Anatomy of the Bony Pelvis Flashcards
What is part of the bony pelvis but not part of the pelvic girdle?
coccyx
What type of cartilage makes up the acetabulum in children and adolescents?
hyaline-triradiate cartilage
What is the largest bone of the hips?
ilium
What forms the pelvic inlet?
sacral promontory; ilium; superior pubic ramus and pubic symphysis
What forms the pelvic outlet?
pubic symphysis; ischiopubic ramus; ischial tuberosities; sacrotuberous ligaments; coccyx
Where does the pelvic cavity lie?
between the pelvic inlet and pelvic floor
Where does the inguinal ligament attach?
between ASIS and pubic tubercle
Where are the ischial spines palpable on vaginal examination?
approx. 4 and 8 o clock positions
What is the point of palpating the ischial spines on vaginal exam?
used during lacbour as a measure of how far along
What does the sacrospinous ligament attach between?
sacrum and ischial spine
What does the sacrotuberous ligament attach between?
sacrum and ischial tuberosity
What is the function of the sacrotuberous and sacrospinous ligaments?
ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebral column
Where do the obturator nerves and vessels travel in the obturator foramen?
obturator canal-superiorly in the foramen
What are the differences between the male and female pelvises?
AP and transverse diameters of F are larger at inlet and outlet; subpubic angle in F is greater; pelvic cavity is much shallower in F; bones are thinner and gracile in F; greater sacral promontory in M; bigger greater sciatic notch in F; M inlet is heart shaped not round as in F
What is moulding?
movement of one bone over another to allow the fetal head to pass through the pelvic
What allows moulding to occur?
sutures and fontanelles
Where is the posterior fontanelle found?
at the intersection between the sagittal and lambdoid sutures
Where is the anterior fontanelle found?
intersection between sagittal and coronal sutures
What is the vertex?
area of fetal skull outlined by the anterior and posterior fontanelles and parietal eminences
What is the difference between the biparietal and occipitofrontal diameters in fetal skull?
occipitofrontal diameter is longer; eg fetal head is longer than it is wide
What is the distance of the fetal head from the ischial spines known as ?
the station
What is the diameters of the transverse and AP at hte pelvic inlet of F?
transverse is wider
How should the fetus ideally enter the pelvic cavity?
head in transverse position as occipitofrontal is longer and so is transverse diameter of pelvis
What is the dimeters of the transverse and AP at the pevlic outlet in F?
AP is bigger than transverse
What should happen to the fetal head when descending through the pelvic cavity?
rotate and be in a flexed position
How should baby ideally leave the pelvic cavity?
occipitoanterior position
How should the fetal head be during delivery?
in extension
What type of joint is the anterior sacro-iliac joint?
synovial
what type of joint is the posterior sacro-iliac joint?
syndesmosis
What type of joint is the pubic symphysis?
secondary cartilaginous joint
