Lec. 4: Bones & Jts of Pelvic Girdle Flashcards
which organs lie inside the true pelvis
urinary bladder, the colon, and the internal reproductive organs
bones that make up the pelvis
2 coxal bones, the sacrum, and the coccyx
the coxal bones are made up of which 3 bones each
Ilium, pubis, and Ischium
the pelvic brim separates which portions of the pelvis
SUP and INF
the circle of the pelvic brim is made up of what 4 bony landmarks of the coxal bones and what 2 of the sacrum
BONY LANDMARKS ON COXAL BONES: arcuate lines, iliopubic eminences, SUP pubic rami (more specifically the pecten pubis on BL rami), symphysis pubis
BONY LANDMARKS ON SACRUM: margin of ala (2) and promontory
what separates the pelvis into a SUP and INF portions
pelvic brim
where is the greater pelvis located in relation to the pelvic brim
SUP to it
why is the greater pelvis considered to be a “false” pelvis
b/c it primarily contains organs of the abdomen except a full bladder or pregnant uterus
the lesser pelvis is the “true” pelvis as it lies below the ____ ____ and surrounds the ____ ____.
pelvic brim, pelvic cavity
superior brim of the lesser pelvis
pelvic inlet
inferior opening of the lesser pelvis
pelvic outlet
if looking at a sagittal section of pelvis, what’re the landmarks that represent the points of both the pelvic inlet and outlet
inlet: SUP portion of pubic symphysis and promontory
outlet: INF portion of pubic symphysis and tip of tailbone (coccyx)
how does the general structure of the pelvis differ b/w men and women
men: more massive w/ prominent processes
women: more delicate w/ less prominent processes
how do the pelvic inlets and outlets of the pelvis differ b/w men and women
men: inlet; heart shaped, outlet; narrower and oval
women: inlet; oval-shaped, outlet; wider and round (to allow for baby to pass through)
how does the obturator foramen, acetabulum, symphysis pubis, and pubic arch differ b/w men and women
men: obturator foramen is round, acetabulum faces LAT, pubic symphysis is deeper and longer, and pubic arch is narrow (<90 degrees)
women: obturator foramen is oval, acetabulum faces more ANT, symphysis pubis is shallower and shorter, and the pubic arch is wider (>90 degrees)
5 roles of the pelvis
- supportive base for vertebral column
- transmits force of trunk, head, arms downward and transmits forces from lower limbs upward
- provides large area for muscle attachment
- contains and protects pelvic organs
- attachment point for the lower extremity
primary func of SI jt
to transmit the weight of the body from the vertebral body to the bony pelvis
mvts permitted, art. surfaces, and classification of SI jt
mvts permitted: smooth gliding mvt, nutation (ANT sacral ROT), and counternutation (POST sacral ROT)
art. surfaces: auricular surfaces of sacrum and ilium (ilium has fibrocartilage and sacrum has hyaline cartilage on jt surfaces)
class.: inferior 2/3: non-axial plane synovial (functionally diarthroidal)
superior 1/3: fibrous syndesmosis (functionally amphiarthroidal)
motion at the SI jt is involuntary, T or F
T; b/c no mms cross this jt alone, mvt at this jt occurs during motion at adjacent jts
SI jt ligs (6)
capsule, interosseous sacroiliac, ANT and POST sacroiliac, iliolumbar, sacrospinous, sacrotuberous
feats of capsule of SI jt
surrounds INF diarthroidal part of jt and separates it from SUP 1/3 of the amphiarthroidal part of jt
interosseous sacroiliac feats
connects adjacent bones w/in the SUP amphiarthroidal 1/3 of SI jt
ANT and POST SI lig
suspends the sacrum from the ilia and limits counternutation of sacrum. Key in shock absorption
iliolumbar lig feat
stabilizes lower L/SP+ on sacrum
sacrospinous lig feat
limits sacral nutation
sacrotuberous lig feat
limits sacral nutation, often continuous with biceps femoris tendon
mvts permitted, art. surfaces, and classification of pubic symphysis jt
mvts permitted: sm. amounts of gliding occur with mvt of the sacrum, vertebral column, and lower extremities
art. surfaces: symphysial surface of pubis (covered in hyaline cartilage) and fibrocartilaginous disc
class.: symphyseal jt, functionally amphiarthroidal
2 pubic symphysis ligs and their funcs.
-SUP pubic: limits SUP shearing of pubis bilaterally
-INF pubic (arcuate): limits INF shearing of pubis bilaterally
art. surfaces and classification of coxofemoral (hip) jt
art. surfaces: lunate surface of acetabulum w/ femoral head
class.: multiaxial ball and socket, synovial
mvts at coxofemoral jt
FLEX/EXT: MED/LAT axis, sagittal, full hip flexion limited by hamstring length when knee is in position of full extension
(active insufficiency)
ABD/ADD: AP axis, frontal
INT/EXT ROT: mechanical axis, no plane
CIRCUMDUCTION: combo of all mvts
feats of the coxofemoral jt capsule (3)
-strong but loose collar around femoral neck
-attaches from periphery of acetabular margin to intertrochanteric line anteriorly, and to middle femoral neck posteriorly
-hip jt is very strong even w/out supporting ligs and mms
why is the hip jt so strong
b/c w/in the capsule there is ~150psi of negative pressure creating a vacuum
a ligament thats a thickening of the hip jt capsule whose fibers encircle femoral NK
zona orbicularis
3 feats of the hip jt labrum
-deepens the socket for increased congruency (like glenoid labrum)
-attaches to acetabular margin and lunate surface
-fibrocartilaginous
hip jt lig that limits hyperextension, prevents posterior pelvic tilt during relaxed standing; strongest of the three
iliofemoral (Y lig)
hip jt lig that limits hyperextension, abduction and medial rotation; also limits hyperflexion; weakest of the three
ischiofemoral
hip jt lig that limits hyperextension, lateral rotation and abduction
pubofemoral
bursa that’s anterior to the iliofemoral and pubofemoral ligaments, posterior to iliopsoas tendon
iliopectineal bursa
bursa that’s superficial and lateral to greater trochanter, deep to gluteus medius muscle
deep trochanteric bursa
bursa that’s superficial and lateral to greater trochanter, superficial to gluteus medius insertion
superficial trochanteric bursa
