Pelvis and Perineum, Snell Flashcards
Pelvis is divided into 2 parts by the
Pelvic brim
Pelvic brim is formed by (3)
1) Sacral promontory
2) Iliopectineal line
3) Symphysis pubis
Above the pelvic brim
False pelvis
Below the pelvic brim
True pelvis
4 bones of bony pelvis
1) 2 hip bones
2) Sacrum
3) Coccyx
Pelvic inlet is aka
Pelvic brim
Boundaries of pelvic outlet (3)
1) Coccyx
2) Ischial tuberosities
3) Pubic arch
Main function of SI joint
Transmit weight of body from vertebral column to bony pelvis
SI joint: Type of joint
Synovial
Symphysis pubis: Type of joint
Cartilaginous
T/F Great deal of movement is possible at the sacrococcygeal joint
T
Imaginary line joining the central points of the AP diameters of the inlet and outlet
Axis of pelvis
Curved course taken by the baby’s head as it descends through the pelvis during childbirth
Axis of pelvis
Distance between lower margin of symphysis pubis and sacral promontory
Diagonal conjugate
Normal length of diagonal conjugate
13 cm
Normal distance between 2 ischial tuberosities
10cm
Shallowest wall of pelvis
Anterior
Anterior pelvic wall is formed by (2)
1) Pubic bones
2) Symphysis pubis
Posterior pelvic wall is formed by
1) Sacrum
2) Coccyx
3) Piriformis
Lateral pelvic wall is composed of (4)
1) Hip bone below inlet
2) Obturator membrane
3) Obturator internus
4) Sacrospinous and sacrotuberous ligament
Structure that almost completely closes the obturator foramen
Obturator membrane
Small gap in the obturator membrane
Obturator canal
Obturator canal transmits
Obturator nerve and vessels
Triangular pelvic ligament
Sacrospinous ligament
Prevent lower end of sacrum and coccyx from being rotated at the SI joint
Sacrospinous and sacrotuberous ligaments
Pelvic diaphragm is formed by (2)
1) Levator ani muscles
2) Coccygeus
Pelvic diaphragm is incomplete at what portion
Anterior
Anterior defect in the pelvic diaphragm transmits (2)
1) Urethra
2) Vagina in females
Widest diameter of the pelvic inlet
Transverse
Visceral pelvic fascia around the cervix is called
Parametrium
Nerve supply: Coccygeus
S4-5
Lumbar sympathetic trunk and pelvic sympathetic trunk come together where
In front of coccyx
Constitute the PSY part of ANS in the pelvis
Pelvic splanchnic nerves
Pelvic splanchnic nerves: Arise from
S2,3,4
Pelvic splanchnic nerves: Preganglionic fibers synapse in ganglia of
Hypogastric plexus
Musculofascial structure that fills the gap of the pubic arch
Urogenital diaphragm
Urogenital diaphragm: Formed by
1) Sphincter urethrae
2) Deep transverse perineal muscles
Urogenital diaphragm: Fascial layers
1) Superior fascial layer
2) Inferior fascial layer
Urogenital diaphragm: Inferior fascial layer is aka
Perineal membrane
Small mass of fibrous tissue attached to the center of the posterior margin of the urogenital diaphragm
Perineal body