Practical 1 - Station 2: Muscles and Walls of the Pelvic Cavity Flashcards
What are the boundaries of the pelvic cavity?
Antero-inferior wall
Two lateral walls
Posterior wall
What forms the anterior inferior wall of the pelvic cavity?
The bodies and rami of the pubic bones and pubic symphysis
What muscle forms the lateral walls of the pelvic cavity?
Obturator internus
What is the action of the obturator internus?
Lateral rotation of the hip
What foramen does the obturator internus exit the pelvic cavity?
Lesser sciatic foramen
What muscle is present in the posterior wall of the pelvis?
Piriformis
What is the action of piriformis?
Lateral rotation of the hip
Which foramen does piriformis exit the pelvic cavity through?
Greater sciatic foramen
What nerve network lies on top of piriformis?
Sacral plexus
What are the 3 muscles that make up the pelvic floor?
Puborectalis
Pubococcygeus
Iliococcygeus
Identify
Puborectalis
Identify
Pubococcygeus
What is the third muscle of the levator ani?
Iliococcygeus
What is the perineal body?
Where multiple muscles of the perineum meet
What muscles join up at the perineal body?
Anterior levator ani
Bulbospongiosus
External anal sphincter
Superficial transverse perineal muscle
What is the anococcygeal body?
Median raphe where the levator ani, external anal sphincter and fibrous connective tissue meet
What are the two main functions of the pelvic diaphragm?
Maintain continence
Weight bare above structures
What is the innervation of the pelvic diaphragm?
S2, S3, S4 or nerve to levator ani
What is the nerve supply to this muscle?
Coccygeus muscle
S4, S5
What is a cystocele?
Weakening of fascia between the vaginal canal and the bladder meaning the bladder can prolapse into the vagina
What is a rectocele?
Bulging of the front wall of the rectum through a weakness leading to the rectum prolapsing into the vaginal canal
Why is injury to the pelvic floor during childbirth potentially damaging?
Damage to the perineal body can lead to incontinence
What surgical technique can be used to reduce damage to the perineal body?
Episiotomy
What type of episiotomy shown here is the most common and why is an episiotomy good even though you’re still cutting?
Mediolateral episiotomy
- Cutting heals better than tearing
- The perineal body is not damaged
