5 LE Pelvis + Perineum Flashcards
pelvis
part of body surrounded by pelvic girdle
- lies below + is continuous w/ abdomen
- part of birth canal
anatomical position of pelvis
a bowl that is tilted forward
- pubic symphysis + ASIS are in same vertical plane
features of the pelvis
greater (false) pelvis
lesser (true) pelvis
greater pelvis
“false pelvis”
superior to pelvic brim
greater pelvis FCN
protect + support inferior abdominal viscera (shield)
lesser pelvis
“less pelvis”
inferior to pelvic brim
- pelvic inlet/pelvic outlet = tip of coccyx
pelvic cavity
between brim + pelvic outlet
lesser pelvis contains
distal GI tract (rectum/anus)
urinary tract (bladder)
reproductive organs
male pelvis
thicker bones + heavy
more prominent markings
smaller pelvis
deep greater pelvis
narrow/deep, tapering lesser pelvis
(pelvic inlet - superior) heart-shaped, narrow
(pelvic outlet - inferior) comparatively small
(pubic arch) narrow
female pelvis
thin + light bones
less prominent markings
larger pelvis
shallow greater pelvis
narrow/deep, tapering lesser greater pelvis
(pelvic inlet - superior) oval + rounded, wide
(pelvic outlet - inferior) comparatively large
(pubic arch) wide >80˚
oval obturator foramen
small acetebulum
(greater sciatic notch) almost 90˚
flat, wide, short sacrum
everted ischial tuberosities
types of pelves
android
anthropoid
gynecoid
platypeliod
android pelvis
heart-shaped pelvis
- typically male
- 20% of white females
**android = robot, robot has no heart
anthropoid pelvis
oval-shaped pelvis
- typically male
- common in black females
**ant has oval head like anthropoid
gynecoid pelvis
round-shaped pelvis
- typically female
- 50% of females
- best for childbirth
platypelloid pelvis
pelvis that is flat by sacrum
- rare
- only 3% of females
- causes most problems during childbirth
**platypus has flat tail… platypelloid pelvis has flat top
pelvic walls
anterior wall
lateral walls
posterior wall
anterior pelvic wal
pubic bones
rami
symphysis
lateral pelvic wall
hipbone
obturator membrane
obturator internus muscle
posterior pelvic wall
sacrum coccyx piriformis muscle sacrotuberous ligament sacrospinous ligament
pelvic floor
formed by the bowl / funnel-shpaed pelvic diaphragm
- located btwn lesser pelvis + perineum
pelvic diaphragm
coccygeas + levator ani
pelvic floor FCN
(1) support pelvic viscera
(2) counteract increase intra-abdominal pressure from coughing, sneezing, exerted exhale
injury to pelvic floor
prominent during childbirth
- may cause prolapse of vagina/rectum (organ comes out of hole when not supposed to)
- may cause urinary + fecal incontinence (unable to hold it in)
**kegel exercises for prevention
muscles of the levator ani
puborectalis “looper around pooper”
pubococcygeous
iliococcygeous
**hay 5 but only need to know 3
levator ani
O: pubic + pelvic fascia + ischial spine
I: external anal sphincter, coccyx, central perineal tendon
A: support pelvic viscera + counteract increase intra-abdominal pressure + maintain urinary fecal continence
N: pudendal nerve
coccygeus muscle
“ischiococcygeous”
O: ischial spine
I: sacrum + coccyx
A: support pelvic viscera + counteract increase intra-abdominal pressure + flex coccyx
N: pudendal nerve
perineum
shallow compartment below pelvic diaphragm btwn thighs
- abducted thighs = diamond-shaped area
perineum boundaries
(front) pubic symphysis
(back) tip of coccyx
ischial tuberosities
perineum triangles (2)
(front) urogential triangle
(back) anal triagnle
anal triangle
(perineum) pierces pelvic diaphragm
- surrounded by internal/external anal sphincters
- continuation of pelvic floor
ischioanal (ischiorectal) fossae
wedge-shaped spaces btwn skin + pelvic diaphragm
- contains fat
- passage for nerves + vessels
- avascular (hard to treat infections here w/ antibodies)
pudendeal canal
sheath of CT that holds VAN
- part of anal triangle
- horizontal passageway
- lateral wall ischioanal fossa
- internal pudendal vessels, pudendal nerve + nerve to obturator internus enter @ lesser sciatic notch
- supplies, drains y innervates most of perineum
pudendal nerve block
numbs S2-S4 dermatomes, most of perineum y 25% of vagina
- older method
- used in childbirth
- not used as much
- does not numb uterus, cervix y 75% of upper vagina
- still feel contractions
- does not effect baby
- used for episiotomy (vaginal repair)
fascial coverings of the urogential triangle
superficial fascia
deep fascia
superficial fascia (urogenital triangle)
fatty fascia
- membranous (perineal) fascia
deep fascia (urogenital triangle)
perineal membrane
- anchors external genitalia (penis/scrotum + vulva)
urogenital triangle
part of perineum
- perineal muscles
- external genitalia
- supplied by internal pudendal artery + internal pudental vein + pudendal nerve
male external genitalia
penis
scrotum
distal urethra
female external genitalia
vulva/pudendum clitoris mons pubis labia vaginal opening vestibular glands
superficial perineal muscles (3)
superficial transverse perineal
bulbospongiosus
ischiocavernosus
perinal body
central part of attachment for sacral muscles between
superficial transverse perinal
superficial perineal muscles
A: resist increase intra-abdominal pressure + support pelvic floor + fix perineal body
N: pudendal nerve
bulbospongiosus
superficial perineal muscle
A: support pelvic floor
(males) assist w/ erection, ejaculations y nicturition (urination)
(females) control vaginal opening + assist in clitoral erection
N: pudendal nerve
ischiocavernosus
superficial perineal muscle
A: compress erectile tissue to help maintain erection
N: pudendal nerve
deep perineal muscles (2)
deep transverse perineal
external urethral sphincter
deep transverse perineal
deep perineal muscle
A: resist increase intra-abdominal pressure + support pelvic floor + fix perineal body
N: pudendal nerve
external urethral spincter
deep perineal muscle
A: compress urethra to maintain urinary continence
N: pudendal nerve
