The Female Reproductive System

Lab # 11

The Female Reproductive System

Main Reproductive Organs or Gonads Duct System Accessory Glands

and Organs External Genitalia

OvariesUterine or Fallopian tubesUterus

Vagina

Bartolini’s or greater vestibular glands

Paraurethral glands

ClitorisLabia minoraLabia mayora

The Female Reproductive SystemOvaryUterine or

Fallopian tube

Uterus

Vagina

Bartolini’s or greater vestibular gland

Paraurethral glands

Fornix

Clitoris

Tunica albuginea

It is where gametes are produced.

Cortex

MedullaIt is occupied by major arteries and veins.

The egg develop in their own fluid-filled follicles

Follicle bursting and releasing the egg (ovulation)

It attaches the ovary to the pelvic wall and contains ovarian artery, vein and nerves.

Suspensory (infundibulopelvic)

ligament

Mature follicle

Corpus luteum

Corpus albicans

The Ovaries

(Dense connective tissue)

1- Production of the female gametes or oocytes.2- Secretion of female sex hormones (estrogens and progestins).3- Secretion of inhibin (feedback control of pituitary FSH).

OOGENESIS SPERMATOGENESIS

MITOSIS

OogoniaDiploid

Diploid

Before birth

MEIOSIS I

After puberty

It stops inprophase

MEIOSIS ICompleted

Primaryoocyte

Haploid

Secondaryoocyte

It stops inmetaphase Before ovulation

After ovulationMEIOSIS IICompleted

Haploid

Secondaryoocyte

MEIOSIS II

Oogenesis

First polarbody

If fertilizationoccurs

Secondpolarbody

Primary oocytes (diploid) in prophase I of MEIOSIS I.

FSH triggers the start of the ovarian cycle.MEIOSIS I is completed to form one secondary oocyte (haploid) and the first polar body.

Between the third and seventh month of fetal life:

Primary oocytes (diploid) begin MEIOSIS I but it is stopped in prophase I.

During reproductive life: Every month one secondary oocyte begins MEIOSIS II that is stopped in metaphase II. Ovulation occurs, and if the secondary oocyte is fertilized, MEIOSIS II is completed to form the ovum and the second polar body.

At birth:

At puberty:

Oogonia undergo mitosis and produce primary oocytes (diploid).

Primordial follicles

Primary follicles

Secondary follicles

Tertiary follicles

Ovulation

Oogenesis and Sexual CycleReproductive Cycle Sexual Cycle

The events that recur every month when pregnancy does not intervene.It consists of two interrelated cycles controlled by shifting patterns of hormone secretion:

The Ovarian Cycle(The events in the ovaries)

The Uterine (menstrual) Cycle

(The parallel events in the uterus)

The sequence of events from fertilization to giving birth.

1- Follicular phase

4- Ovulation5- Formation of the corpus luteum

Proliferative phaseSecretory phase

Menses

1- Formation of Primary Follicles2- Formation of Secondary Follicles3- Formation of Tertiary Follicles

6- Degeneration of the corpus luteum2- Luteal phase

Follicular fluid

Oocyte at OvulationFirst polar

body

It is a layer of glycoprotein gel secreted by granulosa cells around the oocyte.

It is composed of several layers of granulosa cells.

Zona pellucida Corona radiata

The Ovarian Cycle 1- Follicular Phase

Meiosis I completed

The Ovarian Cycle 2- Luteal Phase

Corpus luteum

The corpus luteum produces progesterone, which primary function is to prepare the uterus for pregnancy by stimulating the maturation of the endometrium and the secretion of uterine glands.

If fertilization does not occur, progesterone and estrogen levels fall, and the corpus luteum disintegrates and becomes a pale scar called corpus albicans.

It also produces moderated amounts of estrogens.

Corpus albicans

It marks the end of the ovarian cycle.

It is produced by adenohypophysis and stimulates the development of the follicles.

It is produced by the hypothalamus and stimulates the adenohypophysis to release FSH and LH (Gonadotropins).

The Ovarian Cycle

Ovulation

FOLLICULAR PHASE LUTEAL PHASE

1- Gonadotropin releasing hormone (GnRH) is produced by the hypothalamus.

It stimulates the adenohypophysis to produce gonadotropins: FSH and LH

2- FSH triggers each month the development of one primordial follicle into primary follicles.

3- At about day 14, a massive release of LH is produced and ovulation is triggered.

4- The high level of LH that triggers ovulation also promotes the formation of corpus luteum and progesterone secretion.

Secondary Tertiary

Primordial

Primary

1- Gonadotropin releasing hormone (GnRH):

2- Follicle stimulating hormone (FSH):

3- Luteinizing hormone (LH): It is produced by adenohypophysis and stimulates ovulation. It is produced by the corpus luteum and prepares the uterus for pregnancy. 4- Progesterone:

Proliferative phase: Menses:

Functional zone

Basilar zone

When enough menstrual fluid accumulates in the uterus, it begins to be discharged by the vagina (menstruation).

It is the beginning of the uterine cycle. The functional zone of the endometrium degenerates.

Pools of blood accumulate in stratum functionalis and necrotic endometrium mixes with blood and serous fluid and forms the menstrual fluid.

At the end of the menstruation, the endometrium consists only of the basilar zone.

Estrogen stimulates mitosis in the basilar zone and the prolific regrowth of blood vessels regenerating the functional zone. By day 14 is 2 to 3 mm thick.

As new cohort of follicles develop in the ovaries, they secrete more and more estrogen.

The endometrium thickens still more in response to progesterone from corpus luteum.

Progesterone stimulates endometrial glands to secrete glycogen. Glands grow wider, longer and more coiled.

By the end of this phase, the endometrium is 5 to 6 mm thick- a soft, wet, nutritious bed available for embryonic development.

The Uterine Cycle

Secretory phase:

UterusOvary

Ovary

Ovarian ligament

MesovariumIt attaches the ovary to the uterus.

It attaches the ovary to the pelvic wall and contains ovarian artery, vein and nerves.

Broad ligament

Broad ligament:

MesovariumIt attaches the ovary to the broad ligament.

It is a sheet of peritoneum that flanks the uterus and holds the uterine tube in its superior margin.

Suspensory (infundibulopelvic)

ligament

6- Uterine Tubes and Uterus

UterusOvary

Ovary

Uterine or Fallopian tubesThey receive and transport the secondary oocytes and

the fertilized ova to the uterus

Infundibulum

Fimbriae

Ampulla

Isthmus

The Uterus1- Receives, protects, and nourishes the fertilized egg2- It is the site of the menstruation, development of the embryo and fetus during pregnancy; and of labor3- It is a passageway for the sperm

Body

Cervix

Fundus

IsthmusCervical canal

External os

Internal osPerimetriumMyometrium

Endometrium

Vagina

Bladder

RectumVaginaUrethra

7- Vagina and Vulva1- Passageway for the baby, menstrual flow, and sperm2- It is the female copulatory organ

Vaginal orifice

The External GenitaliaMons pubis

Labia majora

Labia minora

Glans or clitoris

Prepuce

Urethral opening

Vaginal entrance

Hymen (torn)

Perineum

OvaryUterine or Fallopian

tube (ampulla)

InfundibulumFimbriae

Isthmus

UterusPerimetriumMyometrium

Endometrium

Cervical canal

Cervix

Vagina

Vaginal orifice

Fornix

Clitoris

Mons pubis

Labia minora

Labia majora

Urinary bladder

Urethra

8- Mammary GlandsThey produce milk to nourish the baby

Areola

Nipple

Lobules

Lactiferous duct

Lactiferous sinus

Suspensory ligament

Pectoralis major

Pectoral fat pad