● Uterus
– A pear shaped, thick
walled, muscular organ
– Situated between bladder
and rectum
– 7-8 cm long, 4-5 cm wide,
2-3 cm thick
isthmus
Uterus
● Divided into 2 main portions
– Body/Cervix
Ratio: adult, 2:1, infant, 1:2
– isthmus
● a transitional zone between body and cervix
● Special obstetrical significance (lower uterine
segment)
● Internal orifice(os)
– anatomical internal os: narrowest position of the cavity
– histological internal os
the columnar epithelium changes into endometrium
isthmus
Uterus
● Divided into 2 main portions
– Body/Cervix
Ratio: adult, 2:1, infant, 1:2
– isthmus
● a transitional zone between body and cervix
● Special obstetrical significance (lower uterine
segment)
● Internal orifice(os)
– anatomical internal os: narrowest position of the cavity
– histological internal os
the columnar epithelium changes into endometrium
isthmus
uterus
– body (superior 2/3s)
● Fundus: the widest place of the corpus
● Lined with endometrium
– cervix (inferior 1/3)
● Supravaginal portion
● Vaginal portion
● External cervical os
● Squamocolumnar junction
– The cervical canal is covered
by columnar epithelium
– The surface of vaginal portion is
covered by squamous epithelium
External cervical os
4
4
1
3
3
7
2
5
5
2
6
Figure: internal organs in female pelvis. 1. uterus, 2. ovaries, 3. fallopian
tubes, 4. round ligaments, 5. utersacral ligaments, 6. rectouterine pouch
(pouch of Douglas) , 7.broad ligaments.
fundus
cavity
isthmus
corpus
cervix
fornix
External os
Anatomical os.
Histologic os.
Supra-vaginal
Vaginal part
vagina
Sagittal view
Coronary view
uterus
Position and Axis Direction
anteversion:
tipped forward
anteflexion: the fundus is pointing
forwards. The isthmus is bend.
retroversion
tipped backwards
retroflexion: the fundus is pointing
backwards. Anterior of uterus is
convex.
The wall of the uterus
perimetrium (serous): peritoneal covering
myometrium (muscular): the out layer, the inner layer
the endometrium(mucous): soft and spongy
1
2
The myometrium of the uterus:1. the out layer,
2. the inner layer
SUPPORTS OF UTERUS
INTRODUCTION
● The normal position & support of
uterus, vagina, bladder & rectum
rely on interdependent system of
bony, muscular & connective tissue.
● Subtle alterations in one, lead to
failure of normal anatomy.
● Understanding of normal applied
pelvic anatomy is esential in repair of
pelvic organ prolapse.
Classification of Supports of Uterus
● Primary supports
1} muscular or active
a) pelvic diaphragm
b) urogenital diaphragm
c) perineal body
2} fibromuscular or mechanical
a} uterine axis
b} round ligament of uterus
c} endopelvic fascia
● Secondary supports
a} broad ligaments
b} UV fold of peritoneum
c} rectovaginal fold of peritoneum
Pelvic diaphragm
● Consists of 2 levator ani muscles
● Each levator ani consists of 3 divisions
pubococcygeus
iliococcygeus
ischiococcygeus / coccygeus
● Covered superiorly & inferiorly by pelvic fascia
which separates it from parametrium above &
ischiorectal fossa below.
● Levator ani fix the perineal body & make it as an
anchor for levator ani.
Pubococcygeus
● Origin- posterior surface of body of pubis.
● Insertion- into the anococcygeal raphe & coccyx
by passing backwards, lateral to vagina &
rectum.
● Some of the inner fibres form
puborectalis, pubovaginalis, perineal body.
● Nerve supply- inferior rectal nerve s3-4
● Fibres near perineal body divide the space
anterior- hiatus urogenitalis- urethra & vagina
posterior- hiatus rectalis- rectum
Iliococcygeus
● Fan shaped muscle
● Origin- broad margin along the white
line of pelvic fascia known as arcus
tendineus levator ani.
● Insertion- into the coccyx by passing
backwards & inwards from the origin.
● Nerve supply- inferior rectal nerve s34.
Ischiococcygeus / coccygeus
● Origin- narrow origin from ischial
spine.
● Insertion- in front of coccyx by
spreading out posteriorly from the
origin.
● Nerve supply- supplied by s4-5.
Applied anatomy
● Perineal tears during parturition
● Postmenopausal state
● Perineal nerve injury
● Asthenic states
● Levator ani constitutes pelvic
diaphragm, support pelvic viscera,
● Assist ant abdominal wall muscles in
containing abdominal & pelvic
contents
● Supports post wall of vagina
● Facilitates defecation
● Aids in fecal continence
● During parturition supports fetal head
and helps in internal rotation of head.
How levator ani helps in containing pelvic
viscera?
● Contraction of levator ani pulls the
rectum and vagina towards pubis
● Thereby kinking the rectum and
narrowing vagina anteroposteriorly
preventing its descent.
How levator ani helps In internal rotation?
● With contraction of levator ani
posterior attachments are pulled
towards pubis which help in internal
rotation of presenting part.(?)
● Uterine contraction pushes presenting
part down & cause muscle to contract.
● Lowest part of fetus is carried
forwards during contraction & ant
fibres are directed inwards & forwards.
Examination of levator muscle tone?
● Levator ani tone is examined by
placing two fingers in vagina & is
flexed laterally, the thumb being
applied externally over labium majus.
● Patient is asked to contract her pelvic
floor muscles and thus levator
muscles can be palpated to determine
its tone & assess size of hiatus
urogenitalis.
Kegel ‘ exercises
● Quick pumps- 15 reps of quick pumps,
pause for 30 sec and repeat. Start at
15 and work upto 100 two times a day.
● Hold & release- contract the muscle
slowly & hold for 5 sec, release slowly.
Work your way to atleast 25 reps two
times a day.
● Elevator- slowly contract 1/3 of way,
pause, then 2/3 rd of way, pause then
all the way. Do 10 reps two times a
De Lancey s levels of
vaginal support
● Level 1- suspension by ligaments of
paracolpium.
damage to it results in uterovaginal
prolapse, post hysterectomy vaginal
prolapse, enterocele.
the cause is at or above the level of
ischial spines.
primary loading bearing elements are
uterosacral & lesser extent cardinal lig
● Level 2- due to lateral attachment of
fascial septa to pelvic sidewalls.
the septa attach to arcus tendineus
fascia pelvis & arcus tendineus fascia
rectovaginalis.
damage to it results in paravaginal &
pararectal defects.
● Level 3- attributed to fusion to the
urogenital diaphragm anteriorly &
proximal perineum posteriorly.
damage to it result in urinary
incontinence anteriorly & perineal
body defects posteriorly.
cystocele & rectocele are central
defects.
Urogenital diaphragm
● Also known as triangular ligament.
● Not so well developed in females as in males.
● Enclosed superiorly & inferiorly by fascia
through which urethra & vagina pass.
● Inferior fascia of the diaphragm is known as
perineal membrane.
● It is triangular sheet of dense fibromuscular
tissue that spans ant half of pelvic outlet.
● Muscles include deep transverse perinei
sphincter urethrae
● Reinforce with pelvic diaphragm anteriorly.
Deep transverse perinei
● Origin- medial aspect of ischiopubic
rami
● Insertion- lower part of the vaginal
wall, ant fibres blend with those of
sphincter urethrae.
● Action- steadies the central perineal
tendon
● Nerve supply- perineal nerve s2-4.
Sphincter urethrae
● Origin- medial aspect of ischiopubic
rami
● Insertion- urethra & vagina
● Action- compresses the urethra
● Nerve supply- perineal nerve s2-4
Applied anatomy
● Lower tier support for uterus along
with pelvic diaphragm & perineal body.
● Perineal nerve injury cause atonicity
of muscles- contributory factor for
prolapse.
● Provides support to posterior vaginal
wall by attaching perineal body &
vagina and in turn perineal body to
ischiopubic rami limiting downward
Perineal body
● Also known as central point of tendon.
● Triangle shaped structure
● Fibromuscular node situated in median plane
about 1.25 cms in front of anus.
● Formed by tendinous attachments of
bulbocavernosus
external anal sphincter
superficial transverse perinei
● Central connection to both pelvic & urogenital
diaphragm and posteriorly to anococcygeal
raphe.
Applied anatomy
● Important in females for support of
pelvic organs.
● May be damaged during childbirth
resulting in prolapse of pelvic organs.
● In posterior colpoperineorrhaphy, the
perineal body is artificially
constructed.
Perineal tear
● First degree- involves remnants of
hymen,
fourchette, lower part of
vagina
& perineal skin. Perineal
body is
intact
● Second degree- involves posterior
vaginal
● Third degree- involves post vaginal
wall, perineal body, anal sphincter
complex.
excluding anal canal or rectum
● Fourth degree- involving anal
sphincter complex with anal & rectal
mucosa involvement.
Episiotomy
● Inflicted second degree perineal injury
● Structures cut are
post vaginal wall
sup & deep transverse perinei
bulbospongiosus
part of levator ani
fascia covering these muscles
transverse perineal branches of pudendal
vessels & nerves
subcutaneous tissue & skin
Uterine axis
● Anteverted position of uterus itself prevents the
organ from sagging down through vagina.
● Increase in intra abd pressure tends to push
uterus against bladder & pubis which further
accentuates anteversion.
● Angle maintained by uterosacral & round
ligament of uterus.
● Anteversion 90 degree and
anteflexion 120 degree
● Roughly long axis of uterus
corresponds to the axis of pelvic inlet
● And axis of vagina correspnds to axis
of pelvic cavity & outlet.
• Applied anatomy
uterine prolapse usually starts with
retroversion of uterus and hence its
importance.
Round ligament of uterus
● Two fibromuscular flat bands 10-12 cms long.
● Lies between 2 layers of broad lig anteroinferior
to uterine tube.
● Begins at the lateral angle of uterus ,
runs forwards & laterally,
passes through deep inguinal ring,
traverses inguinal canal and
merges with areolar tissues of labium majus
after breaking up into thin filaments.
Applied anatomy
● It keeps the fundus of uterus pulled
forwards & maintain the angle of
anteversion against the backward pull
of the uterosacral ligaments.
● Lymphatics from fundus of uterus
pass along it to the superficial inguinal
nodes.
● Round ligament is plicated to facilitate
anteversion in conservative
Endopelvic fascia
● Connective tissue of the pelvis
● Consists of loose areolar tissue containing
varying aounts of smooth muscle.
● Bounded above- peritoneum
below- sup fascia covering levator ani
lateral- pelvic wall fascia
medial- supports & invests midline
organs such as uterus & upper part of vagina.
● At various locations act as loose areolar tissue
capable of distension, neurovascular sheaths,
septa & ligaments that support & separate the
pelvic organs.
● Between different layers are bloodless spaces
which are important to identify in vaginal plastic
operations & oncosurgery.
● Endopelvic fascia divided into 3 parts
parietal fascia- obturator, levator ani,
coccygeus & piriformis
visceral fascia
deep endopelvic connective tissueuterosacral lig
cardinal lig
pubocervical lig
pubocervical & rectovaginal
septum / fascia
pericervical ring
Parietal pelvic fascia
● Obturator fascia- well defined in area superior to
the arcus tendineus levator ani & below linea
terminalis.
it represents a vestigial portion of levator ani
whose origin has been lowered through
evolution to the level of muscular arch.
● Levator ani fascia- this fascia is continous
across the pelvic floor blending laterally with
obturator fascia at arcus tendineus levator ani
and centrally with levator plate & visceral fascia
at the urogenital hiatus.
● Coccygeus fascia (sacrospinous ligament)this important pelvic support structure
extends from ischial spine lateraly to the sacrum
medially.
important alternative source of proximal
support when uterosacral ligament is
unavailable or insufficient.
it is also important in repair of vault prolapse
by transvaginal sacrospinous colpopexy.
● Piriformis fascia- this is the thinnest fascia and
most posterior of the fascia of pelvis.
Visceral pelvic fascia
● These are loose highly elastic ill defined
encasements of central pelvic organs which
allow for high degree of physiologic distension
necessitated by the function of pelvic organs.
● They blend intimately with organs that they
encase.
● Structures invested by it are
uterus, vagina, bladder & rectum.
● Structures not invested by it are
fallopian tube, ovaries
Deep endopelvic connective tissue
● Central importance in the applied anatomy of
pelvis & significant for pelvic reconstructive
surgery.
● The six pericervical ligaments form the
paracolpium.
● Net effect is suspension of the cervix in the
posterior pelvis, placement of upper 2/3 rd of
vagina directly over the levator plate and away
from direct exposure to urogenital hiatus.
● In normal anatomic position, pressure from
above tends to close the vaginal vault & results
in no tendency towards prolapse.
● The two fascia/ septa & their supports when
intact, the vaginal & rectal axis have a posterior
angle of 30 degree at anterior point of their
suspension over levator plate.
● Proximal 2/3 of vagina is nearly horizontal &
suspended over levator plate.
● Distal 1/3 of vagina below puborectalis muscle,
the vagina is nearly vertical as it passes through
urogenital hiatus.
● The normal vaginal axis is oriented posteriorly
toward a point just above the centre of 4 th
sacral vertebrae which is at the level of origin
uterosacral ligaments.
● The six pericervical ligaments are
uterosacral lig
cardinal lig
pubocervical lig
pubocervical septum
rectovaginal septum
pericervical ring
Uterosacral ligaments
● Origin- periosteum of sacral vertebrae
2, 3 & 4
● Insertion- on the posterior & lateral
supravaginal cervix at 5 & 7 o ‘clock
position. It is continous with & form
part of pericervical ring.
● Neurologic content- uterosacral plexus
of autonomic nerves
● Vascular content- minimal
● Muscular content- rectouterine muscle
● Function- these are primary proximal
suspensory elements of uterovaginal
complex.
they hold the cervix in
posterior pelvis at the level of ischial
spines with the uterus in anteflexion
and the vagina suspended over
levator plate.
the uterosacral lig blend as
continous structure superiorly &
laterally with cardinal ligaments and
Cardinal ligaments
● Origin- lateral pelvic walls
● Insertion- inserted on the lateral supravaginal
cervix at 3 & 9 o’ clock positions. It is also
continous with & form part of pericervical ring.
● Neurologic content- portions of uterosacral
plexus
● Vascular content- cervical branch of uterine
artery & veins.
● Muscular content- minimal smooth muscle
content.
● Urinary- distal ureter passes under
uterine artery within the superior
portion of cardinal ligament.
● Function- these are the primary
vascular conduits ot the uterus &
vagina, provide lateral stabilization to
the cervix at the level of ischial spines.
Applied anatomy of endopelvic fascia
● The ureter passes through the parametrium via
ureteric tunnel in an anteroposterior direction
about 1 cm lateral to cervix to reach the bladder.
and passes below the level of uterine vessels
which cross the ureter as they run transversely
through the pelvis to reach uterus.
● Sympathetic nerve ganglia & nerve fibres are
plentiful in parametrium.
● Lymphatics from upper 2/3 rd of vagina & uterus
fallopian tube pass through pelvic cellular
tissue.
● In CA Cervix > stage 2b cancer cells infiltrate
the parametrium and spread laterally along
cardinal ligament and posteriorly along
uterosacral ligaments.
● Factors which prevent prolapse of pelvic organs
are seen in cases such as
endometriosis
cancerous spread to endopelvic fascia
after radiotherapy
pelvic tumor preventing the descent.
●
●
●
●
Blood supply
The uterus is supplied by arterial blood both from the uterine
artery and the ovarian artery. Another anastomotic branch may
also supply the uterus from anastomosis of these two arteries.
Nerve supply
Afferent nerves supplying uterus are T11 and T12.
Sympathetic supply is from hypogastric
plexus[disambiguation needed] and ovarian plexus.
Parasympathetic supply is from second, third and fourth sacral
nerves.
References
● Te Lindes operative gynecology
● Novak s gynecology
● Shaw s Text book of gynecology
● Gray s anatomy
● Chaurasia s human anatomy
● Dutta obstetrics & gynecology
Textbook
THANK YOU