Female reproductive anatomy Flashcards
What are the landmark features of the urogenital triangle?
Pubic symphysis + 2 ischial tuberosities
What are the landmark features of the anal triangle?
Coccyx + 2 ischial tuberosities
What muscles make up the pelvic floor?
Levator ani group (iliococcygeus, pubococcygeus, puborectalis) + Ischiococcygeus
What makes up the pelvic girdle?
Paired hip bones and sacrum - united by sacroiliac joints, pubic symphysis and strong ligaments
Where is the pelvis?
Space bound by pelvic girdle
Where is the pelvic inlet?
Divides the pelvis into 2 main regions (false or greater pelvis and true or lesser pelvis)
What is the false (greater) pelvis?
Lies above pelvic inlet (abdominal region of pelvic girdle)
What is the true (lesser) pelvis?
Lies below pelvic inlet - provides framework for birth canal in females
What are the 2 regions of the perineum?
Urogenital and anal triangles
How is the pelvis normally orientated?
60 degrees to the horizontal (so tilts anteriosuperiorly) meaning that the ASIS and pubic tubercles are in line with each other
Urogenital and anal triangles are also angled relative to each other (urogenital faces inferiorly, anal triangle faces posteroinferiorly)
Why are pelvic measurements not clinically useful?
Have limited clinical value in predicting ease of childbirth
What type of joint unites the pubic bones anteriorly?
Secondary cartilaginous (hyaline cartilage) - pubic symphysis
What is the route of weight transmission through the pelvis when sitting and what is the name of the condition that can be caused by too much sitting?
Weight transmission is through the ischial tuberosities
Too much sitting can cause ischial bursitis
What features distinguish a pelvis as being female?
Wider pubic arch
Shorter (and less inward pointing) ischial spines
Cylindrical pelvic cavity (wide pelvic inlet and outlets)
Relatively thinner bone
What are the terms used to define a male and female pelvis?
Male = android Female = gynaecoid
What are the attachments of the sacrotuberous ligaments?
Sacral spine to ischial tuberosities
What are the attachments of the sacrospinous ligaments?
Sacral spine to ischial spine
What structures pass through the greater sciatic foramen?
Piriformis muscle
Superior and inferior gluteal nerves and vessels
Nerves of the sacral plexus
What structures pass through the lesser sciatic foramen?
Pudendal nerve
Internal pudendal vessels
Obturator Internus
Nerve to the obturator internus
What is the main route of venous drainage from the pelvic organs?
Venous drainage into internal iliac veins and then IVC
What is the clinical relevance of the venous drainage of the pelvic organs?
Can drain into the vertebral plexus allowing for metastatic cancer spread up spine (as the valves are veinless)
What are the anatomical of the ureters and its clinical relevance?
Ureters pass deep to uterine arteries and laterally to cervix - risk of damage during hysterectomy
What is the lymph drainage of the uterus?
Fundus, ovaries and uterine tubes drain to para-aortic nodes
Body of uterus drains to internal and external iliac lymph nodes
What is the sensory nerve supply to the uterus?
T10-L1/2
At what vertebral level would you insert an epidural?
L3/4
At what vertebral level would you insert a spinal nerve block?
L3/4 to L5/S1 into subarachnoid space
Where would you insert a caudal anaesthesia and what landmarks are used to find this?
Sacral Hiatus - inferior apex of an equilateral triangle measured between the two PSIS
What does a pudendal nerve block anaesthetise?
Perineum
Distal vagina
Anal canal
What is the function of the parametrial ligaments?
Support the uterus
What ligaments provide support for the uterus?
Broad ligament
Parametrial ligaments: pubocervical, transverse cervical and sacrocervical
What are the attachments of the parametrial ligaments?
Pubocervical = cervix to posterior surface of pubic symphysis
Transverse cervical = lateral cervix and lateral fornix of vagina to lateral pelvic wall
Sacrocervical = cervix to sacrum
What sits anatomically between the uterus and the rectum and why is it clinically relevant?
Rectouterine pouch - most gravity dependent region so place where fluid/ blood/ pus will accumulate
What is the nerve supply to the vagina?
Proximal = parasympathetic S2-4 (pelvic splanchnic) Distal = somatic S2-4 (pudendal)
What is the lymph drainage of the vagina and external genitalia?
Proximal vagina = internal and external iliac nodes
Distal vagina and external genitalia = superficial and deep inguinal nodes
What is the normal anatomical arrangement of the uterus, cervix and vagina?
Anteflexed and anteverted
What is the name of the procedure that can be used to test patency of the uterine tubes?
Hysterosalpingogram
Where is the perineum?
Diamond shaped region below the pelvic floor between thighs - can be divided into urogenital and anal triangles
Which measurements of the pelvis are the narrowest and widest points?
Widest = transverse diameter Narrowest = interspinous distance
What muscles make up the pelvic floor?
Levator Ani group = Iliococcygeus, pubococcygeus and puborectalis
+ Ischiococcygeus
Which nerve innervates the pelvic floor muscles?
S4 (+ some pudendal)
Which muscle of the pelvic floor helps to maintain faecal continence and how?
Puborectalis - maintains anorectal angle to prevent incontinence
What are the functions of the pelvic floor muscles?
Support pelvic organs
Prevent prolapse
Maintain continence
What is the perineal body and what is its function?
Tough mass of fibre between external genitalia and anal canal - provides point of union between pelvic floor muscles and perineal membrane
Important for pelvic floor integrity, supports posterior vaginal wall and attachment point for anal sphincters
What is the contents of the perineum in females?
Crura of clitoris Bulb of vestibule Labia (majora and minora) Greater vestibular glands Internal pudendal vessels and branches Pudendal nerve and branches Perineal membrane
What is the contents of the perineum in males?
Crura and bulb of penis Urethra Scrotum and testes Bulbourethral glands Internal pudendal vessels and branches Pudendal nerve and branches Perineal membrane
Where do the greater vestibular glands drain?
Into vestibule (at 5 and 7 o’clock positions relative to vaginal opening)
What problems can occur in relation to the greater vestibular glands?
Can become inflamed, infected and form of cysts or abscesses
What is the clitoris formed from?
Paired Corpora Cavernosa and bulb of vestibule
What nerve supplies the clitoris?
Sensory from Pudendal (S2-4)
What is an episiotomy?
Surgical incision of the perineum to widen the vaginal opening and facilitate delivery during childbirth
Most common incision is mediolateral
What layers does a mediolateral episiotomy cut through?
Posterior wall of vagina Transverse perineal muscles Bulbospongiosus Perinal membrane Levator Ani Perineal skin and subcutaneous tissue
What makes up the female reproductive tract?
Vagina, cervix, uterus, uterine tubes and ovaries
What peritoneal pouches are found in females?
Vesicouterine pouch (between bladder and uterus) Rectouterine pouch (between uterus and rectum)
What opening connects the vagina and the cervix?
External Os
What lines the uterine cavity?
Endometrium
What are the layers of the walls of the uterus?
Endometrium
Myometrium (thick, smooth muscle layer)
Perimetrium (outer, serosal layer)
Where do the uterine tubes open into and what is the clinical relevance of this?
Peritoneal cavity - egg can implant in peritoneal cavity causing ectopic pregnancy
What is the function of the fimbriae of the infundibulum?
Receive ovum at ovulation
Where do the ovaries develop from?
Intermediate mesoderm on posterior abdominal wall (approx. L2)
Which nerve runs close to the ovaries and can be impinged by ovarian pathology?
Obturator nerve - can be impinged causing pain/loss of sensation/ muscle wasting in medial thigh compartment
Which part of the broad ligament suspends the ovaries?
Mesovarium
What is contained within the suspensory ligament of the ovaries?
Ovarian vessels and lymphatics
What does the round ligament of the uterus connect?
Ovaries to the uterus (then runs from uterus to labia majora via the inguinal canal)
What are the round ligaments a remnant of?
Gubernaculum
What are the three areas of the broad ligament?
Mesometrium (related to uterus)
Mesosalpinx (related to uterine tubes)
Mesovarian (related to ovaries)
What is the broad ligament?
Large, double layered fold of peritoneum that surrounds and supports the uterus, uterine tubes and ovaries
What is the paracolpium?
Fascia around the vagina which connects to the tendinous arch - important for supporting the vagina
