Anatomy of Female Reproductive Tract
R,D FIROUZABADI External Genital Organs
mons pubis (Sp ,Distribution Of Hair)
labia majora (Sp_perineum,round lig, scrotom,without mus,8,-2.5,1-2.5 mucous labia minora – prepuce (clitoral hood) – frenulum of the labia minora = fourchette – w/o hair follicle ,nervous corposcle,variable in size,shape, 2 flat, red ,urethral fold vestibule of the vagina (6 orifice)lab minor, fourchette,clitoris – external urethral orifice paraurethral glands (Skene’s glands) [prostate] Bartholin's gland Clitoris: Glans,corpus,crura(inf ischiopubic Pubic arch body),nerve,squamus
– vaginal orifice
hymen – greater vestibular glands
Bartholin’s glands [bulbourethral glands] arterial supply – two external pudendal arteries – one internal pudendal artery venous drainage: internal pudendal veins
PELVIC DIAPHRAGM levator ani ,coccygeus
UROGENITAL DIAPHRAGM deep trns ,cons urth,int,ext
Pelvic Viscera urinary organs – ureters
pass medial to origin of uterine artery and continues to level of ischial spine, where is crossed superiorly by the uterine artery. Then passes close to lateral portion of vaginal fornix and enters posterosuperior angle of bladder – urinary bladder
hollow viscus with strong muscular walls
trigone of bladder – urethra - about 4 cm long, anterior to vagina rectum – Ligaments
round ligament of uterus - attaches anterior- inferiorly to uterotubal junctions
ligament of ovary - attached to uterus, posterior- inferior to uterotubal junctions
broad ligament - encloses body of uterus, freely moveable
transverse cervical ligaments - extend from cervix and lateral parts of vaginal fornix to lateral walls of pelvis
uterosacral ligaments - pass superiorly and slightly posteriorly from sides of cervix to middle of sacrum, can be palpated through rectum as pass posteriorly at sides of rectum. Hold cervix in normal relationship to sacrum. Broad Ligament
Contains between its layers the fallopian tube; the ovary and the round ligament; the uterine and ovarian blood vessels, nerves, lymphatics, and fibromuscular tissue; and a portion of the ureter as it passes lateral to the uterosacral ligaments over the lateral angles of the vagina and into the base of the bladder
Internal Genital Organs
vagina – fornix – rectouterine pouch (pouch of Douglas) – sphincters of vagina
pubovaginalis muscle
urogenital diaphragm
bulbospongiosus muscle – lymphatic drainage
superior part into internal and external iliac lymph nodes
middle part into the internal iliac lymph nodes
vestibule into superficial inguinal lymph nodes
Uterus
– 7-8 cm long, 5-7 cm wide, 2-3 cm thick – projects superior-anteriorly over urinary bladder – two major parts
body (superior 2/3s) – fundus
cervix (inferior 1/3) – internal os – external os – anterior lip – posterior lip – lined with columnar, mucus-secreting epithelium
isthmus = a transitional zone between body
– wall of uterus consists of 3 layers:
Perimetrium/serosa - outer serous coat, peritoneum supported by thin layer of connective tissue
myometrium - 12-15 mm smooth muscle, main branches of blood vessels and nerves of uterus are in this layer
endometrium - inner mucous coat
uterine tubes 10-12 cm long, 1 cm diameter – 4 parts – extend laterally from cornua of uterus
infundibulum – distal end – abdominal ostium, about 2 mm in diameter – 20-30 fimbriae – ovarian fimbria is attached to ovary
ampulla – tortuous part – widest and longest part, over 1/2 its length – fertilization occurs here – Most common site for ectopic OVARY
Almond shape Syn & sec st hor Dev &extrusion of ovaWALDEYER FOSSA UT-OVA LIG CORTEX (AGE),MEDULLA(ART,) SYM(OVA PLX), PARASYMP Ovary
By the fifth week of embryonic life, germ cells have formed the ovary Maximum # of eggs the ovary is able to produce is at 20 weeks of gestation… 6- 7 million! 1-2 million at birth 300,000 at the onset of puberty! Ovary
The functional unit is the FOLLICLE Oocyte (frozen in the first stage of meiosis) surrounded by granulosa cells & adjacent stromal cells…Theca cells. FSH will target the granulosa cells LH will target the thecal & stromal cells Ovary, cont’d
As the follicle matures, Antrum develops around the oocyte A bunch of follicles will develop around day 7 of cycle…a dominant follicle will win!
Ovary cont’d
Rising estrogen levels from the maturing follicle itself will ‘prime’ the follicle for the LH surge. When estrogen levels reach 200pg/ml or greater for longer than 48 hours, the LH surge occurs The granulosa cells become luteinized just prior to ovulation & begin to produce progesterone Progesterone rise is responsible for...
Facilitates the positive feedback action of estradiol in initiating the LH surge – LH surge occurs about 36 hours prior to ovulation Responsible for the FSH peak
Ovary
An avascular area will develop on the wall of the follicle & with the help of proteolytic enzymes ovulation occurs. The oocyte is picked up by the fimbriae of the tube If not met by a sperm will degenerate in 12-24 hours! Ovary
After ovulation, luteinization will transform the ruptured follicle into a corpus luteum which produces estrogen & progesterone for the next 12- 16 days If not aided by secretion of hCG, the corpus luteum will become the corpus albicans
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 Ut: common iliac ,Periaortic nodes. Lymph, cont’d
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 NERVES
SYMPATHIC : aortic plx ,int iliac,franken huser(ut,bllader,sup vagina) PARASYMPATHIC CEREBROSPINAL T11,T12,sensory nerves from ut transmit painful stimuli of ut cont to cent sys.sens nev cx,upper vag s2,3,4 lower through the pudendal n Innervation – ilioinguinal nerve – genital branch of the genitofemoral nerve – perineal branch of the femoral cutaneous nerve of thigh – perineal nerve isthmus
short 2.5 cm, narrow, thick-walled part of tube that enters the uterine cornu
uterine part – short segment that passes through thick myometrium of uterus – uterine ostium (smaller than abdominal ostium) Blood supply
Ovarian Art Uterin Art Ut vein
Acrcuate vein Ut vein
Hypogastric vein
common iliac Ovarian vein
Sup of ut, ovary, Sup of large lig
Pampiniform plexus
Ovarian vein
Ovaries oval, almond-shaped, 3 cm long, 1.5 cm wide, 1 cm thick – ligaments
superior (tubal) end of ovary is connected to lateral wall of pelvis by suspensory ligament of the ovary – contains ovarian vessels and nerves
ligament of ovary - connects inferior (uterine) end of ovary to lateral angle of uterus – surface of ovary is not covered by peritoneum
Female Bony Pelvis
wider, shallower, and has larger superior and inferior pelvic apertures than male pelvis hip bones farther apart ischial tuberosities are farther apart because of wider pubic arch sacrum is less curved, which increases the size of the inferior pelvic aperture and the diameter of the birth canal obturator foramina is oval Types of Bony Pelvis
anthropoid = AP diameter > transverse diameter – 23% females platypelloid – uncommon android = wide transverse diameter, posterior part of aperture is narrow – 32% females gynecoid = most spacious obstetrically – 43% females
Superior Pelvic Aperture
AP diameter = measurement from the midpoint of the superior border of pubic symphysis to the midpoint of sacral promontory transverse diameter = greatest width, measured from linea terminalis on one side to this line on opposite side oblique diameter = measurement from one iliopubic eminence to the opposite sacroiliac joint midplane diameter = interspinous diameter or distance between ischial spines and cannot be measured. Is estimated by palpating the scarospinous ligament through the vagina. The length of this ligament = about half the midplane diameter. determine prominence of ischial spines – < 9.5 cm may prevent passage of fetus Physiology
Hypothalamus Anterior Pituitary Ovary Endometrium & outflow tract Hypothalamus Release of GnRH (gonadotropin- releasing hormone), also called LHRH, into the pituitary portal circulation via the pituitary stalk The menstrual cycle does not ‘begin’ here!! All are inter-related ! Hypothalamus
What triggers the release of GnRH? – Unclear but in animal studies dopamine is inhibitory & norepinephrine is stimulatory – For normal gonadotropin release, GnRH must be released in pulses. The pulse frequency & amplitude are critical for normal menses – Decrease in pulse frequency will decrease LH release & increase FSH – Increase pulse frequency will increase LH & decrease FSH Anterior Pituitary
Gonadotrophs respond to the GnRH by producing FSH (follicle stimulating hormone) & LH (Luteinizing hormone) into the general circulation Release at this level is also controlled by circulating levels of estrogen & progesterone (gonadal steroids)…positive & negative feedback Anterior Pituitary
Stores & releases FSH & LH Day 1-7, follicular phase: estrogen from the ovary will stimulate storage of FSH & LH(in the pituitary)…also inhibits secretion Later in follicular phase with increasing estrogen levels (enlarging follicle) effect on gonadotrophs changes to stimulatory allowing for a secretion of LH which triggers ovulation
Under the influence of LH, the follicle begins to secrete progesterone shortly before ovulation Low level of progesterone will induce the FSH surge that occurs immediately prior to ovulation FSH Surge
– matures the oocyte (stimulates gametogenesis – produces proteolytic enzymes needed for follicle rupture – Increases the # of LH receptors(ovarian) required for optimal progesterone production in the luteal phase LH surge – increase in intrafollicular proteolytic enzymes that destroy the basement membrane and allow follicular rupture – luteinization of the granulosa cells and theca, resulting in increased progesterone production – resumption of meiosis in the oocyte, thus preparing it for fertilization – an influx of blood vessels into the follicle, preparing it to become a corpus luteum.
After ovulation, the secretion of estrogen & progesterone in high concentrations from the corpus luteum inhibits both gonadotrophs & GnRH As the corpus luteum dies off the hormone levels subside & FSH resumes the cycle Androgens
Androstenedione & testosterone are also secreted & can alter the ability of the ovary to respond to FSH & LH…may create atretic follicles early on TWO CELL THEORY
…of ovarian steroidogenesis Theca cells produce androgens under the influence of LH Granulosa cells convert the androgens to estrogen under the influence of FSH Endometrium
Contains receptors for both estradiol & progesterone Estradiol causes the proliferation, steady increase in thickness of lining When the corpus luteum starts producing progesterone; the proliferative effect of estradiol is neutralized & endometrial growth ceases
Endometrium
The lining now becomes SECRETORY with the endometrial vessels coiling & preparing to shed If no baby… corpus luteum stops producing estrogen & progesterone. This withdrawal of steroid support from the endometrium causes endometrial breakdown Why don’t women bleed to death every month??
Vascular spasm Thrombosis Resumption of endometrial proliferation under the influence of unopposed estrogen Myometrial ischemia - dysmenorrhea