pelvis, pelvic diaphragm, and urinary bladder COPY Flashcards
Describe on the hip the ilium, ischium, and pubis regions
* note they all meet in the acetabulum
What are the five parts that make up the pelvic inlet?
sacral promontary
Ala
Arcuate line
Pectineal Line
Pubic crest
What are the four regions of the pelvic outlet?
ischiopubic ramus
ischial tuberosity
sacrotuberous ligament
coccyx
Describe the ‘False pelvis’
superior to pelvic brim/inlet
considered part of the abdominal cavity
What is the floor of the true pelvis called?
pelvic diaphragm
What is the ‘subfloor’ of the true pelvis?
The perineum - inferior to the pelvic diaphragm
Describe the sacro-iliac joint
between the ilium and the sacrum - it is a synovial joint that may potentially ossify. it is strengthened by the sacroiliac ligaments both anteriorly and posteriorly
describe the pubic symphysis joint
it is a secondary carilaginous joint that only moves during childbirth
How do you distinguish the male pelvis from the female pelvis?
female pelvis = circular pelvic inlet, wider pubic arch (roman) 80-85 degrees, straight ischial spines, and alas flare outwards
male pelvis = heart shaped, gothic pubic arch (50-60 degrees) medially projected ischial spines
What purpose do the sacrospious and sacrotuberous ligaments have for the sacrum?
They prevent the upward tilting of the sacrum
Name the muscles of the pelvic diaphragm
IschioCoccygeus (AKA coccygeus)
iliococcygeus
pubococcygeus (splits into puborectalis and pubovaginalis or puboprostaticus)
*together the pubococcygeus and the iliococcygeus make up the levator ani muscle*
what nerve supplies the pelvic diaphragm?
The pudendal nerve
Which part of the pelvic diaphragm maintains the 90 degree angle of the anal canal?
the puborectalis muscle
Where does the perineal body sit in the female?
infront of the anus- behind the vaginal opening
Describe the branches of the internal iliac artery
internal iliac
Anterior division
- 3x parietal = obturator, inferior gluteal, internal pudendal
- 3x visceral = superior vesical, inferior vesical (vaginal vessel), middle rectal, and uterine artery (only in women)
Posterior division
- 3x parietal= iliolumbar, lateral sacral, superior gluteal
What artery runs with the pudental nerve through the alcock’s canal?
The internal pudendal artery. This is the site of the pudendal nerve block
Where can we palpate the pudendal nerve?
ischial spine
Does the uterine artery cross the ureter superiorly or inferiorly?
superiorly (water under the bridge)
What structure is commonly damaged in women who undergo historectomies?
The ureters are commonly mistaken for the uterine artery- uterine artery crosses the ureter superiorly - you can observe the difference in these structures b/c the ureter has peristaltic waves of contractions
What are the roots of the sacral plexus?
L4,5 S2,3,4
What are the 12 branches of the sacral plexus?
- superior gluteal
- inferior gluteal
- posterior cutaneous femoral
- piriformis
- obturator internus
- quadratus femoris
- sciatic (L4,5 S1,2,3)
- divides into tibial nerve and common fibular nerve
- medial plantar nerve
- lateral plantar nerve
- pudendal (S 2,3,4)
- coccygeal
describe the 3 sides of the bladder
Apex = median umbilical ligament to the umbilicus -which is a remnant of the urachus - part of how the bladder forms
superior surface - is covered with peritoneum and triangular in shape
inferolateral surfaces = retropubic fat pad and fascia
levator ani and obturator internus
base = trigone
Where does the bladder sit when it is distended vs. when it is empty?
When the bladder is empty it sits in the true pelvis
when it is full it sits in the false pelvis
can hold 150-600 ml urine
what muscle makes up the bladder?
The detrusor muscle - 2 longitudinal layers and a circular layer in the middle
What sort of surface is the bladder made up of?
transitional epithelium = tight junction with no leaks, but distensible
What is the trigone?
triangular area that culminates into urethral opening - functions as a urine funnel
Describe the ureteric orifices
This is where the ureters enter the bladder - they are oblique slit like openings to prevent reflux - found at lateral margins of the interureteric crest -
Describe the neck of the bladder
most inferior part of the bladder and the origen of the urethra
it is fixed by tough ligaments
female= pubovesical
male = puboprostatic
laxity of what ligament contributes to stress incontinence?
laxity of the pubovesical ligament in women
Describe the four parts of the male urethra
prostatic urethra (3cm)
membranous urethra (1cm)
bulbous urethra
penile/spogy urethra
Approx what length is the female urethra?
4cm - very short, and susceptible to infections
describe the blood supply to the bladder
superior/inferior vesical (vaginal in women)
obturator/inferior gluteal branches
+uterine branches in women
Venous drainge is by vesical venous plexus or prostatic/vaginal venous plexus into the internal iliac vein
What venous system allows prostate cancer to spread fairly easily?
The valveless veins of bateson -
Describe the innervation to the bladder
parasympathetic
- pelvic splanchnic nerves - inhibit internal sphincter and provide motor function to the detrusor
sympathetic
- provide motor to internal sphincter- pain on over distention *clinically this is why we use anticholinergics for symptoms of the detrusor overactivity *
Where does the external sphincter sit in the pelvis?
in women- external sphincter is within the deep perineal pouch
in men - external urethral sphincter is also within the deep peroneal pouch!
