Female reproductive anatomy, pelvis and peritoneum Flashcards
What two halves does the pelvic inlet (brim) divide the pelvis into?
- False (greater) pelvis
2. True (lesser) pelvis - pelvic cavity
What two regions can the perineum be divided into? What are its boundaries?
Urogenital triangle and Anal triangle
Pubic symphysis, Ischial tuberosities, coccyx
Complete the sentence:
When standing upright, the plane of the pelvic inlet lies at … to the …
When standing upright, the plane of the pelvic inlet lies at 60 degrees to the horizontal
What are the differences in pelvic girdle shapes between males and females?
Males (android): Narrower, thicker boned, wedge-shaped, acute pubic arch
Females (gynaecoid): Wider, thinner bones, cylindrical cavity, broad pubic arch
What muscles makes up the pelvic floor?
Levator ani group (iliococcygeus, pubococcygeus and puborectalis)
Coccygeus
What are the functions of the pelvic floor muscles?
Supporting and pulling pelvic organs UP and FORWARDS
Preventing prolapse
Puborectalis - mainting anorectal angle and helps keep you continent
What is the urogenital hiatus covered by?
Perineal membrane (urogenital diaphragm) - tough fibrous sheet - has openings for urethra and vagina - space above it DPP and below it SPP
What are the functions of the perineal body?
Strong union between pelvic floor muscles and perineal membrane
Pelvic floor integrity
Supports posterior vaginal wall in females
Attachment point for anal sphincters
What are the boundaries of the DPP and what does it contain? mention innervation
Pelvic floor and perineal membrane
Contains voluntary (skeletal) muscles - innervated by the Pudendal nerve (S2-4)
Males: Bulbourethral glands/Cowper’s glands
What do the bulbourethral glands/cowper’s glands do and what happens if they become infected?
Secrete lubricating mucus
Can become infected/develop stones
Intense pain exacerbated by defecation/rectal exam
What are the boundaries of the SPP and what does it contain?
Between perineal membrane and fascia bound surrounding genitalia
Bulb of vestibule + Paired corpora cavernosa = crura of clitoris
Bulbosponiosis + ishiocavernosus muscles = cover erectile bodies
Greater vestibular glands/Bartholin’s glands
What are the vulva?
Folds of tissue guarding the urethral opening, vagina and clitoris
Describe the function of the greater vestibular (bartholin’s) glands and what happens if they are infected?
Drain into the vestibule at 5 and 7 o’clock position relative to vaginal opening
Can become inflamed, infected and form cysts or abscesses
What positions are episiotomies usually carried out?
Mediolateral position
Where can you find the ischioanal (ischiorectal) fossae?
In the Anal triangle (posterior)
Contains fat
Anterior extensions into the urogenital triangle
In the female, the peritoneum drapes over the pelvic organs, what two pouches does it form? Which pouch is more likely to get an infection?
- Vesicouterine pouch
- Rectouterine pouch/ Pouch of Douglas
Rectouterine is the most GRAVITY dependent - intraperitoneal fluid/blood/pus will accumulate - infection
Describe the vagina, mention its innervation.
Distensible fibromuscular tube - between bladder and rectum
Connects vestibule (space between labia minora) to the external os of the uterine cervix
Runs posterosuperiorly
Prox vag - pelvic splanchnic n - parasymp - S2-4
Dist vag - pudendal n - somatic - S2-4
What is the name of a prolapsed bladder and rectum through the vagina?
Cystocele
Rectocele
What can you use the posterior fornix of the uterus for?
Posterior fornix is DEEPEST, lying adjacent to rectouterine pouch - can pass a needle through the posterior fornix to access this
What are the thick smooth muscle layer and outer serosal layer of the uterus called?
Thick smooth muscle layer - myometrium
Outer serosal layer - perimetrium
What is the bimanual palpation procedure used for?
Check approx size and position of the uterus:
2 digits in vagina, one hand on abdo - check if uterus is anterverted and anteflexed
Describe the normal position of the uterus (mention angles).
Anterversion, Anteflexed
Angle of version = Vagina and Cervix
Angle of flexion = Cervix and Uterus
What can be the associated pathology with a retroverted and/or retroflexed uterus?
Subfertility problems
Endometriosis
What is the function of the fimbriae?
From the infundibulum lie over the ovary, ready to receive/collect the ovum at ovulation
Where does fertilisation usually occue?
Ampulla of the uterine tubes
What method can you use to view the shape and patency of the uterine cavity and tubes?
Hysterosalpingogram - inject dye into vagina - travels up uterus, through uterine tubes and into peritoneal cavity
Where do the paired uterine (fallopian) tubes open into?
Open into the peritoneal cavity
What might happen if there is an undetected ectopic pregnancy?
Rupture and cause haemoperitoneum
How might pelvic inflammatory disease (PID) be a risk for ectopic pregnancies and subfertility?
Uterine tubes may present a route of spread for infections from the vagina - PID
Salpingitis to tubal or tuboovarian abscesses
Embryologically, where and from what do the ovaries develop from?
Intermediate mesoderm
Posterior abdominal wall (L2 vertebral level)
Descend to lateral pelvic wall and drag blood supply and lymphatics with them to final position
Which ligament of the ovary contains the blood supply and lymphatics?
Suspensory ligament of the ovary
Why can you get medial thigh pain with ovarian pathology?
The ovaries are close to the obturator nerve - supplies the medial thigh. Can become impinged with ovarian pathology
Where do ovaries drain lymph to?
Para-aortic nodes
What do the ovarian and round ligaments connect? What are they a remnant of?
Both are remnant of the gubernaculum
Ovarian lig - connects ovary to uterus
Round lig - connect uterus to labia majora (runs via inguinal canal)
What might be a route of metastatic spread from the uterus to the inguinal lymph nodes?
Round ligament of the uterus
What three regions is the broad ligament separated into?
- Mesosalpinx (uterine tube)
- Mesovarium (ovaries)
- Mesometrium (endometrium)
What is the point where pelvic fascia come together?
Tendinous arch
What are the three parametrial ligaments that support the uterus?
- Uterosacral
- Cardinal ligament
- Pubocervical
What is the name of the fascia which surrounds the vagina and connects it to the tendinous arch?
Paracolpium
What is the golden rule for blood supply to the pelvic organs and perineum?
From branches of the internal iliac artery
Internal pudendal artery supplies perineum
Rich anastomoses between all organs - inc flow/demand during pregnancy
What passes below the uterine artery? Hint: Water flow under the bridge
Ureter passes below uterine artery (lateral to cervix)
What is at damage during a hysterectomy?
Ureter
Where do the following structures drain to?
Ovary, fallopian tubes, fundus of uterus, body of uterus, cervix, prox vagina, distal vagina, external genitalia
Ovary, fallopian tubes, fundus of uterus - paraortic nodes
Body of uterus, cervix, prox vagina - internal and external iliac nodes
distal vagina, external genitalia - superficial and deep inguinal nodes
P.S. round lig of uterus drains part of uterus to superficial inguinal nodes
What is the pelvic pain line?
The lowest point of peritoneal reflection over the pelvic organs. Determines the route visceral pain fibres takes from pelvic structures back into the CNS
Describe the innervation in the pelvic cavity below and above pelvic pain lines…
Above - pelvic organs covered in peritoneum, visceral sensory nerves travel alongside sympathetic nerves (refer pain T11-L2)
Below - not covered, visceral sensory n. - alongside parasymp nerves (refer pain S2-4)
External genitalia/distal vagina, perineal pouch muscles, sphincters - somatic innervation - pudendal nerve (S2-4)
How does the pudendal nerve pass in/out of the pelvic cavity?
Via the greater sciatic foramen and back in towards the perineum via lesser sciatic foramen.
Runs close to the ischial spine and sacrospinous ligament
How do you access the pudendal nerve when doing a nerve block?
Runs close to ischial spine, palpate through vagina - estimate location - anaesthesia for perineum, distal vagina and anal canal
