Female Reproductive

FEMALE REPRODUCTIVE

Primary Sex Organs

• Gonads (Ovaries)

– Gametes

•Ovum or eggs

• Chromosomes• 46 Chromosomes, 23 Pairs in somatic cells

– Diploid (2N)

• 23 chromosomes in gametes

• Haploid (1N)

Secondary/Accessory Organs

• Female

– Uterine Tubes

– Uterus

– Vagina

– External genitalia

– Mammary glands

28-4

• Internal genitalia

– Ovaries, uterine

tubes, uterus, and

vagina

• External genitalia

– Clitoris, labia minora,

and labia majora

• Primary sex organs

– Ovaries

• Secondary sex organs

– Other internal and

external genitalia

The Genitalia

Figure 28.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Uterine tube

Urinary bladder

Ovary

Uterus

Rectum

Pubic symphysis

Fimbriae

Anterior fornix

Cervix of uterus

Anus

Posterior fornix

Prepuce

Labium minus

Labium majus

Mons pubis

Urethra

Peritoneum

Clitoris

Round ligamentVesicouterine

pouchRectouterine

pouch

Vaginal rugae

Vaginal orifice

28-5

• Internal genitalia

– Ovaries, uterine

tubes, uterus, and

vagina

• External genitalia

– Clitoris, labia minora,

and labia majora

• Primary sex organs

– Ovaries

• Secondary sex organs

– Other internal and

external genitalia

The Genitalia

Figure 28.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Uterine tube

Urinary bladder

Ovary

Uterus

Rectum

Pubic symphysis

Fimbriae

Anterior fornix

Cervix of uterus

Anus

Posterior fornix

Prepuce

Labium minus

Labium majus

Mons pubis

Urethra

Peritoneum

Clitoris

Round ligamentVesicouterine

pouchRectouterine

pouch

Vaginal rugae

Vaginal orifice

External Genitalia

• Collectively called the vulva

• Labium majus

• Labium minus

• Clitoris

• Mons Pubis

Vagina

• Birth Canal

• Functions

– Discharge of menstrual fluid

– Receipt of penis and semen

– Birth of baby

• Hymen

• Vaginal rugae

Ovarian arteryOvarian vein

Ovary

MesometriumFimbriae

Endometrium

Myometrium

Cervix

Uterine

tube

Suspensory

ligament

Ovarian

ligament

Vagina

Ovaries

• On each side of uterus in pelvic cavity.

• Ovarian ligaments secure them to uterus.

• Mesometrium (parietal peritoneum) holds uterus, ovary, uterine tubes in position in peritoneal cavity

• Suspensory ligaments contains ovarian artery, vein and nerves; secure ovary to pelvic wall.

Inside the ovary:

Oocyte Suspensory ligament

and blood vessels

Mature

follicleSecondary

follicle

Primary

follicles

Primordial

follicles

Ovarian

ligament

Corpus

albicansCorpus

luteum

Fimbriae

of uterine

tube

Ovulated

oocyte

•Follicles nourish the developing oocyte and secrete mostly estrogen

• Ovarian follicles > each

contain an oocyte in

different states of

maturation.

• As they mature the follicles

are called:

– Primordial follicle >

Primary follicle >

Secondary follicle>

Mature (Graafian)follicle.

PrimaryFollicle

Primaryoocyte

Secondary oocyte

SecondaryFollicle

MatureFollicle

ovulationexpelled

contains

contains

Ovarian Follicles

▪ Primordial follicle:

• a primary oocyte surrounded by a single layer of follicular cells

▪ Primary follicle:

• a larger oocytes and still single layer of follicular cells

▪ Secondary follicles

• still larger oocytes and follicular cells now stratified (granulosa cells)

▪ Mature (graafian) follicles• become fluid filled cavity

(antrum) with oocyte pushed to one side

After the ovulation:

• After the ovulation, remnants of the

follicle is called Corpus luteum > a gland

like structure.

• Corpus luteum secretes estrogen &

progesterone until it degenerates into

corpus albicans.

Uterine (Fallopian) tubes

• 2 muscular tubes - extend from ovary to uterus.

– Distal ends expand to form infundibulum.

– ampulla – middle and longest part

– isthmus – narrower end toward uterus

• Fingerlike projections called fimbriae.

Ovary

BodyFundusIsthmusAmpullaInfundibulum

Fimbriae

EndometriumInternal os

Myometrium

Lateral fornix

Cervix

Cervical canal

External os

Uterine

tube

Vagina

Uterine (Fallopian) tubes

• Walls:

– Innermost mucous - lined with ciliated cells

– middle layer - smooth muscle

• Peristalsis & ciliary action transport oocyte or fertilized

ovum to uterus

– Outer layer – serous membrane

• Site of fertilization.

• Fimbriae sweep the egg towards uterine

tube.

Uterus

Thick-walled, pear-shaped muscular chamber opening into vagina

Three anatomical segments:1. Fundus: dome shaped superior part.

2. Body: central part.

3. Cervix: narrow inferior portion joining vagina.

– Openings of cervical canal• Internal os : opening into uterus

• external os: opening into vagina

The Uterus

fundus

BodyUterine cavityInternal osCervix

External osvagina

Uterine wall:

1. Perimetrium- outer serosal layer.

2. Myometrium- middle muscular layer.

➢Labor contractions to expel the fetus

• Endometrium- innermost-highly vascular epi cells –mucosal layer

Divided into two layers:1) Stratum functionalis :

➢closer to the cavity > shed during menstruation

& rebuilt again if no implantation occurs.

2) Stratum basalis:permanent layer> build the

functional layer after each menstruation.

Vagina (birth canal)

• Extends from the cervix to the exterior.

• Common pathway for menstrual flow & the birth of a baby and receives semen

• Very distensible.

• Outer adventitia, middle muscularis & inner mucosa

• Acidic pH, but it is neutralized by slightly alkaline semen.

Mammary glands

• Nonlactating breast consists mostly of adipose and collagenous tissue

• Modified sweat glands.

• Lies over pectoral muscle, surrounded by adipose tissue.

• Each breast> pigmented projection > nipple.

• Contain milk producing glands & ducts for

delivery.

Suspensory

ligamentLobules

Lobe

Adipose tissue

Nipple

Lactiferous sinus

Lactiferous duct

RibIntercostal musclesPectoralis minorPectoralis majorFascia

Lactating breast

• 15 to 20 lobes around the nipple

• Lactiferous duct drains each lobe

• Path of milk flow: glands > lactiferous ducts > lactiferous sinus > nipple > exterior.

• Hormones of pregnancy stimulate milk production.

• Lactation: production & ejection of milk.

Adipose tissue

Suspensory

ligaments

Lobe

Lobules

Areolar glands

Areola

Nipple

Lactiferous sinus

Lactiferous ducts

Milk & Colostrum

• Colostrum:

– thin secretion before milk is produced.

– similar to breast milk but contains 1/3 less

fat,

– nutrition for first 1 to 3 days after birth

• Milk: water, proteins, fat, sugar, salts,

lysozyme, and antibody.

• Milk production- stimulated by prolactin.

• Milk ejection is controlled by oxytocin

Oogenesis

• Formation & maturation of ovum in ovary.

• Starts in fetus, but not completed until after puberty.

• Meiosis I starts before birth.

• One secondary oocyte completes maturation every month.

• After ovulation > S. oocyte enters uterine tube.

• If sperms are present, fertilization may take place.

• Ovulation: discharge of S. oocyte from ovary into pelvic cavity – every month.

Primary oocyte

Secondary oocyte + polar body

Meiosis

(2n)

(n) (n)

OOGENESIS

If sperms are present in the fallopian tube:

Sperm (n) + S. oocyte (n)

Fertilization

Zygote (2n)

Female reproductive cycles:

1. Ovarian cycle

2. Uterine/Menstrual cycle

3. Hormonal cycle

Ovarian cycle:

• Associated with maturation of egg every

month.

• Duration 28 days.

• Ovulation occurs 14th day in a 28 day

cycle.

• FSH and LH and estrogen regulates it.

• Three main events:

– Follicular phase, ovulation, luteal phase

Ovarian Cycle

Follicular Phase & Ovulation• Follicular phase from the beginning of

menstruation until ovulation

– day 1 to day 14 of an average cycle

– FSH stimulates growth of follicles and to secrete estrogen

– Menstruation - during first 3 to 5 days of cycle

• Ovulation – the rupture of the mature follicle and the release of its egg - typically around day 14

• Estrogen stimulates a surge of LH by anterior pituitary

– LH induces completion of meiosis I & production of secondary oocyte and first polar body

• Ovulation

Endoscopic View of Ovulation

© Landrum B. Shettles, MD

Fimbriae

Oocyte

Stigma

Ovary

0.1 mm

Cumulus

oophorus

Infundibulum of

uterine tube

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Ovarian Cycle

Luteal (Postovulatory) Phase• Luteal phase - days 15 to day 28

– ovulated follicle becomes the corpus luteum

– LH stimulates and maintains the corpus luteum

• If no pregnancy

– Corpus luteum eventually shrinks and becomes corpus albicans

Menstrual cycle

• Shedding & rebuilding of endometrium each month.

• Controlled by ovarian hormones.

• Closely coordinated with ovarian cycle.

• If no implantation, then 14 days after ovulation functional layer of endometrium disintegrates.

• Discharge 50-150 ml of blood, tissue fluid, cells etc.

• Caused by a fall in estrogen & progesterone

• Menstruation lasts about 5 days

Secretion

Myometrium(a) Proliferative phase (b) Secretory phase (c) Menstrual phase

Endometrial

gland

Stratum

functionalis

Stratum

basalis

Menstrual Cycle

Menstrual Cycle

28-32

Figure 28.14b

Days 1 3 5 7 9 11 13 15 17 19 21 23 25 27 1

(b) Menstrual cycle

Menstrual phase Proliferative phase Secretory phase

Th

ickn

ess o

f en

do

metr

ium

Ov

ari

an

ho

rmo

ne s

ecre

tio

n

Estradiol

Premenstrual

phase

Progesterone

Menstrual

fluid

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Hormonal cycle

• All cycles are regulated by hormones.

• Estrogen & progesterone, FSH and LH

• Released in a cyclic pattern.

• basic hierarchy of hormonal control

– hypothalamus pituitary ovaries uterus

• Starts at puberty.

Fig. 28.14

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Days 1 3 5 7 9 13 15 17 19 21 23 25 27 1

Days 1 3 5 7 9 11 13 15 17 19 21 23 25 27 1

(b) Menstrual cycle

(a) Ovarian cycle

LH

Developing follicles

PrimarySecondary

Ovulation

Luteal phaseFollicular phase

Corpus luteum Involution

Menstrual phase Proliferative phase Secretory phase

Th

ickn

ess o

f en

do

metr

ium

Ov

ari

an

ho

rmo

ne s

ecre

tio

nO

vari

an

ev

en

tsG

on

ad

otr

op

in s

ecre

tio

n

Estradiol

Progesterone

FSH

New primordial

follicles

Corpus

albicans

Tertiary

11

Premenstrual

phase

Menstrual

fluid

8-celled stage4-celled stage

Zygote

OvulationFirst polar body

Ovary

Blastocyst

Cleavage

Zona pellucida

Blastomeres

Implanted

blastocyst

(6 days)

Morula

(72 hours)

2-celled stage

(30 hours)

Corpus

luteum

Maturing

follicle

Secondary

oocyte

Second polar

body

Eggpronucleus

Spermpronucleus

Fertilization

(0 hours)

Sperm

cell

Fertilization & Implantation