Pelvic Floor

Question 1

Pelvic Cavity Boundaries

Answer 1

Pubic symphysis and bones of pelvis bound cavity

Lateral walls are padded by obturator internus muscles

Sacrotuberous and sacrospinous ligaments form greater sciatic foramen in posterior wall, filled by piriformis

Question 2

Pelvic Cavity Contents

Answer 2

Terminal parts of ureters

Urinary bladder

Rectum

Pelvic genital organs

Blood vessels, lymphatics, nerves

Question 3

Pelvic Cavity Limitations

Answer 3

Limited inferiorly by pelvic diaphragm (suspended above but descends centrally to level of pelvic outlet, forming bowl-like pelvic floor)

Question 4

Pelvic Diaphragm

Answer 4

Consists of:

• Coccygeus and levator ani muscles
• Fascia covering superior and inferior aspects of muscles

Question 5

Levator Ani

Answer 5

Forms dynamic floor for supporting abdomenpelvic viscera

Tonically contracted most of the time to support viscera and assist in maintaining urinary and fecal continence

Actively contracts during forced expiration, coughing, sneezing, vomiting, and fixation of trunk when carrying trunk during heavy load

Must relax to allow urination and defecation

Question 6

Levator Ani (Muscle Group)

Answer 6

Compromised of 3 individual muscles that work to perform similar action: support pelvic organs

Act to prevent prolapse of GI and urogenital organs by maintaining muscle tone to 1) create pelvic support “sling” and 2) act as “secondary” sphincter muscles to help close orifices of rectum and vagina

Question 7

Coccygeus

Answer 7

Muscle that forms lateral wall of pelvic floor and also helps form part of pelvic sling to support pelvic contents

Question 8

Perineal Membrane

Answer 8

Fascial sheet of tissue that supports pelvic floor

Also serves as attachment site for muscles of perineum, which help sphincter muscles of genitourinary system maintain continence (prevent release of urine and prolapse of organs)

Insertion same as sacrospinous ligaments