28 the female reproductive system p a r t b. female reproductive anatomy ovaries are the primary...
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The Female Reproductive SystemThe Female Reproductive System
P A R T B
Female Reproductive AnatomyFemale Reproductive Anatomy
Ovaries are the primary female reproductive Ovaries are the primary female reproductive organsorgans Make female gametes (ova)Make female gametes (ova) Secrete female sex hormones (estrogen and Secrete female sex hormones (estrogen and
progesterone)progesterone) Accessory ducts include uterine tubes, Accessory ducts include uterine tubes,
uterus, and vaginauterus, and vagina Internal genitalia – ovaries and the internal Internal genitalia – ovaries and the internal
ductsducts External genitalia – external sex organsExternal genitalia – external sex organs
Female Reproductive AnatomyFemale Reproductive Anatomy
Figure 27.11
The OvariesThe Ovaries
Paired organs on each side of the uterus Paired organs on each side of the uterus held in place by several ligamentsheld in place by several ligaments Ovarian – anchors the ovary medially to the Ovarian – anchors the ovary medially to the
uterusuterus Suspensory – anchors the ovary laterally to Suspensory – anchors the ovary laterally to
the pelvic wallthe pelvic wall Mesovarium – suspends the ovary in between Mesovarium – suspends the ovary in between
Broad ligament – contains the suspensory Broad ligament – contains the suspensory ligament and the mesovariumligament and the mesovarium
The OvariesThe Ovaries
Figure 27.14a
OvariesOvaries
Blood supply – ovarian arteries and the Blood supply – ovarian arteries and the ovarian branch of the uterine arteryovarian branch of the uterine artery
They are surrounded by a fibrous tunica They are surrounded by a fibrous tunica albuginea, which is covered by a layer of albuginea, which is covered by a layer of epithelial cells called the germinal epithelial cells called the germinal epitheliumepithelium
Embedded in the ovary cortex are ovarian Embedded in the ovary cortex are ovarian folliclesfollicles
OvariesOvaries
Each follicle consists of an immature egg Each follicle consists of an immature egg called an oocytecalled an oocyte
Cells around the oocyte are called:Cells around the oocyte are called: Follicle cells (one cell layer thick) Follicle cells (one cell layer thick) Granulosa cells (when more than one layer is Granulosa cells (when more than one layer is
present)present)
OvariesOvaries
Primordial follicle – one layer of Primordial follicle – one layer of squamouslike follicle cells surrounds the squamouslike follicle cells surrounds the oocyteoocyte
Primary follicle – two or more layers of Primary follicle – two or more layers of cuboidal granulosa cells enclose the cuboidal granulosa cells enclose the oocyteoocyte
Secondary follicle – has a fluid-filled space Secondary follicle – has a fluid-filled space between granulosa cells that coalesces to between granulosa cells that coalesces to form a central antrumform a central antrum
OvariesOvaries
Graafian follicle – secondary follicle at its Graafian follicle – secondary follicle at its most mature stage that bulges from the most mature stage that bulges from the surface of the ovarysurface of the ovary
Ovulation – ejection of the oocyte from the Ovulation – ejection of the oocyte from the ripening follicleripening follicle
Corpus luteum – ruptured follicle after Corpus luteum – ruptured follicle after ovulationovulation
OvariesOvaries
Figure 27.12
Uterine Tubes (Fallopian Tubes) Uterine Tubes (Fallopian Tubes) and Oviductsand Oviducts
Receive the ovulated oocyte and provide a Receive the ovulated oocyte and provide a site for fertilizationsite for fertilization
Empty into the superolateral region of the Empty into the superolateral region of the uterus via the isthmusuterus via the isthmus
Expand distally around the ovary forming Expand distally around the ovary forming the ampullathe ampulla
The ampulla ends in the funnel-shaped, The ampulla ends in the funnel-shaped, ciliated infundibulum containing fingerlike ciliated infundibulum containing fingerlike projections called fimbriaeprojections called fimbriae
Uterine TubesUterine Tubes
The uterine tubes have no contact with the The uterine tubes have no contact with the ovaries and the ovulated oocyte is cast ovaries and the ovulated oocyte is cast into the peritoneal cavityinto the peritoneal cavity
Beating cilia on the fimbriae create Beating cilia on the fimbriae create currents to carry the oocyte into the currents to carry the oocyte into the uterine tubeuterine tube
The oocyte is carried toward the uterus by The oocyte is carried toward the uterus by peristalsis and ciliary actionperistalsis and ciliary action
Uterine TubesUterine Tubes
Nonciliated cells keep the oocyte and the Nonciliated cells keep the oocyte and the sperm nourished and moistsperm nourished and moist
Mesosalpinx – visceral peritoneum that Mesosalpinx – visceral peritoneum that supports the uterine tubessupports the uterine tubes
UterusUterus
Hollow, thick-walled organ located in the Hollow, thick-walled organ located in the pelvis anterior to the rectum and pelvis anterior to the rectum and posterosuperior to the bladderposterosuperior to the bladder
Body – major portion of the uterusBody – major portion of the uterus Fundus – rounded region superior to the Fundus – rounded region superior to the
entrance of the uterine tubesentrance of the uterine tubes Isthmus – narrowed region between the Isthmus – narrowed region between the
body and cervixbody and cervix
UterusUterus
Cervix – narrow neck which projects into Cervix – narrow neck which projects into the vagina inferiorlythe vagina inferiorly
Cervical canal – cavity of the cervix that Cervical canal – cavity of the cervix that communicates with:communicates with: The vagina via the external osThe vagina via the external os The uterine body via the internal osThe uterine body via the internal os
Cervical glands secrete mucus that covers Cervical glands secrete mucus that covers the external os and blocks sperm entry the external os and blocks sperm entry except during midcycleexcept during midcycle
Supports of the UterusSupports of the Uterus
Mesometrium – portion of the broad Mesometrium – portion of the broad ligament that supports the uterus laterallyligament that supports the uterus laterally
Lateral cervical ligaments – extend from Lateral cervical ligaments – extend from the cervix and superior part of the vagina the cervix and superior part of the vagina to the lateral walls of the pelvisto the lateral walls of the pelvis
Uterosacral ligaments – paired ligaments Uterosacral ligaments – paired ligaments that secure the uterus to the sacrumthat secure the uterus to the sacrum
Round ligaments – bind the anterior wall to Round ligaments – bind the anterior wall to the labia majorathe labia majora
Peritoneal PouchesPeritoneal Pouches
Several cul-de-sacs of peritoneum exist Several cul-de-sacs of peritoneum exist around the uterusaround the uterus Vesicouterine pouch – lies between the Vesicouterine pouch – lies between the
bladder and the uterusbladder and the uterus Rectouterine pouch – lies between the rectum Rectouterine pouch – lies between the rectum
and the uterusand the uterus
Uterine WallUterine Wall
Composed of three layersComposed of three layers Perimetrium – outermost serous layer; the Perimetrium – outermost serous layer; the
visceral peritoneumvisceral peritoneum Myometrium – middle layer; interlacing layers Myometrium – middle layer; interlacing layers
of smooth muscle of smooth muscle Endometrium – mucosal lining of the uterine Endometrium – mucosal lining of the uterine
cavitycavity
Uterine WallUterine Wall
Figure 27.15b
EndometriumEndometrium Has numerous uterine glands that change Has numerous uterine glands that change
in length as the endometrial thickness in length as the endometrial thickness changeschanges
Stratum functionalis:Stratum functionalis: Undergoes cyclic changes in response to Undergoes cyclic changes in response to
ovarian hormonesovarian hormones Is shed during menstruationIs shed during menstruation
Stratum basalis:Stratum basalis: Forms a new functionalis after menstruation Forms a new functionalis after menstruation
endsends Does not respond to ovarian hormonesDoes not respond to ovarian hormones
Uterine Vascular SupplyUterine Vascular Supply
Uterine arteries – arise from the internal Uterine arteries – arise from the internal iliacs, ascend the sides of the uterus and iliacs, ascend the sides of the uterus and send branches into the uterine wallsend branches into the uterine wall
Arcuate arteries – branches of the uterine Arcuate arteries – branches of the uterine arteries in the myometrium that give rise to arteries in the myometrium that give rise to radial branchesradial branches
Radial branches – descend into the Radial branches – descend into the endometrium and give off:endometrium and give off: Spiral arteries to the stratum functionalisSpiral arteries to the stratum functionalis Straight arteries to the stratum basalisStraight arteries to the stratum basalis
Uterine Vascular SupplyUterine Vascular Supply
Degeneration and regeneration of spiral Degeneration and regeneration of spiral arteries causes the functionalis to shed arteries causes the functionalis to shed during menstruationduring menstruation
Veins of the endometrium are thin-walled Veins of the endometrium are thin-walled with occasional sinusoidal enlargementswith occasional sinusoidal enlargements
VaginaVagina
Thin-walled tube lying between the Thin-walled tube lying between the bladder and the rectum, extending from bladder and the rectum, extending from the cervix to the exterior of the bodythe cervix to the exterior of the body
The urethra is embedded in the anterior The urethra is embedded in the anterior wallwall
Provides a passageway for birth, Provides a passageway for birth, menstrual flow, and is the organ of menstrual flow, and is the organ of copulationcopulation
VaginaVagina
Wall consists of three coats: fibroelastic Wall consists of three coats: fibroelastic adventitia, smooth muscle muscularis, and adventitia, smooth muscle muscularis, and a stratified squamous mucosa a stratified squamous mucosa
Mucosa near the vaginal orifice forms an Mucosa near the vaginal orifice forms an incomplete partition called the hymenincomplete partition called the hymen
Vaginal fornix – upper end of the vagina Vaginal fornix – upper end of the vagina surrounding the cervixsurrounding the cervix
VaginaVagina
Figure 27.16a
Female External Genitalia: Female External Genitalia: DeepDeep
Figure 27.16b
External Genitalia: Vulva External Genitalia: Vulva (Pudendum)(Pudendum)
Lies external to the vagina and includes the Lies external to the vagina and includes the mons pubis, labia, clitoris, and vestibular mons pubis, labia, clitoris, and vestibular structuresstructures
Mons pubis – round, fatty area overlying the Mons pubis – round, fatty area overlying the pubic symphysis pubic symphysis
Labia majora – elongated, hair-covered, fatty Labia majora – elongated, hair-covered, fatty skin folds homologous to the male scrotumskin folds homologous to the male scrotum
Labia minora – hair-free skin folds lying within Labia minora – hair-free skin folds lying within the labia majora; homologous to the ventral the labia majora; homologous to the ventral penispenis
External Genitalia: Vulva External Genitalia: Vulva (Pudendum)(Pudendum)
Greater vestibular glandsGreater vestibular glands Pea-size glands flanking the vagina Pea-size glands flanking the vagina Homologous to the bulbourethral glandsHomologous to the bulbourethral glands Keep the vestibule moist and lubricatedKeep the vestibule moist and lubricated
External Genitalia: Vulva External Genitalia: Vulva (Pudendum)(Pudendum)
Clitoris (homologous to the penis)Clitoris (homologous to the penis) Erectile tissue hooded by the prepuceErectile tissue hooded by the prepuce The exposed portion is called the glansThe exposed portion is called the glans
PerineumPerineum Diamond-shaped region between the pubic Diamond-shaped region between the pubic
arch and coccyx arch and coccyx Bordered by the ischial tuberosities laterallyBordered by the ischial tuberosities laterally
Mammary GlandsMammary Glands
Modified sweat glands consisting of 15-25 lobes Modified sweat glands consisting of 15-25 lobes that radiate around and open at the nipple that radiate around and open at the nipple
Areola – pigmented skin surrounding the nippleAreola – pigmented skin surrounding the nipple Suspensory ligaments attach the breast to Suspensory ligaments attach the breast to
underlying muscle fasciaunderlying muscle fascia Lobes contain glandular alveoli that produce milk Lobes contain glandular alveoli that produce milk
in lactating womenin lactating women Compound alveolar glands pass milk to Compound alveolar glands pass milk to
lactiferous ducts, which open to the outsidelactiferous ducts, which open to the outside
Structure of Lactating Mammary Structure of Lactating Mammary GlandsGlands
Figure 27.17
Breast CancerBreast Cancer Usually arises from the epithelial cells of the Usually arises from the epithelial cells of the
ductsducts Risk factors include:Risk factors include:
Early onset of menses or late menopauseEarly onset of menses or late menopause No pregnancies or the first pregnancy late in lifeNo pregnancies or the first pregnancy late in life Previous history of breast cancer or family history of Previous history of breast cancer or family history of
breast cancerbreast cancer Hereditary factors including mutations to the genes Hereditary factors including mutations to the genes
BRCA1 and BRCA2BRCA1 and BRCA2
70% of women with breast cancer have no 70% of women with breast cancer have no known risk factorsknown risk factors
Breast Cancer: Detection and Breast Cancer: Detection and TreatmentTreatment
Early detection is by self-examination and Early detection is by self-examination and mammographymammography
Treatment depends upon the Treatment depends upon the characteristics of the lesioncharacteristics of the lesion
Radiation, chemotherapy, and surgery Radiation, chemotherapy, and surgery followed by irradiation and chemotherapyfollowed by irradiation and chemotherapy
Today, lumpectomy is the surgery used Today, lumpectomy is the surgery used rather than radical mastectomy rather than radical mastectomy
OogenesisOogenesis
Production of female sex cells by meiosisProduction of female sex cells by meiosis In the fetal period, oogonia (2In the fetal period, oogonia (2nn ovarian ovarian
stem cells) multiply by mitosis and store stem cells) multiply by mitosis and store nutrientsnutrients
Primordial follicles appear as oogonia are Primordial follicles appear as oogonia are transformed into primary oocytestransformed into primary oocytes
Primary oocytes begin meiosis but stall in Primary oocytes begin meiosis but stall in prophase Iprophase I
Oogenesis: PubertyOogenesis: Puberty At puberty, one activated primary oocyte At puberty, one activated primary oocyte
produces two haploid cells produces two haploid cells The first polar bodyThe first polar body The secondary oocyteThe secondary oocyte
The secondary oocyte arrests in The secondary oocyte arrests in metaphase II and is ovulatedmetaphase II and is ovulated
If penetrated by sperm the second oocyte If penetrated by sperm the second oocyte completes meiosis II, yielding:completes meiosis II, yielding: One large ovum (the functional gamete)One large ovum (the functional gamete) A tiny second polar bodyA tiny second polar body
Figure 27.19
Ovarian CycleOvarian Cycle
Monthly series of events associated with Monthly series of events associated with the maturation of an eggthe maturation of an egg
Follicular phase – period of follicle growth Follicular phase – period of follicle growth (days 1–14)(days 1–14)
Luteal phase – period of corpus luteum Luteal phase – period of corpus luteum activity (days 14–28)activity (days 14–28)
Ovulation occurs midcycleOvulation occurs midcycle
Follicular PhaseFollicular Phase
The primordial follicle, directed by the The primordial follicle, directed by the oocyte, becomes a primary follicleoocyte, becomes a primary follicle
Primary follicle becomes a secondary Primary follicle becomes a secondary follicle follicle The theca folliculi and granulosa cells The theca folliculi and granulosa cells
cooperate to produce estrogenscooperate to produce estrogens The zona pellucida forms around the oocyteThe zona pellucida forms around the oocyte The antrum is formedThe antrum is formed
Follicular PhaseFollicular Phase
The secondary follicle becomes a The secondary follicle becomes a vesicular folliclevesicular follicle The antrum expands and isolates the oocyte The antrum expands and isolates the oocyte
and the corona radiataand the corona radiata The full size follicle (vesicular follicle) bulges The full size follicle (vesicular follicle) bulges
from the external surface of the ovaryfrom the external surface of the ovary The primary oocyte completes meiosis I, and The primary oocyte completes meiosis I, and
the stage is set for ovulationthe stage is set for ovulation
Ovarian CycleOvarian Cycle
Figure 27.20
OvulationOvulation
Ovulation occurs when the ovary wall Ovulation occurs when the ovary wall ruptures and expels the secondary oocyteruptures and expels the secondary oocyte
Mittelschmerz – a twinge of pain Mittelschmerz – a twinge of pain sometimes felt at ovulationsometimes felt at ovulation
1-2% of ovulations release more than one 1-2% of ovulations release more than one secondary oocyte, which if fertilized, secondary oocyte, which if fertilized, results in fraternal twins results in fraternal twins
Luteal PhaseLuteal Phase After ovulation, the ruptured follicle collapses, After ovulation, the ruptured follicle collapses,
granulosa cells enlarge, and along with internal granulosa cells enlarge, and along with internal thecal cells, form the corpus luteumthecal cells, form the corpus luteum
The corpus luteum secretes progesterone and The corpus luteum secretes progesterone and estrogenestrogen
If pregnancy does not occur, the corpus luteum If pregnancy does not occur, the corpus luteum degenerates in 10 days, leaving a scar (corpus degenerates in 10 days, leaving a scar (corpus albicans)albicans)
If pregnancy does occur, the corpus luteum If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over produces hormones until the placenta takes over that role (at about 3 months)that role (at about 3 months)
Establishing the Ovarian CycleEstablishing the Ovarian Cycle
During childhood, ovaries grow and During childhood, ovaries grow and secrete small amounts of estrogens that secrete small amounts of estrogens that inhibit the hypothalamic release of GnRHinhibit the hypothalamic release of GnRH
As puberty nears, GnRH is released; FSH As puberty nears, GnRH is released; FSH and LH are released by the pituitary, which and LH are released by the pituitary, which act on the ovariesact on the ovaries
These events continue until an adult cyclic These events continue until an adult cyclic pattern is achieved and menarche occurspattern is achieved and menarche occurs