Pelvic/Perineal Osteology Flashcards
what makes up the pelvic brim
arcuate line, pectin pubis, sacral promontory
Pelvic shapes common in male vs female
- uncommon in both?
- safety of child birth
Anrdoid is classically male, gynecoid female, anthropid in some black females.
platypelloid uncommon in both.
platypelloid or markedly android funnel shaped presents hazard to vaginal delivery
Spondylolysis of L5/S1
Spondylolisthesis of L5/S1
spondylolysis is fracture of posterior projection of vertebral body so articular, transverse, spinal processes are separated from the body
-Spondylolisthesis would occur if defect in L5 were bilateral, body of L5 might slide anteriorly and overlap the promontory. reduces the AP diameter (bad for child birth), and can compress spinal nerves.
- True obstetrical conjugate
- diagnoal conjugatge, why its used, ideal distance
- interspinous distance
true conjugate is middle of sacral promontory to posterosuperior margin of the pubic symphysis
diagonal conjugate used because bladder in way for true
interspinous distance is narrowest part of pelvic canal through which a babys head will pass.
Anteroposterior compression of pelvis produces what type of fracture
fractures of pubic rami
Fracture of pubo-obturator area poses complications of what?
relationship to urinary bladder/urethra which may rupture or be torn
What happens to the pelvic ligaments during pregnancy?
-which biomolecules
increased levels of sex hormones and hormone relaxin causes pelvic ligaments to relax during latter half of pregnancy. relaxation occurs at si joint and pubic symphysis.
what type of joint is L5/S1
Intervertebral joint: symphysis
Zygopophyseal joint: planar synovial
the lumbosacral L is most like what other ligament?
intertransverse ligament
Sacroiliac joint types
- anteriorly?
- posteriorly?
Compound joint overall
anteriorly between auricular surface of sacrum and articular surface of the ilium it is planar synovial
posteriorly between the sacral and ishial tuberosisities it is fibrous synesmosis
Posterior sacroiliac L
- long origin, insertion
- short origin, insertion
- long posterior sacroiliac L is two bands that come from the PSIS and medial sacral crest of S3/S4 and then inserts and blends w/ sacrotuberous L.
- Short originates from the median Sacral Crest of S1/S2 and inserts onto the posterior surface of the iliac crest and iliac tuberosity
joint type of sacrococcygeal
symphysis
make sure to note rectovesical pouch
Pelvic fascia organization
Parietal pelvic fascia lines muscular walls of what?
of the pelvis: obturator internus M., Piriformis M., Levator Ani Ms., and the Coccygeus M.
Obturator fascia:
- lines what?
- continuous superiorly with what?
- forms walls of?
- forms tendinous arch of?
lines the pelvic side of the obturator internus M., continuous superiorly with transversalis fascia, forms the walls of the pudendal canal, forms the tendinous arch of the Levator Ani Ms
Tendinous arch of pelvic fascia in males vs females
- puboprostatic L is anterior part in males, pubovesicle L is anterior in females
- sacrogenital L is posterior in both, but can be broken down into rectoprostatic in males, and uterosacral* in females
Loose endo fascia
- fat filled potential spaces
- name them/describe them
Retropubic space: between pubis and urinary bladder, continuous paravesical space
Paravesical space: between obturator fascia and anterior part of hypogastric sheath
Pelvirectal space: surrounds rectum, separated into a/p parts by Lateral rectal L
Retrorectal Space: presacral space between sacrum and rectum, continous anterolaterally w/ pelvirectal space
Condensed Endopelvic fascia:
-why condensed, what does it do?
increased density of collagen and elastic fibers, responsible for compartmentalizing the loose endopelvic fascia
Hypogastric sheath:
- type of fascia
- purpose
- three parts
thick band of condensed fascia, conduit for nerves and vessels from lateral pelvic wall to pelvic viscera
Anterior: Lateral L of the bladder- extension of the hypogastric sheath to the urinary bladder
Middle: in males the rectovesical septum between the rectum and urinary bladder
in females it is the *transverse cervical ligament* or the *cardinal ligament*, which extends the hypogastric sheath to the cevix of the uterus
lateral rectal L is posterior aspect of sheath
Quadrangular space of perineum:
what are the points?
how is it devided further
anterior is pubic symphysis, coccyx posterior, ischial tubs laterally.
line can be drawn between the two ischial tuberosisites… get two triangles.
urogenital anterior, anal triangle posterior
Contents of the anal triangle
ischioanal fossa (around the wall of the anal canal, inferior to pelvic diaphragm, allows for expansion of anal canal during defecation
pudendal canal, made of obturator fascia, transmits the internal pudendal A, V, and Pudendal N.
Urogenital triangle contents
perineal membrane, superficial perineal fascia, deep perineal fascia, superficial perineal pouch, deep perineal pouch
Perineal membrane:
what does it cover?
extends between the two sides of the pubic arch, covers the anterior portion of the pelvic aperture
Superficial perineal fascia:
- continuous with?
- fatty part in females vs males
- membranous part
superficial perineal fascia is continuous with the supeficial fascia of the abdomen, and has a fatty and membranous component
- fatty component is more superficial and in women forms the fatty layers of the labia majora and the mons pubis, in males this component is replaced by penis/scrotum
- the membranous part is more deep and forms the dartos fascia of the penis and scrotum
Deep perineal fascia
female vs male
in females exists primarily as the perineal membrane, in the male it makes up the deep fascia of the penis and the perineal membrane
Superficial perineal pouch:
- location
- contents male vs female
located between membranous superficial perineal fascia and the perineal membrane
- in males: bulb and crura of the penis, superficial perineal muscles, proximal spongy urethra, branches of the internal pudendal A./V., and of the pudendal N.
- in females: crura of the clitoris, bulbs of the vestibule, superficial perineal muscles, greater vestibular glands, branches of the internal pudendal A/V, and the pudendal N.
Deep perineal pouch:
- location
- contents male vs female
opens superiorly, lies inferoanteriorly to the urinary bladder
- males contains membranous urethra, muscles of the urogenital diaphragm, bulbourethral glands
- in the female it contains muscles of urogenital diaphragm
