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

• • • • • •

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 Preperitoneal fat Peritoneum

– Parietal peritoneum peritoneum of anterior abdominal wall Visceral peritoneum peritoneum investing the viscera

Anatomy: Perineum

• • • • • • • 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) 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

Obturator Internus

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

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. ischiocavernosus M. bulbospongiosus M. transversus perinei superficialis

Perineal muscles

M. sphincter ani externus Urethra Vagina

Urethra Vagina M. transversus perinei profundus Urogenital fascia M. transversus perinei superficialis M. sphincter ani externus

Pelvic floor

ATFP

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: – 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)

• • • • • • • Mons pubis Labium majus Labium minus Clitoris Bulbus vestibuli Gl. vestibularis major Gl. vestibulares minor

Labium Majus Pudendi

• • • • • • Correspond to the scrotum Includes numerous hairs Rima pudendi Commisura labiorum ant. Lig.rotundum

Commissura post

Labium Minus Pudendi (Nymphae)

• • • • • • • Includes sweat glands Preputium clitoridis Frenilum clitoridis Sulcus nympholabialis Sulcus nympholabialis Frenulum labiorum pudendi Fossa navicularis Fourchette 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

• • • • Vagina Uterus Uterine tubes Overies

Vagina (Kolpos)

• • • • • • • • 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

• • • • • 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

• • • • • 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

Anterior Division Uterine Umbilical Uterine vesical Obturator Internal pudendal Inferior gluteal Middle vesical Middle rectal Vaginal Branches of the Internal Iliac Artery Posterior Division Superior gluteal Lateral sacral Iliolumbar

Collateral Arterial Circulation of the Pelvis

Primary Artery Aorta

Ovarian artery Superior rectal artery (inferior mesenteric artery) Lumbar arteries Vertebral arteries Middle sacral artery

External Iliac

Deep iliac circumflex artery Inferior epigastric artery

Femoral

Medial femoral circumflex artery Lateral femoral circumflex artery

Collateral Arteries

Uterine artery Middle rectal artery Inferior rectal artery (internal pudendal) Iliolumbar artery Iliolumbar artery Lateral sacral 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

Lig.Latum Uteri Lig.Rotundum

– Cyst of Nuck canal – A.Sampson – Lig. Cardinale

important lig.

most

(LUNA)

8 Avascular Spaces

• • • • • • 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

Obturator Foramen Lumbar Pleksus Sacral Pleksus Genitofemoral n.

Obturator n.

Femoral n.

Pudendal n.

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

LH Thecal cell

Erken Foliküler Faz Androstenedione Testosterone

FSH Granulosa cell E1

Aromatisation IGF II

E2

Asetat Kolesterol Sitokrom P450 scc Pregnanolon 17 α OH ase 17 OH Pregnanolon 17-20 Desmolase DHEA 17 β OH SDH Androstenediol Progesteron 17 α OH ase 17 OH Progesteron 17-20 Desmolase Androstenedion 17 β OH SDH Testosteron 5 α redüktase DHT E3 ?

E1 17 β OH SDH E2

• • • •

Gonadotropin Releasing Hormone (GnRH)

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 )

• • • • 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)

• • • • 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