • pampiniform plexus of veins (sup scrotum)> testicular/internal spermatic v > IVC and L renal v
  • cremasteric venous plexus (<epididymis; posterior to testis) > pampiniform plexus
  • lymph from testis > paraaortic LN at L1-2
  • lymph from scrotum > superficial inguinal LNs


  • undescended testes (33% preterm, 3-4% term, 0.7% 1y; 80-90% lie in inguinal canal proximal to internal inguinal ring, 10-20% in abdomen)
  • absent appendix testis
  • congenital hydrocoele (patent processus vaginalis)
  • cysts in spermatic cord (from isolated areas of patent processus vaginalis)


  • root, body
  • Buck’s fascia = deep fascia of the penis (<external spermatic fascia/external oblique aponeurosis, >suspensory ligament of penis to symphysis pubis)
  • copora cavernosa (dorsal, form crura > ishiopubic ramus)
  • tunica albuginea (covering corpus cavernosa)
  • incomplete fibrous septum = intercavernous septum of Buck’s fascia
  • corpus spongiosum (ventral, form bulb and glans)
  • glans penis (distal spongiosum, covers cavernosa)
  • dorsal aa of the penis (paired, dorsal to cavernosum, in Buck’s fascia; > glans; < internal pudendal a)
  • cavernous/deep aa > bulb and crura (<internal pudendal a)
  • cavernous veins > emissary vv > deep dorsal vein (betw tunica albuginia and Buck’s) > internal pudendal vv
  • superficial dorsal v (betw skin and Buck’s fascia) > periprostatic venous plexus
  • lymph > superficial and deep inguinal nodes

Female Reproductive System

Vulva and Vagina

  • labia majora
  • vestibular bulbs covered by bulbospongiosus
  • labia minora
  • vestibule (betw labia minora)
  • vagina (8cm)
  • anterior and posterior walls
  • anterior and deep posterior and lateral fornices
  • vaginal artery < internal iliac a
  • vaginal branch of uterine a
  • vaginal venous plexus > internal iliac v
  • lymph upper 1/3 > internal and external iliac nodes; middle 1/3 > internal iliac nodes; lower 1/3 > superficial inguinal nodes


  • P = rectouterine pouch of Douglas, perineal body
  • lat = levator ani, ureters, vestibular bulb,urogenital diaphragm

Uterus (8 x 5x 3cm; prepubertal ~4cm)

  • fundus, cornua (superolateral angles), body, isthmus
  • cervix (supravaginal and vaginal parts; inner stroma and outer zone)
    • supravaginal (endocervix) and vaginal portio (ectocervix) parts.
    • nonkeratinizing squamous epithelium covers the portio, mucus secreting columnar epihtlelium covers the endocervix, with squamocolumnar junction (variable position) at the proximal end of the transformation zone (where squamous and columnar epithelia coexist)
  • internal os
  • cervical canal
  • longitudinal ridges on anterior and posterior walls of cervical canal
  • plicae palmatae (branches of ridges running laterally in nulliparae)
  • cervical glands
  • Nabothian cysts (dilations of cervical glands in endocervical canal)
  • external os (ant wall vagina; anterior and posterior lips postparity)
  • anteverted and anteflexed
  • outer myometrium (midsecretory phase 25mm)
  • inner myometrium (5mm, hypoechoic band = subendometrial halo on USS; junctional zone on MRI)
  • endometrium
  • central echogenic stripe (menstrual and early proliferative phase 2-4mm, secretoryphase 8mm, postmenopausal <3mm, HRT 10mm)
  • uterine artery < internal iliac a (broad lig > internal os > anast with ovarian a)
  • venous plexus in lower broad ligament > ovarian v > internal iliac v
  • lymph fundus > paraaortic nodes; body and cervix > internal and external iliac nodes, superficial inguinal nodes


  • A = uterovesical pouch, bladder
  • P = pouch of Douglas, ileum, colon
  • lat = broad lig, uterine vessels, ureters


  • levator ani (> cervix via pelvic fascia)
  • parametrial ligaments (cervix > pelvic walls)
    • transverse cervical/cardinal lig (pelvic sidewalls > cervix and upper vagina)
    • pubocervical lig/fascia (pubis either side of pubovesical lig >cervix)
    • uterosacral lig (cervix and upper vag > lower sacrum)
  • rectouterine folds (lat marins of pouch of Douglas)
  • broad lig (parametrial connective tissue; round lig, uterine vessels, lymph, ovarian ligs)
    • mesosalpinx
    • round lig (upper lateral uterus > ingunal canal > labia majora; remnant lower gubernaculum)
  • epoöphoron (remnant mesonephric duct in mesosalpinx and mesoovarium) > paroöphoron > Gartner’s duct (in broad lig and wall of vagina)
  • vesicular appendages of epoöphoron = hydatids of Morgagni (adjacent to fimbriae)


  • retroverted and/or retroflexed
  • Mullerian agenesis (uterine agenesis, vagina rudementiray or absent; associated with renal or skeletal abnormalities)
  • uterus didelphys (double uterus with double cervix and vaginal partition or lower uterus fused)
  • bicornuate uterus (> 40mm separation between horns with >75°; >10mm depth of myometrium)
    • uterus bicornis bicollis (double horned partially fused uterus, double cervix)
    • uterus bicornis unicollis (double horned partially fused uterus, single cervix)
  • uterus unicornis unicollis (single horn on one side; associated with abnormal ipsilateral kidney)
  • septate uterus (septa in uterus ± cervix ± vagina)
  • arcuate uterus (uterus indented in fundus)

Uterine/Fallopian Tubes (~10cm)

  • interstitial/uterine part (piecing uterus)
  • isthmus
  • ampulla (dilated and tortuous; fertilisation usually occurs)
  • infundibulum
  • fimbriae and fimbria ovarica = ovarian fimbria

Ovaries 3 x 2 x 2 cm

  • ovarian fossae (post surface broad lig, close to infundibulum)
  • medial and lateral surfaces
  • anterior and posterior borders
  • superior and inferior poles
  • childhood microcystic ovary follicles <2mm
  • >8y multicystic/multifollicular ovary >/= 6 of >4mm
  • adult 3 x 1.5 x 2cm, 2-8g, postmenopausal <2cm, 1-2g
  • mesovarium (ovaries > posterior surface broad ligament)
  • suspensory lig of ovary = infundibulopelvic lig (sup-lat extension of broad lig; ovary > pelvic side wall; ovarian vessels, lymph, n plexus)
  • (proper) ovarian lig (continuation of round lig; lower pole ovary >uterus; remnant upper gubernaculum)
  • ovarian artery (aorta at L1/2 > mesovarium > ovarian hilum)
  • pampiniform plexus > ovarian v > IVC and L renal v
  • lymph > preaortic nodes at L1/2


  • A = obliterated umbilical a
  • P = internal iliac a, ureter
  • I = levator ani
  • S/lat = fimbriae
  • lat = obturator vessels and n, floor of ovarian fossa


  • medulla (vascular) and cortex (cellular)
  • germinal epithelium (cont with peritoneum at hilum)
  • tunica albuginea = fibrous capsule
  • primary ovarian follicles (up to 750,000 each)
  • immature follicles (~70,000)
  • mature follicle = Graafian follicle
  • corpus luteum (postovulatory, of pregnancy or menstruation)
  • corpora albicantia (scarred, previously ruptured follicles)

Pelvic Vasculature

  • common iliac artery bifurcation @pelvic brim

External Iliac Artery (med border psoas)

  • inferior epigastric artery (>ant abdo wall > rectus sheath; round lig and vas deferens cross sup-lat; >cremasteric a)
  • deep circumflex iliac a (>ASIS >anterior abdo wall mm)
  • common femoral artery (CFA) under inguinal lig


  • A = peritoneum, vas deferens, testicular vessels, round lig, ureter
  • P/M = external iliac v

Internal Iliac Artery

anterior trunk/division (> ischial spine)

  • umbilical/superior vesical arteries (> upper bladder, obliterated umbilical artery = medial umbilical ligaments)
  • obturator artery (>obturator canal; also <inf epigastric a [V25%] or <obturator and inferior epigastric [V5%])
  • inferior vesical artery (M;> lower bladder, ureter, prostate, seminal vesicles)
  • uterine artery (F; in broad lig > uterus, upper vagina, fallopian tubes, ovary)
  • vaginal artery (F; > lower vagina)
  • middle rectal artery (usually with inferior vesical a; >prostate, seminal vesicles, rectum)
  • internal pudendal artery (>lesser sciatic foramen> ischioanal fossae >perineum; > genitalia, inferior rectal a)
  • inferior gluteal artery (>greater sciatic foramen; >sciatic nerve)
    • persistent sciatic artery (V1%, enlarged inferior gluteal associated with replaced SFA/profunda)

posterior division (>gr sciatic foramen)

  • iliolumbar artery (ascends, >iliac and lumbar branches, > psoas and iliacus, cauda equina)
  • lateral sacral arteries (superior and inferior pairs, > anterior sacral foramina > sacral canal, mm and skin over back, anast median sacral a)
  • superior gluteal artery (> greater sciatic foramen, > mm of pelvic wall and gluteal region)


  • A = ureters, ovary, fallopian tube, gonadal vessels
  • P = internal iliac v
  • lat = external iliac a&v, psoas
  • med = peritoneum, bowel

Iliac Veins

  • follow arteries
  • left common iliac vein crosses behind R CIA


  • internal iliac nodes > common iliac nodes > para-aortic nodes

Pelvic and Lower Limb Nerves

Lumbar Plexus

  • ant rami L1-4; within psoas major
  • iliohypogastric and ilioinguinal (>inguinal canal) nn (L1; > skin inguinal and scrotum, motor internal oblique and transversus)
  • genitofemoral n (L1-2; >spermatic cord, skin inf-med to inguinal lig)
  • lateral femoral cutaneous n (post division L2-3; >skin lateral iliac to knee)
  • femoral n (post division L2-4; between psoas and iliacus > under inguinal lig > ilipsoas, anterior mm of thigh, pectineus, anterior/medial cutaneous branch)
    • saphenous n (>medial crural cutaneous nn)
  • obturator n (ant division L2-4; lateral pelvic wall > upper obturator canal; A/lat = CIV; > adductor mm)

Sacral Plexus

  • ant rami L4-S4, anterior to piriformis > greater sciatic foramen
  • superior gluteal (L4-S1) and inferior gluteal (L5-S2) nn (>glutei, tensor fascia latae)
  • sciatic nerve (L4-S3; anterior sacrum/piriformis >greater sciatic foramen; >post mm of thigh, leg mm)
    • tibial nerve (>popliteal fossa > underflexor retinaculum)
    • common fibular/peroneal nerve (med knee)
      • superficial peroneal n (>peroneal mm, superficial to extensor retinaculum)
      • deep peroneal n (>ant comp mm, deep to retinaculum)
  • posterior femoral cutaneous n (S1-3; >post thigh to knee)
  • pelvic splanchnic nn (S2-4 and inferior hypogastric plexus; > bladder, descending colon, erection penis/clitoris)
  • pudendal nerve (S2-4; >pelvic floor and perineum; >inferior rectal, perineal nn, dorsal n of penis)
  • perineal n (S4; >levator ani, skin)
  • nerves to piriformis, quadrates femoris, obturator internus