Pelvic Viscera Flashcards
How do the bladder and uterus develop?
As 2 halves that come together in midline and fuse
What is the implication of the neurovascular supply for the bladder and uterus because of their development?
Neurovascular structures from each side wall; ie: paired
Where is the bladder?
Sits behind pubic bone
In adult, empty bladder sits low
As it fills, and in child, pushes up beyond pubic bone towards abdominal cavity, pushing peritoneal cavity above it
What is the retropubic space?
Small space between bladder and pubic bone
What is the shape of the bladder?
Pyramid tipped forwards
So apex points anteriorly, abutting pubic bone
Base of bladder directed posteriorly, sitting against rectum in male and genital tract in female
What is the triangular base of the bladder called?
Trigone
Describe the wall of the trigone
Smooth wall
Mucosa quite densely adherent to smooth muscular wall
What is the mucosa like in the bladder except for the trigone?
Thrown up into swirls and whorls over detrusssor muscle
In which direction is the apex of the trigone directed?
Downwards
Which structures enter or exit the trigone at each point?
Supralaterally: ureters enter
What is the course of the ureters?
From hilum of kidneys
Vertical descent over posterior abdominal wall on psoas, roughly aligning with tips of lumbar transverse processes
Tip over pelvic inlet
- Point of narrowing - external kinking rather than internal structure
Runs along side wall of pelvis
Crosses towards midline
Pierces muscular wall of bladder
Tunnels through wall at oblique angle, acting as functional sphincter
How does the functional sphincter of the ureters work in the wall of the bladder?
As bladder contracts, intramural portion of ureters pushed closed, therefore prevents retrograde flow of urine
Describe the neck of the bladder
Part of bladder surrounding where urethra exits bladder
Relatively stable
Describe the fundus of the bladder
Above neck
Expands
How do you stabilise the bladder?
Must stabilise fixed part
Neck of bladder stabilised
Ligaments going forward attach neck to pubic bone = pubovesical ligaments
What is associated with the posterior aspect of the bladder in the male?
Part of male reproductive tract
Where does the vas deferens originate?
At epididymis of testis in scrotum
What is the course of the vas deferens?
Part of spermatic cord Ascends and traverses inguinal canal Passes along side wall of pelvis Crosses side wall towards posterior aspect of bladder Approaches base of bladder posteriorly Joins ducts of seminal vesicles
What is the relationship between the vas deferens and the ureter?
Vas deferens crosses over ureter
Describe the ejaculatory duct
Paired/conjoined ducts form single duct
- Vas deferens carries sperm from testis
- Seminal vesicles secrete thick alkaline with fructose
What does the ejaculatory duct empty into?
Prostatic part of urethra
What does the common iliac artery divide into?
Internal iliac artery, which dips down into pelvis
External iliac artery, which is continuing along brim
What is the ureter crossed by in each sex on its course from the side wall to the bladder?
In males, crossed by vas deferens
In females, crossed by uterine artery
Describe the importance of the uterine artery as a surgical landmark
When surgeons performing hysterectomy, need t tie off uterine blood supply
When they put ligature around uterine artery, have to make sure they’ve clearly identified ureter, and make sure their ligature isn’t catching up ureter as well
Where is the prostate gland?
Situated between neck of bladder above, and levator ani and urogenital diaphragm below
What is the urethral crest?
Prostatic part of urethra has bulge in middle of it
What are the prostatic or urethral sinuses?
Urethral crest has grooves on either side of it
Ejaculatory duct opening onto crest in either side
Prostate gland opens into sinuses via ducts
What part of the prostate is palpable on a per rectum exam?
Posterior surface
Front of fingers directly related to posterior aspect of prostate gland
How does the consistency of the prostate gland change if it enlarges because of malignancy?
Hardens and loses normal lobulation
Which lobe of the prostate gland generally enlarged in benign prostatic hypertrophy?
Medial/middle lobe
Where is the middle lobe of the prostate gland?
Between ejaculatory duct and prostatic urethra
What does the middle lobe of the prostate gland impinge on as it enlarges?
Ejaculatory duct
Prostatic urethra
What are the middle midline structures in the female?
Uterus
Vagina
What is the size of the uterus?
Textbook size = 8 x 5 x 3 cm
Actual size variable
- Involutes post-menopause
- After carrying pregnancy to term, doesn’t decrease to size before
What is anteversion?
(Angulation on vagina)
Bent forward on vagina
What is anteflexion?
Uterus itself bent forward
What is the normal position of the uterus?
Anteverted and anteflexed
What are the variations in position of the uterus?
Less anteversion, no version, retroversion
What is retroversion of the uterus associated with?
Classically associated with back pain in pregnancy and often in periods
Can have implications on carrying pregnancy to term
How can you tell if the uterus is anteverted or retroverted?
On per vagina exam
What is the shape of the uterine cavity?
Roughly triangular
What does the uterus receive at each supralateral angle?
Uterine tube
What is the apex of the uterus continuous with?
Cervical canal
What demarcates the cervix?
Internal uterine opening = internal os
External uterine opening = external os
Where is the fundus of the uterus?
Convex part above entry point of uterine tubes
Where is the body of the uterus?
Below entry point of uterine tubes
Where is the isthmus of the uterus?
Body tapers into isthmus
Isthmus becomes continuous with cervix
In which direction is the uterus flattened?
A-P direction
How long is the cervix?
2-3 cm
Where do the external os and terminal portion of the cervix sit?
Sit down into superior part of vagina, such that vagina envelopes terminal portion of cervix
What is a fornix?
Space in vagina on either side of cervix
How do you directly related to the pouch of Douglas in a per vagina exam?
Stick fingers in posterior fornix
What happens to the fundus of the uterus during pregnancy?
Pushes up, pushing peritoneal cavity above it
What happens to the body and isthmus of the uterus during pregnancy?
Expand dramatically
Which part of the uterus is fixed?
Cervix
What are the ligaments that fix the cervix in place?
Lateral cervical ligaments
Uterosacral ligaments
Pubocervical ligaments
Which ligaments fixing the cervix are the strongest?
Lateral cervical ligaments
Where do the lateral cervical ligaments attach?
Side wall of pelvis
Where do the uterosacral ligaments attach?
Sacrum, posteriorly
Where do the pubocervical ligaments attach?
Pubis, anteriorly
Which ligaments fixing the cervix are the weakest?
Pubocervical ligaments
What are the lateral cervical ligaments made of?
Fascial condensations around neurovascular structures
What artery do the lateral cervical ligaments transmit?
Uterine artery from internal iliac artery to uterus
What does anything supporting the vagina also support?
Uterus, indirectly
What supports of the vagina support the uterus from below?
Levator ani
Fascial supports of vagina
Other than the ligaments, what else supports the cervix?
Perineal membrane
How can the ligaments of the pelvic viscera slacken and weaken?
Stretching of childbirth and/or effects of loss of oestrogen at menopause
What does weakening and slackening of the ligaments of the pelvic viscera do?
Prolapse of pelvic structures, especially uterus
Describe prolapse of the uterus
Uterus can drop down into vagina
Grades of uterine descent
External os and terminal part of cervix can even appear at level of labia
What happens when the fascial supports of the vagina become slack and weakened?
Bladder to fall back and encroach on front of vagina
Sometimes rectum can fall forwards and encroach on vagina from behind
How long are the uterine tubes?
10-14 cm
What are the different parts of the uterine tubes?
1st part, starting at uterus, = intramural
- Traverses muscular uterine wall to connect with uterine cavity
- Gets progressively wider as it heads for side wall of pelvis
Isthmus changes in diameter
Vast majority of uterine tube = ampulla
- Large and wide
Ends in series of finger-like projections = fimbria
- Related to ovary
- Catch ovum at time of ovulation
What is the relationship between the uterus and the peritoneum?
Uterus covered by peritoneum in front, top, and back
Extends to walls of pelvis as double fold on either side
At side walls, sweeps front and back forming peritoneal lining of pelvis
What is the double fold of peritoneum hanging off the uterus called?
Broad ligament
What does the broad ligament hang off?
Uterine tubes - they’re like curtain rods
What is the shape and size of the ovaries?
Almond sized
Almond shaped
Where do the ovaries sit?
On back of posterior leaf of broad ligament
Inside peritoneal cavity
Around which structure must the fimbria move to collect the ovum?
Go around back of broad ligament
What are the three structures that come off the supralateral angles of the uterus?
Uterine tubes head off laterally
Ovarian ligament posteriorly
Round ligament anteriorly
What is the ovarian ligament?
Proper ligament connecting ovaries to upper side of uterus
What is the round ligament?
Remnant of gubernaculum
Equivalent of spermatic cord in males
Traverses inguinal canal and connects to labia
Pulls ovaries onto side wall of pelvis during development
What is the vagina?
Long muscular tube
Longer posterior wall than anterior wall
Where does the rectum sit in the pelvis?
Posteriorly, back within concavity of sacrum
At what level is the rectosigmoid junction?
S3
What happens at the rectosigmoid junction?
Taenia coli once more become continuous longitudinal coat over rectum
What is the mucosal lining of the rectum like?
Make mucosal shelves
What is the dilated terminal portion of the rectum called?
Ampulla
Where is faeces stored until defecation?
In ampulla of rectum
What is the main artery of the pelvis?
Internal iliac artery
Since the internal iliac artery is the most variable artery in the body, how are the branches named?
By working back from structure they supply
What are the two sources of blood vessels for the midline structures of the pelvis?
Those coming from above
Those coming off internal iliac arteries from side walls
Where do the ovarian arteries come from?
From above: gonadal branches from side walls of abdominal aorta
Where does the superior rectal artery come from?
Above
What does the superior rectal artery supply?
Rectum
Which branch of the internal iliac supplies the visceral structures/?
Anterior branch
Which artery supplies the bladder?
Superior vesical artery
What does the inferior vesical artery supply?
In males, and sometimes in females, reinforces blood supply to bladder, because it also supplies components of reproductive tract on back of bladder
What is the blood supply to the vagina?
Uterine artery gives of vaginal branch that heads down
What is the course of the uterine artery?
Comes off side wall from internal iliac artery
Runs in lateral cervical ligament towards cervix
Gives vaginal branch
Turns up and runs along lateral side of uterus
Meets and anastomoses with ovarian artery where uterine tube connects with uterus
What is the blood supply to the uterine tube?
Ovarian artery, after it supplies ovary
In females, what is the inferior vesical artery a branch of?
Vaginal artery, rather than internal iliac artery
What reinforces the blood supply to the rectum?
Middle rectal artery, coming off internal iliac artery
Site of porto-systemic anastomoses
What is the nerve plexus of the pelvic viscera?
Hypogastric plexus
Where is the hypogastric plexus situated?
On either side of rectum
What fibres does the hypogastric plexus contain?
Sympathetic and parasympathetic
Where are the pelvic parasympathetic components from?
Sacral plexus, from S2-4
Where are the pelvic sympathetic components from?
Thoracolumbar chain
How do the parasympathetic and sympathetic components reach the pelvic viscera?
Sacral plexus and thoracolumbar chain feed into superior hypogastric plexus
Form hypogastric nerves on either side
Feed into inferior hypogastric plexus
To viscera
