Introduction to Obstetrics and Gynecology Anatomy and Physiology

Introduction to Obstetrics and Gynecology Anatomy and Physiology Assoc. Prof. Gazi YILDIRIM, M. D.

Objectives • To learn – female reproductive 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 of anterior abdominal wall • Visceral 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) = 11 cm • Obstetric conjugate = 10. 5 cm (-2 cm 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 Anal. Sphincter Body perineus Bulbocavernosis (urethrovaginal sphincter) Cleveland Clinic Foundation Burnett Novack’s Gynecology 200

• 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: – – 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. Commisura labiorum post. Lig. rotundum Rima pudendi Commissura post

Labium Minus Pudendi (Nymphae) • • 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 2 nd to 4 th 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 Sakralis Media İnternal iliak (hipogastrik) Common Iliac İliolumbar Lateral Sakral Superior Gluteal Inferior Gluteal Orta Hemoroidal Pudendal Uterin Inferior Vesika Umbilical Obturator Burnett Novack’s Gynecology 20

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 Aorta Ovarian artery Superior rectal artery (inferior mesenteric artery) Lumbar arteries Vertebral arteries Collateral Arteries Middle sacral artery Lateral sacral artery External Iliac Deep iliac circumflex artery Inferior epigastric artery Iliolumbar artery Superior gluteal artery Obturator artery Femoral Medial femoral circumflex artery Lateral femoral circumflex artery Obturator artery Inferior gluteal artery Superior gluteal artery Iliolumbar artery Uterine artery Middle rectal artery Inferior rectal artery (internal pudendal) 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 • • • 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 1 st to the parametrial nodes --> obturator nodes --> pelvic nodes --> para-aortic • Uterine Cancer: – Drains 1 st 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 Sakralis Media İnternal iliak (hipogastrik) Common Iliac İliolumbar Lateral Sakral Superior Gluteal Inferior Gluteal Orta Hemoroidal Pudendal Uterin Inferior Vesika Umbilical Obturator Burnett Novack’s Gynecology 20

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 20

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 E 1 E 2

Asetat Kolesterol Sitokrom P 450 scc Progesteron Pregnanolon 17 OH Pregnanolon 17 -20 Desmolase 17 α OH ase 3 β OH SDH 17 α OH ase E 3 17 OH Progesteron 17 -20 Desmolase M O AR Androstenedion DHEA 17 β OH SDH ? Z A AT 17 β OH SDH E 1 17 β OH SDH AZ Androstenediol Testosteron O AR 5 α redüktase DHT T MA E 2

Gonadotropin Releasing Hormone (Gn. RH) • • Secreted by hypothalamus Pulsatile secretion is critical for activity Gn. RH secretion inhibited by estrogen Low levels of estrogen cause hypothalamus to release Gn. RH

Follicle-stimulating Hormone (FSH ) • • FSH hormone is secreted by anterior pituitary Turned on by Gn. RH 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 E 2 more than 200 pg /ml > 50 hours

A threshold of LH 14 -27 hours for full maturation of the oocyte to occur

The End