Pelvic walls and floor Flashcards
What are the 2 main parts of levator ani?
Pubococcygeus - more medially
Iliococcygeus - more laterally
Describe the parietal pelvic fascia of the pelvis
Covers the internal wall of the pelvis. Thickens over the obturator internus to form the tendinous arch of the pelvis and levator ani
Anteriorly it forms the puboprostatic ligament and the pubovesical ligament
Describe the endopelvic fascia
Acts as a packing material around the organs and there are 2 types - loose and condensed
Loose fills spaces in the pelvic e.g. the retropubic (pre-vesical) space
Condensed are thickenings of the fascia e.g. the hypogastric sheaths running along the posterolateral walls of the pelvis
Describe the attachments of iliacus muscle
Originates at the iliac fossa
Joins with the psoas muscle to create iliopsoas
Inserts into the lesser trochanter of the femur
What is the perineal body?
A small piece of fibrous tissue that lies in the pelvic floor at the edge of the urogenital diaphragm between the openings of the vagina (female), urethra (male) and the anal canal
Describe the visceral pelvic fascia
Covers the pelvic organs. The parietal and visceral fascia blend as the organs pierce the pelvic floor.
Lateral extension of the visceral fascia from the vagina to the tendinous arch forms the paracolpium
Describe the sacrum and its articulations
Formed of 5 fused sacral vertebrae
Articulates with the L5 vertebrae and the coccyx
What muscles attach to the perineal body?
Puboprostaticus
Pubovaginalis
External anal sphincter
Perineal muscles
What is this muscle and its functions?
Psoas
Hip flexion and bends trunk laterally (one)
Raise trunk from a supine position (both)
What muscle is highlighted?
Coccygeus
Describe the path taken by the fibres of pubococcygeus?
The fibres pass from the pubic bones to wrap around the prostate/vagina and the rectum
The fibres that wrap around the vagina and prostate insert into the perineal body and are named puboprostaticus and pubovaginalis
In both sexes the more posterior fibres continue to wrap around the rectum - puborectalis
What are the attachments of piriformis?
Originates on anterior/pelvic surface of the sacrum
Passes through greater sciatic foramen to cross the gluteal region
Inserts into greater trochanter of femur
What are some of the features that increase the internal diameter of the female pelvis?
Pubic angle at the pubic symphysis is wider
Ischial spines don’t protrude into the pelvic cavity as markedly
Sacrum is flatter than what is seen in a male
What is the innervation of the iliacus muscle?
Femoral nerve
What is the innervation of the psoas muscle?
Lumbar plexus - direct branches of L2-4 anterior rami
What joint classifications are the lumbosacral and pubic symphysis joints of the pelvis?
Secondary cartilagenous - allows for the cushioning of stresses passing into the pelvis from the trunk and passing around the pelvic bowl
What is the role of the cocygeus muscle?
Supports the pelvic viscera and flexion of the coccyx
What muscle is highlighted?
The puborectalis of the pubococcygeus
What is the classic shape of the female pelvis?
Gynecoid