The Pelvic Floor Flashcards
What does the pelvic floor form the upper border of?
The perineum
What pierces the pelvic floor?
Urethra Vagina Rectum
Functions of the pelvic floor?
Support the abdominopelvic viscera through tonic contraction Resistance to increase in intra-pelvic/abdominal pressure during coughing, lifting heavy objects Urinary and fecal continence
What two parts does the pelvic floor separate?
The perineum and the abdominal cavity
What shape is the pelvic diaphragm?
Bowl or funnel shaped
What are the two significant holes in the pelvic floor?
Urogenital hiatus - anteriorly situated allowing passage of urethra and vagina in females Rectal hiatus - centrally positioned gap allows passage of anal canal
What is between the two holes in the pelvic floor?
The perineal body - a fibrous node that joins the pelvic floor to the perineum
How is urinary and fecal continence maintained by the pelvic floor?
Muscle fibres have a sphincter action on the rectum and urethra Can relax to allow urination and defacation
What are the main muscles that make up the pelvic floor?
Levator ani -pubococcygeus -puborectalis -iliococcygeus Coccygeus
Innervation of the levator ani muscles?
Branches of the pudendal nerve S2-4
Attachments of the levator ani muscles?
Anteriorly - pubic bodies of hip bone Laterally - thickened fascia of obturator internus called the tendinous arch Posteriorly - ischial spines of hip bone
What is the pelvic floor?
A muscular and fibrous tissue diaphragm which fills the lower part of the pelvic canal Closes the abdominal cavity
Describe the positioning of the puborectalis
U-shaped sling, extending from the pubic bone, past the urogenital hiatus, around the anal canal.
What does tonic contraction of the puborectalis create?
Bends the canal anteriorl, creating the anorectal angle (90*) at the anorectal junction.
Main function of the puborectalis?
Faecal continence
Which muscle makes up the main constituent of the levator ani?
Pubococcygeus
Describe the positioning of the pubococcygeus
Arise from the body of the pubic bone and anterior aspect of the tendinous arch
Fibres travel around the margin of the urogenital hiatus and run posteriomedially, attaching at the coccyx and anococcygeal ligament
Loop around the vagina (pubovaginalis) and prostate as they run inferiorly and medially
Some fibres terminate in the perineal body
Describe the position of the iliococcygeus
Thin muscle fibres, start anterioly at the ischial spines and posterior aspect of the tendinous arch.
Attach posteriorly to the coccyx and anococcygeal ligament
Innervation of the coccygeus?
Anterior rami of S4 and S5
Describe the position of the coccygeus muscle.
Smallest and most posterior
Originates from ischial spines and travels to lateral aspect of the sacrum and coccyx, along supraspinous ligament
What is the role of the levator ani muscle during birth?
Supports fetal head during cervix dilation in birth
What is at high risk of damage during the second phase of birth?
Levator ani and pudendal nerve
Especially pubococcygeus and puborectalis as they are situated most medially
What can injury to the pelvic floor muscles lead to?
Urinary stress incontinence
Rectal incontinence
Prolapse of pelvic viscera
What can cause prolapse of the vagina?
Trauma or decrease in tone to muscles
Damage to the perineal body in childbirth
How can damage to the perineal body be avoided in childbirth?
How?
Episiotomy - surgical cut to the peritoneum
Prevents uncontrolled tearing of perineal muscles
Risks of an episiotomy?
Can cause damage to the vaginal mucosa and submucosa
What leads to rectal herniation?
When medial fibres of the puborectalis are torn within the perineal body
Risk factors for prolapse?
Age
Multiple vaginal deliveries
Family history
Weight
Chronic coughing
How can the pelvic floor be repaired?
Surgically
How can the pelvic floor damaged in child birth?
Stretch of the pudendal nerve causing neuropraxia and muscle weakness
Stretch and damage of pelvic floor and perineal muscles
Stretch and rupture of ligaments that support the muscles - ineffective muscle action
Risk factors of pelvic floor dysfunction?
Age
Menopause - atrophy of tissues after oestrogen withdrawal
Obesity
Chronic cough
Intrinsic connective tissue laxity due to intrinsic conditions
What do continence surgeries do?
Increase support to sphincter mechanism and prevent descent of bladder neck
What can be used in continence surgeries?
Vaginal tape
Colpsuspension
Side effects of continence surgery?
Voiding difficulty/urinary retention
Overactive bladder disease (obstruction)
What is done in prolapse procedures?
Replace prolapsed organs
Restore connective tissue supports
Maintain function
Problems with prolapse procedures?
Recurrence
New incontinence
Dyspareunia
Which muscles can be felt on contracting the rectum?
External anal sphincter
Puborectalis
How can childbirth lead to incontinence?
The pubococcygeus can be torn - Can lead to herniation of the bladder or prolapse with subsequent incontinence
The puborectalis can be torn with the perineal body leading to herniation of the rectum - faecal incontinence or difficulty in defacation.
What is the aim of an episiotomy?
Avoid damage to the perineal body
What tissues need to be repaired after an episiotomy?
Vaginal mucosa and submucosa, perineal skin, muscles and fascia of the perineum
