1 THE FEMALE REPRODUCTIVE SYSTEM Lois E Brenneman, MSN, ANP, FNP, C PDF
Preview 1 THE FEMALE REPRODUCTIVE SYSTEM Lois E Brenneman, MSN, ANP, FNP, C
THE FEMALE REPRODUCTIVESYSTEM Lois E Brenneman, MSN, ANP, FNP, C OVERVIEW - Female - Urinary and reproductive system are completely separate - Internal structures located in lower pelvis; inside bony pelvis; behind pubic bone - Male: combine urinary and reproductive system in the male EMBRYOLOGY - Gonads in both sexes are bipotential until 6th week of gestation - Embryonic gonads may be become either testes or ovaries - Male/female development begins at 7th week - Locus on Y-chromosome determines testicular development - Causes development into testes - Caused testicular-determiningfactor - Genetically female embryo: gonad develops into ovary - Ovary-determining genes theorized; have yet to be identified - Cortex of gonad accumulates cells that develop into ovarian follicles - Each follicle contains primary oocyte - External genitalia bipotential until 8th week of gestation - Genetic male embryo: dihydrotestosterone effects differentiation into male genitalia - Binds to androgen receptors in external genitalia - Dihydrotestosterone is metabolite of testosterone - Without dihydrotestosterone: genitalia develop into female structure - Will develop into female genitalia regardless of genotype (XX or XY) -Testicular feminization syndrome Genetic male (XY) which develops female genitalia due to inherited absence of testosterone receptors © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 1 EXTERNAL REPRODUCTIVE STRUCTURES Mons pubis: rounded skin-covered fat pad - anterior to symphysis pubis - Darker, coarser hair forming inverted triangle (base situated over mons) - Abundance of sebaceous glands Labia majora (singular: labium majus) - Analogous to male scrotum; forms two lips - Outermost structures of vulva extend from mons pubis to anus - Folds of skin and fat - After puberty deeper pigmentation and covered with coarse hair - Normally close over urethral opening and vaginal introitus Labia minora (singular: labium minus) - Situated between labia majora - Delicate cutaneous structure; smaller than labia majora - Skin, fat and some erectile tissue; usually hairless and pink - Extend at hood of clitoris to base of vagina - Sebaceous glands with odor-bearing secretions - Outline the vestibule (see below) Clitoris - Located below clitoral hood (prepuce) - joining of labia minora - Erectile organ - analogous to male penis - Engorges during sexual stimulation - Approximately 2 cm x 0.5 cm - Very vascular with extensive innervation Urethra - urinary meatus - External opening of internal urinary bladder - Posterior to clitoris - Lies within vestibule (see below) - Location of Skene’s Glands (see below) © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 2 Vestibule - almond shaped between lines of attachment of labia minora -Clitoris situated at superior angle -Fourchette is the inferior boundary - Dimensions: 4-5 cm long; 2 cm wide when labia separated - Covered with pink membranes; delicate stratified epithelium - Major structures opening into the vestibule - Urethral opening (anteriorly) -Vaginal opening (midportion) -Bartholin’s glands - 2 lateral secretory ducts (lubricating) Bean-shaped, mucus-secreting glands on either side of vaginal orifice Secretions increase during sexual excitement Frequent site of gonorrheal infection -Skene’s glands: tiny mucus secreting glands - Situated inside and just posterior to external urethral meatus - Lubricating functions - Acts in concert with urethral glands to keep meatus lubricated Introitus - Opening between the external and internal genitalia -Hymen: connective tissue membrane surrounds introitus - Determines size and shape of introitus - Normallyruptured during initial intercourse or other trauma - Intact hymen does not confirm virginity - Can stretch without tearing - Configuration may be circular, oval or sieve-like - Occasionally imperforate - occludes menstrual flow Perineal body - lies between fourchette and anus - Fibrous connective tissue - site of episiotomy - Insertion site of several peritoneal muscles © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 3 INTERNAL REPRODUCTIVE STRUCTURES LOCATED IN LOWER PELVIS Ovaries - female gonads STRUCTURE - Paired glandular organs; pinkish-white to gray - Size: 3-5 cm long; 1.5-3 cm wide - Situated in lateral pelvic wall on either side of uterus - Suspended in round ligament; not directly attached to oviducts -Fallopiantubes not directly connected to ovary (open to peritoneal cavity) - Abnormal implantation outside reproductive system can occur (rare) - Egg can transport from opposite tube - Layers of ovary - Medulla(inner layer): blood vessels, lymphatics, connective and nerve tissue - Cortex: (outer layer) FUNCTION Female gamete production - Birth: 400,000 primordial egg cells per ovary - Adolescence: 30,000 to 50,000 remain - No additional egg cells produced after birth (in contrast to male: sperm) Function is regulated by anterior pituitary Follicles: - Oocytes in sustained meiotic phase - surrounded by granulosa cells - Mature into ovum over next 30 years or disintegrate Ovulation: ovaries produce ovum in response to hormonal stimulation Fallopian tubes(oviducts) - functions totransport ovum and sperm Extend outward from each side of body of uterus Conduit between ovary and uterus - Facilitates transport of fertilized ovum - Passageway for drainage of tubal secretions Attach at upper uterus - 13 cm in length; 0.5-1.0 cm in width Narrow muscular tubes - lines with cilia Two (2) Layers; surrounded by layers of involuntary muscle (muscularis layer) - Inner - Outer serous layer: smooth layer (serosa) - part of visceral peritoneum © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 4 Structural sections of fallopian tubes Interstitial sections: lies within uterine wall Isthmususual site for tubal ligation Narrowest section; closest to uterus Opens into uterine cavity Thick muscular wall with narrow lumen Ampulla - thin walled - usual site of fertilization Longest and widest section - 2/3 of total length Widens progressively to wide distal opening (infundibulum) Thin walled, highly folded lining Infundibulum: fimbriated end; lies in close proximity to ovary Fimbriae: finger-like projections PHYSIOLOGY Cilia:hair-like projections which facilitate transport of fertilized ovum Muscularis layer: muscle contraction Fimbriae: bend closer to ovary during the peri-ovulation period Uterus: thick-walled muscular organ - pear-shaped Located between bladder and rectum Structure Fundus: portion above insertion of fallopian tubes Cervix: lower constricted portion (protrudes into vagina) Body of uterus: between fundus and cervix Uterine walls - tri-layered -Endometrium: inner layer of cavity - Continuous with lining of fallopian tubes and vagina - Superficial layer: sheds during menstruation -Basal layer: cells regenerate superficial layer between cycles -Ciliated cells: moves secretions out of cavity into vagina © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 5 -Myometrium: middle, muscle layer - Major portion of uterine wall - Continuous with myometrium of fallopian tubes and vagina - Extends into all supporting ligaments except broad ligament - Muscle contractions: menstrual fluid or products of conception -Dysmenorrhea: painful contractions during menses -Labor: severely painful obstetrical contractions - Expands over 4000 times during pregnancy/labor -Perimetrium: external peritoneal covering -serous - Outer serous covering; derived from abdominal peritoneum - Outer layer merges with peritoneum covering broad ligaments - Reflected over bladder wall anteriorly - vesicouterine pouch - Posteriorly extends to form cul-de-sac or pouch of Douglas Proximity to bladder results in urinary symptoms esp during pregnancy or with uterine infections Ligamentous support: four sets -Broad ligaments: run laterally from body of uterus to pelvic side walls - Support vagina - prevent prolapse -Round ligaments: from fundus laterally (below tubes) into each labium majus - Holds fundus forward. -Uterosacral ligaments: uterocervical junction to sacrum (supports cervix) - Uterovesical ligament (fold of peritoneum: over fundus to bladder) - Rectovesical ligament: fold of peritoneum: posterior surface of uterus and reflected on rectum -Cardinal: transverse cervical ligaments - Firmly joined to supravaginal area of cervix Impairment of ligaments (senility, childbirth trauma) results in various anomalies Uterine prolapse and other anatomic distortion Cystocele, rectocele Anatomic orientation of uterus within pelvis is variable Anteverted (most common) Antiflexed Retroverted Retroflexed Will present differently on bimanual exam esp with fundal palpation © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 6 Cervix: lower portion of the uterus Round cervix: neck of uterus - protrudes into vagina Firm structure which becomes soft and pliable during hormones of pregnancy Small, shiny and pink; firmer than corpus (connective tissue) Structure: connective tissue matrix of glands and muscle tissue Glands secrete mucus:consistency/quantity varies with menstrual cycle and pregnancy Nabothian cyst: obstructed ducts causing cysts on cervix Mucus changes in response to hormonal variations Vascular supply from uterine artery: can cause significant obstetrical blood loss Endocervix: lining of cervical canal (endocervical canal) Ectocervix: cervical portion extending outward from the external cervical os Cervical os:opening of cervix forming pathway between vagina and uterus External os: vaginal opening Uterine os: uterine opening Endocervical canal: space between two openings - 2 to 2.5 cm - Line by columnar epithelium - Sampled during routine pap smear - Columnar epithelium secretions form mucus plug after conception - Portal for menstrual discharge and insemination Os varies with parity and stage of life Nulliparity: round os Parous: slit-like, irregular Menopausal: small, tight (sometimes stenotic) Epithelium 2 types: squamous epithelium and columnar epithelium Squamous epithelium: smooth shiny and pink - four layers Basal layer: lies within basement membrane, 1-2 cell layers Parabasal layer: 3-4 cell layers Intermediate layer: thicker than basal or parabasal Superficial layer: mature cells; continuously shed; thickest layer Columnar epithelium Dark red and granular; secretes mucus Lines endocervix © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 7 Squamocolumnar junction - SCJ - Boundary between squamous and columnar epithilium - Boundary migrates over time - change due to squamous metaplasia Adolescents: junction visible on external cervix Involutes into canal over time Menopause: extends up canal with decreasing estrogen levels -Eversion, ectropion, ectomy: where visible on ectocervix Granular, red - function of columnar epithelial component Well-circumscribed area (cervical ectopy) Sometimes erroneously called “erosion” Transformation zone - results from squamous metaplasia Critical to sample this zone during collecting pap Region is particularly susceptible to dysplasia Squamous metaplasia:transformation of columnar epithelium into squamous epithelium - Occurs as columnar changed to squamousepithelium - Change occurs naturally over time in response to increasing estrogen levels - SCJ found on the ectocervix in adolescents or young nulliparous - Increasing estrogen levels (acid environment ) cause metaplasia with maturity - SCJ found at os or further inside canal on mature women esp s/p childbirth - SCJ can be high in endocervical canal on menopausal women - Area of metaplasia called endocervical cells - Critical to sample this area during routine paps - Metaplastic region most susceptible to neoplasia © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 8 Vagina:fibromuscular tube connecting internal and external organs - Approximately 9 cm long; normally pinkish-red - Free of sensory nerve fibers - Located behind urinary bladder and urethra; anterior to rectum - Cervix protrudes into upper end -Fornices: recesses formed by protrusion of cervix - Anterior fornix, posterior fornix - Thin-walled allows for palpation of ovaries and uterus during bimanual exam - May pool semen after ejaculation facilitating intermittent release into os - Functions - Discharge route for menses and other secretions - Organ of sexual reproduction - receptacle for penis during intercourse - Birth canal with dilated cervix to expel fetus - Conduit for sperm to travel toward ovum - Structure - lined with squamous epithelium from cervix to vestibule - Two longitudinal folds - Transverse folds - rugae - Normally moist;very distensible: stretch/contract with intercourse or delivery - No mucus secreting glands: lubricated by cervical and glandular secretions - Normal physiology - pH 3.8 to 4.2 - bacteriostatic - Responsive to ovarian hormone levels - Colonized by lactobacilli (Doderlein’s bacilli) - normal vaginal flora -Bacterial vaginosis results when normal flora are disrupted EFFECTS OF ESTROGEN STIMULATION - Proliferation and maturation of mucosa - Thickened mucosa and increased epithelial glycogen - Glycogen fermented to lactic acid by lactobacilli resulting in acid pH - Menopausal ovarian failure results in changes from low estrogen levels - Urogenital atrophy - Thinning, flattening and friability of vulva - Loss of vaginal rugae, shortening of canal - atrophic vaginitis -Dyspareunia - atrophic vaginitis -Maturation Index: estimation of estrogen level - Examination of cellular structure and configuration of epithelium - Cytological exam of vaginal scrapings - Determines rate ratio of cell types - Parabasal (least mature) - Intermediate - Superficial (most mature) -Index varies with stage of life 0-40-60 during reproductive years 30-40-30 with perimenopause - Decreasing estrogen levels - Shift to left 75-20-0 during postmenopausal period © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 9 VAGINAL ECOLOGY - Minimal innervation: symptoms of infection evident only when discharge irritates vulva -Estrogenized epithelium well supplied with glycogen (within epithelial cells) Glycogen-rich epithelial cells rises with menarche Menopause results in declining levels of estrogen and associated glycogen - Normal flora - lactobacilli - metabolize glycogen - Pleomorphic, gram-positive aerobic or facultative anaerobic - Dominate normal flora - 96% in healthy woman - Slightly mobile straight rods with variable length -Maintain acid pH (3.8-4.2) of vaginal discharge via producing lactic acid - Acid environment and released peroxide inhibits pathogenic anaerobes - Acid pH inhibits bacterial adherence to epithelial cells - Most vaginal organisms exist symbiotically within the acid environment -Bacterial vaginosis results when normal flora balance is upset - Results from factors which decrease lactobacilli thus decrease acidity - Overgrowth of pathogens normally present in small amounts - Progesterone results in shedding of glycogen-rich cells into vaginal pool MENSTRUAL CYCLE Cyclical bleeding with shedding of endometrial lining during reproductive years Menarche: first menstrual bleed Menopause: last menstrual bleed Anovulatory cycles: bleeding without antecedent ovulation - often results in DUB * Cycle induces changes in other organs: breasts, uterus, skin, ovaries, sometimes affect * Dysfunctional uterine bleeding HORMONAL CONTROL Hypothalamic-Pituitary Hormones GnRH from hypothalamus stimulates anterior pituitary Anterior pituitary gland secretes FSH and LH (also secretes prolactin stimulates lactation) © 2001 Lois E. Brenneman, MSN, CS, ANP, FNP - all rights reserved www.npceu.com 10
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