8a - Intro/anatomy Flashcards
WHAT ARE PELVIC ORGANS??
Organs that sits within the Pelvic Cavity
Anterior compartment pelvic floor
Bladder
Urethra
Central/apical compartment pelvic floor
Uterus
VAgina
Posterior compartment
Rectum
Anal Canal
Components of pelvic floor
Muscular
Fasicial
Muscular components of the PF
Deep pelvic floor layer:
- Levator Ani
- Coccygeus
Superficial Pelvic Floor Layer
- Urogenital Triangle
- External Anal Sphincter
Parts of Levator Ani
- Puborectalis
- Pubococcygeus
- Iliococcygeus
What does the deep pelvic floor do?
- FORWARD PULL OF STRUCTURES
Compresses Lumens
Maintains Anorectal Angle - “angle between rectum and anal canal” - LIFT OF PELVIC STRUCTURES ie ‘levator”
Lifts to support the pelvic organs, removing strain on the
endopelvic fascia
School of Physiotherapy
What
Function superficial PF muscles
Provides added closure to vagina and anus (rather than lift)
Muscles of superficial PF - Anterior Half
“Urogenital
Triangle”
Ischiocavernosus
Bulbocavernosus /
Bulbospongiosus
Transverse Pereneii Superficialis
Muscles of superficial PF - posterior half
External anal sphincter
What is the perineal body?
• Pyramidal fibro-muscular mass in the midline of the perineum between vagina and anus • Central insertion point for numerous structures (muscles and fascia) that make up the pelvic floor • Commonly torn during childbirth
Nerve supply deep pelvic floor
Levator Ani Nerve
Nerve supply superficial pelvic floor
Pudental nerve
Primary structures holding the pelvic organs in place
Endopelvic fascia
Sub-components of the EndoPelvic Fascia
Pubocervical Fascia
Rectovaginal Fascia
Uterosacral Ligaments
Pubocervical Fascia
Situated between the back of the bladder / urethra and the
front of the vagina
• Meant to holds the bladder and urethra in their normal
position away from anterior vaginal wall.
Disruption to what can cause an anterior vaginal wall prolapse
Pubocervical fascia
Rectovaginal Fascia
Meant to holds the rectum in it’s normal position away
from the posterior vaginal wall
Disruption to what can cause an posterior vaginal wall prolapse
Break in rectovaginal fascia
Uterosacral Ligaments
• Suspend lower aspect of uterus / cervix up and
attach to sacral base
• Maintains uterus high in apical section of vagina
Disruption to what can cause uterine prolapse?
Uterosacral ligaments
What is the Pelvic Floor?
The pelvic floor is a complex web of muscle, fascia and fibrous
tissue that helps support the pelvic organs.”
Pelvic floor dysfunction =
PELVIC FLOOR MUSCLE DYSFUNCTION OR PELVIC FLOOR FASCIAL DYSFUNCTION OR BOTH!!
How does the bladder work
– “The Tank” - Storage facility for urine
– Receives urine from kidneys via Ureters
– Muscular wall called the “Detrusor” – contracts to push urine out
Two phases of micturition
Storage phase (>99%) Voiding phase (< 1%)
What happens during bladder storage phase?
Storage Phase (>99%)
Whilst bladder is filling
• Relaxed Detrusor expansion
• Contracted Urethral Sphincters
What happens during bladder voiding phase?
Voiding Phase (<1%)
While bladder is emptying
• Contracting Detrusor
• Relaxed Urethral Sphincters
Storage and expulsion of urine. - intra-vesical pressure and urethral pressure
For Storage of Urine to Occur
IVP < UP
For Expulsion of Urine to Occur
IVP > UP
How IVP remains low despite increase in urine volume during storage phase?
Tightening of urethral sphincters
What muscle activity occurs for normal voiding?
Detrusor contracts and urethral sphincters relax.
IVP increases and UP decreases
IVP becomes > UP
Urine Released through Urethra
Function of stomach
- Minimal absorption
* Primarily break up of food
Function of small intestine
- 3 Sections: Duodenum, Jejunum, Ileum
- Primarily nutrient absorption
- At end of small intestine consistency of ‘thick pea soup’
Function of large intestine
• 4 Sections: ascending, transverse, descending, sigmoid
• Primarily re-absorption of H20
– 1500mls at start of colon reduced to150mls at end
• Stool consistency determined by time in colon
– The longer the transit time through the colon the harder the stool
• Transit time is usually 1-3 days
Function of rectum
RECTUM (similar function to bladder)
• Lowest part of GIT
• Just before anal canal
• Purpose:
– Storage of feces until appropriate time to empty
– ie equivalent role as bladder in urinary system
Function of anal canal
ANAL CANAL (similar fx to urethra)
• Starts at end of rectum, level with tip of coccyx,
• Ends at anal verge
• Purpose
– Release of faeces from the body at an appropriate
time
Muscles that maintain faecal continence
Puborectalis
External Anal sphincter
Internal Anal Sphincter
PUBORECTALIS action defecation
Pulls anorectal junction forward, maintaining anorectal angle and
acting as a ‘kink’.
EXTERNAL ANAL SPHINCTER action defecation
- Skeletal muscle
- Voluntary Control via pudendal nerve
- Responsible for 30% of anal closure pressure
Internal anal sphincter action defecation
Smooth muscle
Involuntary control via ANS
70% resting anal closure pressure
Normal Defecation Sequence
- Peristalsis triggered by food / fluid intake, exercise etc
- Stool is propelled into rectum
- Distension of rectal walls triggers relaxation of Internal Anal
Sphincter……. “Recto-anal Inhibitory Reflex” - Stool descends into upper anal canal
- PR and EAS increase activity until person reaches toilet
- At appropriate time, person relaxes PR and EAS
defecation occurs
