5. Pelvic Floor Flashcards
What is the pelvic floor formed by
Pelvic diaphragm:
Coccygeus & legato ani muscles
Superficial muscles & structures:
Anterior (urogenital) perineum
Posterior (anal) perineum
Describe the anterior (urogenital) perineum:
Shape/structure
What is below perianal membrane
Urogenital diaphragm fills gap in public arch
A ‘triangular sandwich’ with striated musc fibres btw 2 layers of fascia:
Superior fascia
Sphincter urethrae
Inferior/superficial fascia (thickened) - perianal membrane
Below perianal membrane:
Males - superficial transverse perianal membrane, bulbospongisus muscle, Ischiocavernosus muscle
Both sexes - superficial perianal pouch (urine can collect here if urethra ruptured)
What is the posterior (anal) perineum comprised of
Anus
Lavator ani
Ischiorectal fossae (pudendal nerve passes along lateral wall)
What are the major muscles involved in the pelvic floor
Lavator ani muscles:
Puborectalis
Pubococcgeus
Iliococcygeus
Coccygeus
Describe the function of the levator ani muscles
Bowl shaped & functionally work together
Paired muscles
Form 3 slings of muscle (anterior, intermediate, posterior)
3 slings extend from:
Posterior aspect of public bone
Fascia over obturator internus
Ischial spines
Describe the blood supply to the pelvic floor
Branches of the posterior trunk of the internal iliac artery:
Pudendal artery
Vaginal artery
Inferior rectal artery
Describe the innervation of the pelvic floor
Pudendal nerve (S2,3,4)
What is the perineal body
Pyramidal fibromusclular mass in centre of perineum
@ junction btw urogenital & anal triangles (ant & post perineum)
Males: btw bulb of penis & anus
Females: btw vagina & anus
What is the function of the perineal body
Essential for pelvic floor integrity (esp in females)
Anchors perianal muscles & rectum
Point of attachment for: Anal sphincters Bulbospongiosus Superficial transverse perianal muscles Fibres of levator ani
Central fulcrum for pelvic support
Describe the main types of pelvic floor dysfunction
Damage to pelvic floor & stretching of local structures:
Stretch of pudendal nerve (neuropraxia & musc weakness)
Damage to perianal muscles (musc weakness) (incl from episiotomy)
Stretch/rupture of ligament supporting Muscs (ineffective musc action)
Prolapse of organs
Stress incontinence
What are the causes/risk factors for pelvic floor dysfunction
Childbirth Intrinsic connective tissue laxity Chronic cough Obesity Menopause (atrophy of tissues after oestrogen withdrawal) Age
What are the treatments for pelvic floor dysfunction
Pelvic floor muscle exercises: easy, safe, effective
Continuance surgeries: increase support to sphincter mechanism
Prolapse procedures: maintain function
4 functions of the pelvic floor
Supports pelvic viscera:
Sphincter action - rectum & vagina
Resist increases in intra-abdominal pressure
Contributes to continence:
Sphincter - bladder neck
Contributes to childbirth
Contributes to truncal stability
Which muscles comprise the levator ani muscle group
Pubococcgeus
Iliococcygeus
Which muscles comprise the deep perineal muscle group
External urethral sphincter
Deep transverse perineal muscle
Which muscles comprise the superficial perineal muscle group
Ischiocavernosus
Bulbospongisus
Superficial transverse perineal muscle
Pubococcgeus:
What is its origin
What is its insertion
What is its function
Body of public bone
Anterior aspect of tendinous arch
Coccyx
Anococcygeal ligament
Elevate anus
Support pelvic viscera (prostate/vagina)
Iliococcygeus:
What is its origin
What is its insertion
What is its function
Ischial spines
Posterior aspect of tendinous arch
Coccyx
Anococcygeal ligament
Elevate anus
Support pelvic viscera
(Ischio)coccygeus:
What is its origin
What is its insertion
What is its function
Ischial spine
Coccyx
Elevates & supports pelvic floor
External urethral sphincter:
What is its origin
What is its insertion
What is its function
Pubic Ramus
Median raphe
Constricts urethra
Deep transverse perineal muscle:
What is its origin
What is its insertion
What is its function
Ischial Ramus
Median raphe
Supports pelvic floor
Ischiocavernosus:
What is its origin
What is its insertion
What is its function
Ischial Ramus
Corpus cavernosum
Compresses base of penis/clitoris
Bulbospongiosus:
What is its origin
What is its insertion
What is its function
Male: Central tendon of perineum & median raphe of penis
Female: Central tendon of perineum
Male: dorsal surface & bulb of penis
Female: base of clitoris
Male: constricts urethra, erects penis
Female: erects clitoris
Superficial transverse perineal muscle:
What is its origin
What is its insertion
What is its function
Ischial Ramus
Central perineum
Fixes Central tendon
External Amal sphincter:
What is its origin
What is its insertion
What is its function
Coccyx
Central tendon of perineum
Keeps orifice of anal canal closed
