Pelvis Flashcards
Pelvic Joints + Ligs
- Secondary Cartilaginous
- lumbosacral lig
- IV disc
- Iliolumbar lig
- pubic symphysis
- ZP (facet) plane synovial
- sacroiliac
- sacrococcygeal
pelvic diameters
- Conj line = ant/post, sup PS -> mid sacral prom
- true conj = back of PS -> prom, shorter than conj, narrowest btwn PS + prom, unaffected by pelvic lig relaxation
- diagonal = bottom PS -> sacral prom, measured per vaginum, used to estimate true conj and to tell if wide enough for baby
- oblique = sacroiliac joint -> iliopubic eminence
- cant take conj/true conj w/o imaging
Pelvic Muscles
- Floor = pelvic diaphragm = hammock - suspends viscera
- walls = obturator internus (lat ant wall) + piriformis (G. sciatic foramen -> femur)
Diaphragm + Innervation
- diaphragm = levator ani + coccygeus
- levator ani = levator ani n (S4), inf recta n. (from pudendal nerve, S3-S4), coccygeal plexus
- Coccygeus = S3-S4
Levator Ani
- puborectalis = from pubic bone, forms sling around GI tract
- most medial, immediately lat to rectum -> maintains perineal flexure
- relaxation = defecation
- pubococcygeus = pubic bones -> coccyx at anococcygeal raphe (mid muscle)
- iliococcygeus - ileum -> anococcygeal raphe (on outside)
Pelvic Borders
- anterior wall = pubic bones, pubococcygeus, puborectalis
- lat wall = obturator internus, piriformis
- post wall = coccygeus
- floor = pubococcygeus, puborectalis
Male Pelvic Cavity Spaces
- Retropubic space = PS-bladder
- rectovesical space = rectum-bladder
Female Pelvic Cavity Spaces
• Rectopubic space (btwn pubis + rectum)
• Rectouterine pouch (of Douglas) = btwn uterus + rectum
• Vesicouterine pouch = btwn uterus + bladder
○ Paravesical space
○ Pararectal space
○ Retrorectal space
Thickened Pelvic Fascia
- support viscera (in females)
- pubovesical lig - from bone to bladder (thickened endopelvic lig)
- transverse cervical lig (from uterus to wall)
- uterosacral lig - from uterus back to sacrum
- broad lig - peritoneal sheet, top of pelvic organs, from peritoneal cavity
Sacroiliac Lig
- plane synovial + syndesmosis = compound joint
- ant + post parts
- blends w/2 other sacro-ligs
- ossifies w/age
Pubic Symphysis
- supported by sup/inf pubic arcuate ligs
- fibrocartilage + hyalin cartilage
Sacrotuberous + sacrospinous ligs
- sacrotuberous lig (vertical) = sacrum -> ischial tuberosity
- sacrospinous lig (horizontal) = sacrum -> ischial spine
- prevent tilt up of sacrum
- form G/L sciatic foramen
L5-S1
- common disc herniation = spondylolisthesis, fracture of pars interarticularis)
- forward sliding prevented by articular processes (ZP joints) + iliolumbar ligs
Transverse + Ant/Post (AP) diameter
- transverse (inlet + outlet) - btwn ischial tuberosities = max diameter of inlet
- AP diameter - lower border of PS + coccyx tip = max diameter of outlet
- PS has inc mobility at end of pregnancy -> relaxing hormones to diameter + sacroiliac
urogenital diaphragm (UGD)
= deep perineal (DP) pouch
- inf boundary = perineal mem (spans ischiopubic rami)
- inferior to pelvic diaphragm
- perineal body = central tendon
Pelvic Viscera
- pelvic diaphragm + below peritoneum
- ureters, urinary bladder, urethra, rectum
- male: prostate, ductus deferens, seminal vesicles, ejaculatory ducts, bulbourethral glands (below pelvic diaphragm)
- female: ovaries, uterine tubes, uterus, vagina
ureters
- upper half in abs (retroperitoneal), lower half in pelvis
- males: crossed by DD, btwn that and peritoneum
- females: crossed by uterine art, post part of ovarian fossa
- pierce post-lat edge of bladder, go oblique thru muscular wall
- when ligating uterine tube, watch for ureter
Ureter blood supply
- any art they pass
- renal, gonadal, common + internal iliac, vesical, uterine
- variation from anastomoses
Ureter Innervation + lymphatics
- innervation = ureteric nerves from renal, aortic, sup/inf hypogastric plexus (T10-L1), symp + parasymp
- lymphatics => renal vessels, lateral aortic + lumbar nodes, common/int/ext iliac nodes
Bladder
- urine storage
- over pubic symph when full (suprapubic lithotomy)
- prone to rupture in ab trauma + ant. pelvic fracture
- young more prone (not protected)
- cystitis = bladder infection, females more prone (short urethra)
Bladder Surface
- apex, base/fundus/, int lat surface, neck
- trigone -> appears smooth due to embryology, covered w/mucous layer
- top = urethral crest
- internal urethral orifice + sphincter (prevents backflow of semen into bladder)
Bladder stabilization
- median umbilical lig -> attaches bladder to umbilicus
- false ligs -> folds of peritoneum
- thickening of endopelvic fascia (pubovescial = female, puboprostatic = male)
- rectovesical lig = posterior
Internal Surface of Bladder
- Internal mucous layer, folds when contracted
- muscle = detrusor (smooth) - expands when full, contracts by parasymp stim (pelvic splanchnics)
Blood Supply of Male Urethra
inf vesical, mid rectal, int. pudendal art
Prostatic Urethra
- Urethral crest -> seminal colliculus vesicles (have ejaculatory ducts + prostatic utricle)
female urethra (3)
- smaller than male (cystitis)
- From bladder -> DP pouch/mem -> vestibule ant to vag opening
- urethral glands + Paraurethral ducts -> external urethra margin
Male reproductive tract/path of semen (8)
- testes -> seminiferous tubules -> epididymis -> ductus/vas deferens -> seminal vesicle -> ejaculatory duct -> urethra -> penis
Testes (4)
- from post ab wall -> ab canal -> outside body
- lymph drainage = lumbar lymph nodes
- tissue covering = ext/int spermatic fascia, cremaster muscle
- blood supply = testicular a/v, pampiniform plexus
Ductus (vas) deferens (5)
- cont. w/epididymis, small lumen, thick walls, covered w/peritoneum
- in scrotum, tortuous, then straight
- traverses ing canal; at deep ring, separates from sperm cord, enters true pelvis
- crosses over ureter btwn bladder (post to it) & rectum
- enlarges (ampulla), joins seminal vesicle duct to form ejaculatory duct
Seminal Vesicles (3)
- coiled tube, prox end constricts, joins DD to form ejaculatory duct
- Provides most semen, joins sperm from DD
- Blood supply: inf vesicle + mid rectal arts (w/veins)
Ejaculatory duct (2)
= union of seminal vesicle ducts + ductus deferens
- Terminal opening of seminal colliculus
Bulbourethral glands (3)
= 2 glands in DP pouch
- go thru perineal mem, drain to spongy urethra
- Pre semen – cleans out leftovers in urethra before semen comes thru
Prostate (6)
= glandular, fibromuscular, has lobes, makes 20% semen
- urethral crest – down from trigone
- seminal colliculus – bump in middle
- prostatic utricle – from vaginal embryology
- ejaculatory duct openings – below utricle, on each side
- prostatic sinus – sides of colliculus; prost duct openings
Prostate Blood Supply/Venous Drainage (2)
- Blood supply: inf vesical, int pudendal, mid rectal arts
- Venous: prostatic venous, vesicular, internal vertebral plexus
Prostatic Changes (5)
- 45-50yrs -> BPH = urine flow blocked in prostatic urethra
- malignant, nodular = prost cancer (= prostatectomy)
- DRE + serum level test for PSA (inc in cancer)
- Prostatectomy - preserve prost nerve plexus (impotence)
- If resecting plexus, do sural n. grafts
Female Viscera (6)
- ovaries, uterine tubes, uterus, cervix, vagina, greater vestibular glands
Ovaries (3)
- in true pelvis, develop like testes, ovulate oocytes into peritoneal cavity
- Oocytes -> uterine tube -> uterus
- Held in place by:
○ ovarian lig
○ suspensory lig – holds ovary to wall
○ Mesovarium – part of broad lig
Ovaries Blood Supply/Nerves (2)
- Blood Supply: ovarian arts + veins (R to vena cava, L to renal vein, drainage same as testicular vein)
- Nerves: pelvic splanchnics -> parasymp
Uterus (3)
- in true pelvis
- Blastocytes implant here -> when fertilized, implant in wall
- Enlarges in preggos, atrophies in old age (dec hormones)
Uterus Parts (4)
○ Fundus - top, above opening of uterine tubes
○ Body - btwn layers of peritoneum
○ Isthmus - btwn body and cervix
○ Cervix - Surrounds internal opening
3 layers of Uterus Wall
- Perimetrium: peritoneum + areolar tissue
- Myometrium: most of wall, smooth muscle
- Endometrium: inner mucous coat, epithelium
Cervix, External Os, Fornix (5)
- Cervix - surrounds int os (near isthmus)
- External os -> vagina
- Fornix - recess around protruding cervix
- Uterus anteverted + anteflexed = on top of bladder
- If retroverted + retroflexed uterus => implantation + fertility problems
Uterus Support (5)
- thickenings of endopelvic fascia (transverse cervical + uterosacral ligs)
- Levator ani
- UGD
- Other pelvic organs (esp. bladder)
- Uterine ligs
Transverse cervical (cardinal) ligs, uterosacral ligs (3)
- transverse cervical (cardinal) ligs: cervix & lat fornices of vagina to lat pelvic wall
- uterosacral ligs (supportive): sides of cervix to mid sacrum; palpable on rectal exam
- Homologues of gubernaculum
○ Round Lig: uterus -> labia majora
○ Ovarian Lig: ovary -> uterus
Broad Lig (5)
- peritoneum over uterus + adnexa in pelvis
- Mesosalpinx = suspends uterine tube
- Mesovarium = suspends ovary
- Mesometrium = main part below ovary + uterine tube
- Suspensory lig of ovary: ovarian vessels covered w/peritoneum
Blood Supply/Venous Drainage to Uterus (3)
- uterine art (some from ovarian + vaginal a.)
- Uterus gives blood to fetus (needs a lot) -> inc blood in preggos
- Venous Drainage: -> uterine plexus -> internal iliac veins
Uterus Lymphatics (4)
- Fundus - lumbar, external iliac
- Body - external iliac
- Cervix - internal iliac, sacral
- Area where uterine tubes join uterus has lymph drainage -> follows round lig, drains to superficial ing. nodes
Uterus Innervation (3)
- uterovaginal plexus
- parasymp from S2-S4
- symp from T12-L2 lumbar splanchnics, intermesenteric, hypogastric plexuses)
Vagina (3)
= fibromuscular tube from cervix to vestibule (btwn labia minora), walls in contact w/each other
- sup end of vagina surrounds cervix, extends sup = ant/post/lat fornix
- post. fornix related to rectouterine pouch
Pt w/peritonitis infection (3)
- do culdocentesis to check for abnormal fluid in pouch of Douglas
- Inferiorly -> somatic info from pudendal nerve – feel pain
- Superiorly -> viscera, don’t feel pain – don’t need anesthesia when removing fluid
Vaginal Sphincters (4)
- Pubovaginalis (part of levator ani)
- urethrovaginal sphincter (smooth muscle)
- Bulbospongiosus
- external urethral sphincter
Vaginal Blood Supply + Venous Drainage (2)
- Blood supply: Uterine + Vag a. (overlap), mid rectal & int pudendal a.
- Drainage: internal iliac vein
Vaginal lymphatics + nerves of upper 2/3 (2)
- lymph - int/ext. iliac
- visceral innervation: uterovaginal plexus (from inf. Hypogastric plexus) -> parasymp/symp & afferent fibers
Uterine Tubes (4)
- 3-layered structure (serosa, muscle and epithelium).
- hollow tubes -> peritoneal cavity -> uterus
- convey oocyte to uterus and sperm to oocyte
- fimbria brings floating oocyte into uterine tube and thru it via peristalsis
Uterine Tube Parts (4)
- infundibulum – has fimbriae
- ampulla
- isthmus
- uterine portion
Uterine Tube Blood Supply/drainage/lymph (2)
- Blood supply/drainage: ovarian + uterine arteries/veins
- Lymph: lumbar nodes
Peritonitis
more in females due to continuity of vagina/uterus w/ab cavity
Ectopic pregnancy (5)
- outside of uterine cavity if oocyte fertilized
- Tubal – in uterine tube (not viable -> insufficient space + blood supply)
- Abdominal – in ant. ab wall = “stone baby” = Lithopedion
○ Ectopic fetus detected by immune sys
○ Sometimes viable, present as normal - Ovarian – ovary itself
- Cervical – moves too far, in cervix
Rectum (3)
= Cont w/sigmoid colon at S2/S3 (lower end of sigmoid mesocolon) + w/anal canal (passes thru pelvic diaph)
- Anorectal junction in front of tip of coccyx; 80 degree turn
- Lower part dilated (ampulla) -> no sacculation/appendices/mesentery (only sup front/sides covered in peritoneum)
Rectum Blood Supply (3)
- Sup (inf mesentery)/mid. (inf vesical-male; uterine-female)/inf. (int pudendal a) rectal arts + veins
- portal (sup) + caval (mid./inf) systems
Rectum Innervation
- Hindgut innervation
- Symp: lumbar splanchnics/sup. hypogastric plexus
- Parasymp: pelvic splanchnics/inf. hypogastric plexus
Failure of Hammock: Prolapse of Pelvic Viscera
- potential from childbirth or trauma
- Cystocele = bladder prolapse via vagina
- Uterine prolapse = end of cervix, prolapse via vagina
- Rectocele = rectal prolapse
Perineum
- inf to pelvic diaphragm + urogenital hiatus
- same boundaries as pelvic outlet, btwn legs externally, shallow compt. internally
- floor = skin & fascia; roof = pelvic diaphragm + fascia
- divided into ant urogenital triangle + post anal triangle
Deep perineal pouch (aka UGD)
- Superior to perineal mem
- Reinforces pelvic diaphragm, supports pelvic viscera
- Further outside = superficial perineal pouch
Contents of 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)
Male Urethra: Preprostatic
short, from base of bladder, surrounded by internal urethral sphincter
Male Urethra: Prostatic
- length of prostate, widest/most dilatable part
- closer to ant prostate
- gets ejaculatory/prostatic duct openings
Male Urethra: Membranous
- in DP pouch (UGD), surrounded by external urethral sphincter
Male Urethra: Spongy
- in corpus spongiosum, longest, widens => navicular fossa
- openings of bulbourethral glands
- out to external urethral orifice, surrounded by erectile tissue
Prostate Innervation/Lymph
- Innervation: pelvic splanchnic nerves (parasymp) + inferior hypogastric plexus (symp)
- S2-S4 (also to bladder, rectum, penis)
- Lymph: internal iliac + sacral nodes
Vaginal lymphatics + nerves of lower 1/3 (3)
- Lymphatics: superficial inguinal
- Innervation: somatic innervation: from deep perineal branch of Pudendal n. -> symp + somatic afferent fibers
- NO parasymp (only part of vagina sensitive to touch and temperature)
Rectum Cont
- Teniae coli – spread out to form single layer
- 3 perm transverse rectal folds/valves of Houston
- Upper part of rectum = fecal reservoir
