Pelvic Girdle, Pelvic Cavity, and Neurovascular Structures of Pelvis Flashcards
gynecoid pelvis
normal female type
- rounded oval shape
- wide transverse diameter
platypelloid or android pelvis
masculine or funnel shaped, respectively
pelvis and forensics
pelvic girdle commonly used to differentiate b/w sexes
true conjugate
minimum diameter of lesser pelvis - from middle of sacral promontory to the poterosuperior margin of the pubic symphysis = narrowest fixed distance through which baby’s head must go
why can’t true conjugate be measured directly?
bladder in the way
diagonal conjugate measurement
palpating the sacral promontory w/ the tip of the middle finger, using the other hand to mark the level of the inferior margin of the pubic symphysis on the examining hand
how is true conjugate measured from diagonal conjugate
distance b/w tip of index finger and the marked level of the pubic symphysis - should be 11 cm or more
narrowest part of the pelvic canal
interspinous distance - b/w ischial spines
pelvic canal
passageway through the pelvic inlet, lesser pelvis, and pelvis outlet
how is it determined if the subpubic angle is wide enough for passage of average fetal head at full term?
if three fingers can be inserted into vagina side by side
what type of trauma commonly produces fractures of the pubic rami?
anteroposterior compression of the pelvis - during crush accidents
what can be fractured when pelvis is compressed laterally?
acetabula and ilia
fractures of the bony pelvic ring
almost always multiple fractures or a fracture combined with a joint dislocation
what are the weak areas of the pelvis where fractures commonly occur?
- acetabula or surrounding area
- pubic rami
- region of sacro-iliac joints
- alae of the ilium
what causes the pelvic ligaments to relax during the latter half of pregnancy?
- increased levels of sex hormones
- hormone relaxin
what does relaxation of the pelvic ligaments allow for?
increased movement at the pelvic joints to facilitate passage of the fetus through the pelvic canal
what does relaxation of the sacro-iliac ligaments cause?
- less effective interlocking mechanism of the sacro-iliac joint
- greater rotation of pelvis -> lordosis
parturition
childbirth
what may be injured during childbirth?
- perineum
- levator ani
- ligaments of the pelvic fascia
what muscles are torn most often in childbirth?
main and most medial parts of the levator ani - pubococcygeus and puborectalis
urinary stress incontinence
dribbling of urine when intra-abdominal pressure is raised during coughing and lifting - can occur due to childbirth
prenatal training
attempts to train woman to learn how to relax voluntarily the muscles of the pelvic floor while simultaneously increasing intra-abdominal pressure through contraction of the diaphragm and anterolateral abdominal wall muscles
hysterectomy
excision of uterus
what may be injured during ligation of uterine artery during hysterectomy?
ureter
ovariectomy
excision of ovary
what may be injured during ligation of ovarian artery during ovariectomy?
ureter
hemostasis
arrest of bleeding
collateral pathways to the internal iliac artery
include these pairs of anastamoses:
- lumbar and iliolumbar
- median sacral and lateral sacral
- superior rectal and middle rectal
- inferior gluteal and profunda femoris
what pelvic nerve is vulnerable to injury during surgery?
obturator nerve - injury may cause painful spasms of thigh adductors and sensory deficits in medial thigh
