Pelvis and perineum Flashcards
what is the bony pelvis formed of?
hip bones and sacrum
three hip bones
ileum, ischium and pubis
when do the hip bones fuse?
adolescence
where do the hip bones fuse?
acetabulum
what forms the pelvic inlet?
posterior border- sacral promontory
lateral border- iliopectineal line
anterior border- pubic symphysis
more detailed pelvic inlet
posterior- promontory of sacrum, margin of ala
lateral- arcuate line of ileum
anterior- pectineal line of pubis and pubic crest
why is the size of the pelvic inlet important?
foetal head must transverse the aperture during partuition
pelvic outlet
posterior- tip of coccyx
lateral- ischial tuberosity and the sacrotuberous ligament (ischiopubic rami)
anterior border- pubic arch
pelvic walls definition
urogenital and pelvic diaphragm
superficial muscles such as the glutes
hip bones, sacrum and coccyx and associated ligaments
deep muscles, blood vesels, nerves and a peritoneum
synonym for pelvic floor
pelvic diaphragm
what forms the pelvic floor?
skeletal muscle supplied by somatic nerves and associated connective tissue
function of pelvic floor
maintains and supports the position of pelvic viscera
important tole in anal continence and defecation
structure of pelvic floor
gutter shape
right and left levator ani - pubococcygeus and iliococcygeus
right and left coccygeus muscles
pelvic organs
bladder, uterus, vagina and rectum
location of pelvic organs
bladder- anterior, posterior to pubis
uterus- posterior to bladder, anterior to rectum, anteflexed, anteverted
rectum- posterior to uterus
what is found directly beneath the pelvic floor?
perineal membrane
what is the perineal membrane
strong connective tissue that stretches across the urogenital triangle between the ischiopubic rami
different regions of the perineal membrane
separated from pubic symphysis by a small gap that allows veins from the penis and clitoris to pass
central, posterior part continuous with the perineal body
where is the perineal body located in men and women?
men- midline between deep and superficial perineal spaces anteriorly and anal canal posteriorly
women- midline, between the lower end of the vagina and anal canal
perineal body structure + function
small, wedge shaped mass of fibrous tissue
attachments to perineal membrane, levator ani and perineal muscles
ensures integrity of perineum and pelvic floor
what is the perineum separated into?
Anal triangle and urogenital triangle by a line separating the two ischial tuberosities
does the anal triangle have a perineal membrane?
no
