PELVIS , PERINEUM, GYNAECOLOGY , ANATOMY, PELVIC DIAPHRAGM, PUDENTAL CANNAL, URETER, URETER COURSE, ABDOMINAL AND PELVIC URETER, BLOOD SUPPLY OF PELVIS, UTERO VAGINAL SUPPORT. BASIC SCIENCES.

1. ESSENTIAL ANATOMY IN OBG - I
Dr. M. GOKUL RESHMI
OBG

2. PELVIC BONE
The pelvic bone is divided into
• Ilium
• Ischium
• Pubic bone.

3. PELVIC BRIM
• The pelvic brim is the superior
opening of the pelvis or pelvic
inlet.
• It is bounded by:
• The sacral promontory
posteriorly
• The iliopectineal line (the ridge
going over the ilium and pectin
pubis) laterally
• Pubis symphysis anteriorly.

4. PELVIC BRIM
Structures pass over the pelvic
brim:
• superior rectal artery,
• gonadal arteries,
• ureters and
• psoas muscle.

5. PERINEUM
• The diamond-shaped space of
the bony pelvic outlet.
• The anterior triangle is called the
urogenital triangle.
• The posterior one is called the
anal triangle.

6. UROGENITAL TRIANGLE
It contains urogenital haitus and crura of
the clitoris.
The ischiocavernosus muscles arise from
the medial aspect of the ischial ramus and
enclose the crura of the clitoris.
The bulb of the vestibule is surrounded by
the bulbocavernosus muscle, which arises
from the perineal body and inserts into the
body of the clitoris. It interdigitates with the
external anal sphincter before its insertion.
The superficial and deep transverse
perineal muscles arise from the perineal
body and insert into the ischial ramus.
Bartholin’s gland and the urogenital
diaphragm also lie in the urogenital triangle.

7. UROGENITAL DIAPHRAGM
• The compartments are
superficial and deep perineal
pouch.
• The superficial pouch is
formed by the deep layer of
the superficial perineal fascia
(Colles fascia) and inferior
layer of the urogenital
diaphragm (perineal
membrane).
The contents are:
• superficial transverse perinei
(paired), bulbocavernosus
covering the bulb of the
vestibule,
• ischiocavernosus (paired)
covering the crura of the clitoris
• Bartholin’s gland (paired).

8. UROGENITAL DIAPHRAGM

9. UROGENITAL DIAPHRAGM
• The deep perineal pouch is
formed by the inferior and
superior layer of the urogenital
diaphragm—together called
urogenital diaphragm or
triangular ligament.
• Between the layers, there is a
potential space of about 1.25
cm.
The contents are:
• Deep transverse perinei (paired)
and sphincter urethrae
membranaceae.
• Both the pouches contain
vessels and nerves

10. UROGENITAL DIAPHRAGM
• Urogenital diaphragm – the sheath of
muscle enclosed between the two
triangular fascial membranes.
• The superior layer is thin and the
inferior layer is tough and fibrous.
• It lies inferior to the pelvic diaphragm.
• Posteriorly, it encloses the deep
transverse perineal muscle and
anteriorly, it encloses the urethral
sphincter.

11. PELVIC DIAPHRAGM
• The muscles of the pelvic
diaphragm and their
attachments to the bony pelvis.

12. PELVIC DIAPHRAGM
The divisions of the levator ani
muscles (superficial plane
removed on the right).

13. PELVIC DIAPHRAGM
• The pelvic diaphragm and
superior fascia of the urogenital
diaphragm.
• The muscles include the deep
transverse perineal and
sphincter urethrae.

15. ISCHIORECTAL FOSSA
• Ischiorectal fossa is a triangular spaces,
which contain fat.
• The apex Levator ani muscle,
• Laterally Obturator internus muscle,
• Medially Anal canal,
• Posteriorly Gluteus maximus muscle
and sacrotuberous ligament,
• The base Perineal skin.

16. PUDENDAL / ALCOCK’S CANAL
• The pudendal canal contains the
pudendal artery, pudendal vein and
pudendal nerve.
• It runs in the lateral wall of the
ischiorectal fossa and medial to the
obturator internus muscle.

17. PUDENDAL CANAL
• It travels out through the greater sciatic
foramen and is in close association with
ischial spines (lateral to ischial spines).
• It travels back through the lesser sciatic
foramen and runs along the medial
aspect of the ischiopubic ramus.

18. COURSE OF URETER IN THE ABDOMEN AND
PELVIS
• The abdominal part lies on the
psoas major and anteriorly
crosses the genitofemoral nerve.

19. COURSE OF URETER IN THE ABDOMEN AND
PELVIS
• It then enters the pelvis (passes
the pelvic brim along the
posterior wall) in front of the
common iliac or external iliac
vessels.
• It follows the anterior border of
the greater sciatic notch and
turns medially at the ischial
spines.

20. COURSE OF URETER IN THE ABDOMEN AND
PELVIS
• It then runs in the base of the
broad ligament before it reaches
the bladder.
• In the broad ligament (mainly
parametrium) the uterine artery
crosses the ureter superiorly
(often termed ‘water under the
bridge’) before entering the
uterus.

21. COURSE OF URETER IN THE ABDOMEN AND
PELVIS
• The ureter then runs above the
lateral fornix of the vagina (2cm
lateral to the cervix) and turns
medially in front of the vagina to
enter the bladder.
• It is retroperitoneal in most of its
course except towards the ending
before entering the bladder. The
nerve supply comes from the
sympathetic nerves (T11 to L1).

22. URETER
• The ureter is recognized by the
following features:
i. Pale glistening
appearance.
ii. longitudinal vessels on
the surface.
iii. Peristalsis.

23. URETERIC DAMAGE DURING HYSTERECTOMY
• Because of its close relationship to the cervix, the vault of the vagina
and the uterine artery, the ureter may be damaged during
hysterectomy.
• Apart from being cut or tied, in radical procedures, the ureter may
undergo necrosis because of interference with its blood supply.
• It may be displaced by scar tissue or by fibromyomata or cysts that
are growing between the layers of the broad ligament and may suffer
injury if its position is not noticed at surgery.

24. BLOOD SUPPLY
• Common iliac artery
External iliac artery Internal iliac artery

25. BLOOD SUPPLY
• Internal iliac artery
Anterior division Posterior division
• Superior vesical
• Uterine
• Inferior vesical
• Middle rectal
• Vaginal
• Inferior gluteal
• Obturator
• Internal
pudendal
• Superior gluteal
• Iliolumbar
• Lateral sacral
v
p
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27. UTERO VAGINAL SUPPORT
Level Site of vagina Structures involved Type of defects
I Upper Ligaments
• Uterosacr
• Mackenrodt
Prolapse
•Uterovaginal
• Enterocele
• Vaginal vault
Ii Middle Fascia
• Arcus tendineus
• Pubocervical
Defects
• Paravaginal
• Pararectal
Iii Lower Urogenital diaphragm
Perineal muscles perinal body
Levator plate
• Cystocele
• Rectocele
• Urinary incontinence

28. UTERO VAGINAL SUPPORT

29. OVARIES
• Ovaries are located in the
ovarian fossa .
• Anterior boundary is the
obliterated umbilical artery
• Posterior boundary is the ureter
and internal iliac artery.

30. OVARIES
• The ovaries are held in position
by the ovarian ligament and
suspensory ligament.
• The surface of the ovary is lined
by cuboidal cells (germinal
epithelium) and beneath this is
tunica albuginea.

31. OVARIES
• The ovary has a cortex (contains
follicles and corpora lutea) and
vascular medulla.
• The ovum is released into the
peritoneal cavity at mid-cycle
and is picked up by the fimbrial
end of the fallopian tube.

32. OVARIES
• The major blood vessels enter the
ovary at the ovarian hilum.
• Both ovarian arteries arise from
the abdominal aorta.
• The left ovarian vein drains into left
renal and right ovarian vein drains
into inferior vena cava.
• The lymphatics of the ovary drain
into the para-aortic nodes.

33. OVARIES
• The parasympathetic nerve
supply comes from the vagus
nerve and the sympathetic nerve
supply comes from T10 (lesser
splanchnics, via the hypogastric
to the ovarian plexus).

34. THANK YOU…