Introduction to
Obstetrics and Gynecology
Anatomy and Physiology
Assoc. Prof. Gazi YILDIRIM, M.D.
Objectives
• To learn
– female reproductive anatomy
– Pelvic anatomy
– Pelvic innervation
– Pelvic blood supply
– Basic hormon knowledge
– Steroid hormon pathways
– Female reproductive endocrinology
Abdominal Wall
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Skin
Subcutaneous fat (superficial fascia), which below the navel can be considered as
two layers:
– Camper’s fascia; the superficial layer containing fat,
– Scarpa’s fascia; fibroelastic membrane.
•
Muscles, The abdominal muscular wall can be considered a group of 4 paired
muscles along with their aponeurosis:
– The three lateral muscles (from superficial to deep) are the
• External abdominal oblique
• Internal abdominal oblique
• Transversus abdominis muscle
– Medially muscles are the:
• Rectus Abdominis
• Pyramidalis muscles
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Preperitoneal fat
Peritoneum
– Parietal peritoneum peritoneum of anterior abdominal wall
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Visceral peritoneum peritoneum investing the viscera
Anatomy: Perineum
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Clitoris
Urethra
Vagina
Anus
Labia majora and minora
Bartholin’s and Skene’s glands
Hymen
Elements comprising the Pelvis
• Bones
– Ilium, ischium and pubis fusion
• Ligaments
• Muscles
– Obturator internis muscle
– Arcus tendineus levator ani or white line
– Levator ani muscles
– Urethral and anal sphincter muscles
Bony pelvis
• Composition: formed by paired
hip bones, sacrum, coccyx, and
their articulations
• Two portions
– Greater pelvis
– Lesser pelvis
• Terminal line ( pelvic inlet):
formed by promontory of
sacrum, arcuate line, pectin of
pubis, pubic tubercle, upper
border of pubic symphysis
• Pelvic outlet: formed by tip of
coccyx, sacrotuberous ligament,
ischial tuberosity, ramus of
ischium, inferior ramus of pubic
symphysis
Anatomy: Bones of Pelvis
• Sacrum
• Coccyx
• Innominates (2)
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Ilium
•
Ischium
•
Pubis
• Anatomical antero-posterior diameter (true conjugate) = 11cm
• Obstetric conjugate = 10.5 cm (-2cm from diagonal conj)
• Diagonal conjugate = 12.5 cm
Pelvic Floor Muscles
Levator Ani
•Puborectalis
•Pubococcygeus
•Ileococcygeus
Obturator
Internus
Piriformis
Coccygeus
Levator Plate
Netter F Atlas of Human Anatomy Novartis 1997
“Ligaments and Fascia”
Cardinal/Uterosacral Complex
(Delancy level I)
Paracervical Ring
Arcus Tendineus Fascia Pelvis ATFP
Pubocervical “fascia”
Rectovaginal “fascia”
Perineal Body
Perineal
Membrane
Superficial
Pyramidal
Internal
External
Transverse
Anal
Fibrous
AnalSphincter
Sphincter
perineus
Body sphincter)
Bulbocavernosis
(urethrovaginal
Cleveland Clinic Foundation
Burnett Novack’s Gynecology 2004
• Sphincter urethrae
externus
• Bulbospongiosus
• Ischiocavernosus
• Transversus
perinei profundus
• Transversus
perinei
superficialis
Bony
structures
of a pelvis
M.
Urethra
ischiocavernosus
M.
bulbospongiosus
M. transversus
perinei
superficialis
Perineal
muscles
M. sphincter
ani externus
Vagina
Urethra
Vagina
M. transversus
perinei
profundus
Urogenital
fascia
M. transversus
perinei
superficialis
M. sphincter
ani externus
ATFP
Pelvic
floor
Add
rectum
Rectal
connections
Vaginal
connections
Urethra
Bladder
Cervix
lig.cardinale
Lig.
sacrouterina
Lig. cardinale
Layers of the Anterior Triangle of
the Perineum
• Skin
• Subcutaneous tissue
.Camper's fascia
.Colles fascia
• Superficial space
.Clitoris and its crura
.Ischiocavernous muscle
.Vestibular bulb
.Bulbocavernous muscle
.Greater vestibular gland
.Superficial transverse perineal muscle
• Deep space-perineal membrane
.Compressor urethrae
.Urethrovaginal sphincter
• Ürogenital trigon:
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M. Transversus perinei superficialis
M. İschiocavernosus
M. Bulbocavernosus
M. Transversus perinei profundus
• Anal trigon:
– M. Levator ani
– M. Sphincter ani externus
FIGURE 7.2. Superficial compartment and
perineal membrane.
EKSTERNAL ACCESSORY ORGANS
(Vulva – Pudendum)
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Mons pubis
Labium majus
Labium minus
Clitoris
Bulbus vestibuli
Gl. vestibularis
major
• Gl. vestibulares
minor
Labium Majus
Pudendi
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Correspond to the scrotum
Includes numerous hairs
Rima pudendi
Commisura labiorum ant.
Commisura labiorum post.
Lig.rotundum
Rima pudendi
Commissura post
Labium Minus Pudendi
(Nymphae)
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Includes sweat glands
Preputium clitoridis
Frenilum clitoridis
Sulcus nympholabialis
Frenulum labiorum pudendi
Fossa navicularis
Fourchette
Sulcus nympholabialis
Frenulum labiorum
pudendi
Frenulum clitoridis
Clitoris
• Corresponds to the
male penis
• Corpus, crus, glans
• Attach to the side of the
pubic arch with Lig.
Suspansorium
Vestibüle - Introitus
(Vestibulum Vaginae)
• The Vaginae and ostium
urethra externa opens
vestibüle
• Covered by stratified
squamous epithelium
Vestibül
Glandula Vestibularis Major
(Bartholin’s glands)
• Correspond to the male
bulbourethral glands
• Covered by
M.bulbocavernosus
• Secrete fluid that moistens
and lubricates vestibule
Glandula Vestibularis Minor
(Skene glands)
• Opening either side of the
urethra
• To get Gonore retansiyon
abscess
Skene kanalları
FIGURE 7.2. Superficial compartment and
perineal membrane.
Hymen Feminus
• Mucosal fold
• Carunculae myrtiformis
Anatomy: Pelvic Innervation
• Pelvic splanchnic nerves from 2nd to 4th
sacral nerves
• Pudendal nerve supplies vulva and lower
vagina
• Vulva blood supply
comes from a
terminal branch of
the a.iliaca interna a.pudenda interna
• N. pudendus
INTERNAL ACCESSORY ORGANS
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Vagina
Uterus
Uterine tubes
Overies
Vagina (Kolpos)
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Fibromuscular tube about 9 cm
Fornix vaginae
Columna rugarum
Tunica mucosa
Tunica muscularis
Tunica adventisya
A. vaginalis
V. iliaca interna
Vajina
Uterus (Metra - Hystera)
• 8 x 6 x 4 cm 40-50 g.
• Corpus, isthmus, collum (cervix)
• Portio vaginalis uteri
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Serosal layer (perimetrium)
Muscular layer (myometrium)
Mucosal layer (endometrium)
Excavatio vesicouterina
Excavatio rectouterina (Douglas )
Squamocolumnar Junction
Tuba Uterina
(Fallop Tüpleri-Salpinx)
• İnfundibulum (fimbria, fimbriae ovarica) pars ampullaris,
isthmica, interstitialis
• A.ovarica ve A.uterina
Ovaries
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Medulla (blood and lenf vessels, nerves)
Cortex (germinal epitel, tunica albuginea, hilum ovarii)
Lig. Ovarii Proprium (between overies and uterus)
Lig. Suspensorium Ovarii (infundibulopelvic) (between overies and pelvic
side wall)
• A.ovarica, plexus pampiniformis
Pelvic Vasculature
Common Iliac
Sakralis Media
İnternal iliak (hipogastrik)
İliolumbar
Lateral Sakral
Superior Gluteal
Inferior Gluteal
Orta Hemoroidal
Pudendal
Uterin
Inferior Vesika
Umbilical
Obturator
Burnett Novack’s Gynecology 2004
Branches of the Internal Iliac Artery
Anterior Division
Posterior Division
Uterine
Umbilical
Uterine vesical
Obturator
Internal pudendal
Inferior gluteal
Middle vesical
Middle rectal
Vaginal
Superior gluteal
Lateral sacral
Iliolumbar
Collateral Arterial Circulation of the Pelvis
Primary Artery
Collateral Arteries
Aorta
Ovarian artery
Uterine artery
Superior rectal artery
(inferior mesenteric artery)
Middle rectal artery
Lumbar arteries
Vertebral arteries
Inferior rectal artery (internal pudendal)
Iliolumbar artery
Iliolumbar artery
Middle sacral artery
Lateral sacral artery
External Iliac
Deep iliac circumflex artery
Inferior epigastric artery
Femoral
Medial femoral circumflex artery
Lateral femoral circumflex artery
Iliolumbar artery
Superior gluteal artery
Obturator artery
Obturator artery
Inferior gluteal artery
Superior gluteal artery
Iliolumbar artery
• Ovarian arteries
– Originate directly from the
aorta, inferior to the renal
arteries.
– Most frequently identified at
the IP ligament.
• Ovarian veins:
– Left ovarian vein drains into
the left renal vein
– Right ovarian vein drains
directly into the inferior vena
cava.
Ligaments of the Uterus
• Lig.Sacrouterinum (LUNA)
• Lig.Latum Uteri
• Lig.Rotundum
– Cyst of Nuck canal
– A.Sampson
– Lig. Cardinale most
important lig.
8 Avascular Spaces
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Prevesical (1)
Vesicouterine (1)
Rectovaginal (1)
Presacral (1)
Paravesical (2)
Pararectal (2)
Lymph Drainage
• The external genitalia, anus, and anal canal
drain to the superficial inguinal nodes
• The lower one third of the vagina drains to the
sacral nodes and the internal and common
iliac nodes
• The cervix drains to the external or internal
iliac and sacral nodes
Lymph Drainage
• The lower uterus drains to the external iliac
nodes
• The upper uterus drains into the ovarian
lymphatics to the lumbar nodes. The
lymphatics of the ovaries drain out of the
pelvis to the lumbar nodes
Lymph Drainage
• Cervical Cancer:
– Drains 1st to the parametrial nodes --> obturator nodes -->
pelvic nodes --> para-aortic
• Uterine Cancer:
– Drains 1st to the pelvic nodes or para-aortic.
• Ovarian Cancer:
– Can metastasize to either the pelvic or para-aortic nodes.
Pelvic Autonomics
• Superior hypogastric
plexus (presacral nerve)
– Contains no
parasympathetics
• Hypogastric nerve
• Inferior hypogastric plexus
– Contains parasympathetic
fibers from the pelvic
splanchnics
• Ganglion impar
Pelvik Organların Sinirleri
Pelvik Organların Sinirleri
Pelvic Vasculature
Common Iliac
Sakralis Media
İnternal iliak (hipogastrik)
İliolumbar
Lateral Sakral
Superior Gluteal
Inferior Gluteal
Orta Hemoroidal
Pudendal
Uterin
Inferior Vesika
Umbilical
Obturator
Burnett Novack’s Gynecology 2004
Pelvic Innervation
Lumbar Pleksus
Sacral Pleksus
Genitofemoral n.
Obturator n.
Femoral n.
Pudendal n.
Obturator Foramen
Sciatic n.
Hipogastrik Plexus
(Otonomic)
Pelvik Plexus
(Otonomic)
Irvin W Obstetrics/Gynecology 2003
Folliculogenesis and
Normal Physiology
Follicular Maturation
FSH
• Induces early growth
• Controls follicle number
LH
• Provides estrogen precursors
• Needed for latter stages of growth
Erken Foliküler Faz
Thecal cell
LH
Androstenedione
Testosterone
Granulosa cell
FSH
IGF II
Aromatisation
E1
E2
Asetat
Kolesterol
Sitokrom P450 scc
Progesteron
Pregnanolon
17 OH Pregnanolon
17-20 Desmolase
17 α OH ase
3 β OH SDH
17 α OH ase
17 OH Progesteron
17-20 Desmolase
Androstenedion
DHEA
17 β OH SDH
Androstenediol
E3
17 β OH SDH
Testosteron
5 α redüktase
DHT
?
E1
17 β OH SDH
E2
Gonadotropin Releasing Hormone
(GnRH)
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Secreted by hypothalamus
Pulsatile secretion is critical for activity
GnRH secretion inhibited by estrogen
Low levels of estrogen cause hypothalamus to
release GnRH
Follicle-stimulating Hormone (FSH )
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FSH hormone is secreted by anterior pituitary
Turned on by GnRH
Negative feedback inhibition with estrogen
Causes maturation of dominant ovarian
follicle
Luteinizing Hormone (LH)
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Secreted by anterior pituitary
Turned on by estrogen
Maintains corpus luteum
Causes corpus luteum to secrete progesterone
Positive feed back of E2
more than 200 pg /ml
> 50 hours
A threshold of LH
14-27hours
for full maturation of the oocyte to occur
The End