Functions of the Female Reproductive System

• Production of gametes – known asProduction of gametes known as…

P d ti f f l h h• Production of female sex hormones – such as…

• Reception and maintenance of a…p

Ovaries • Function

• Support

Ovarian Blood Supply

• Ovarian arteries branch from the…

• Ovarian veins run from the ovaries to the…

Ovarian Surface

Germinal Epithelium

Tunica albuginea

Ovarian Follicles

• Developing oocyte surrounded by one or p g y ymore layers of supporting cells.

• Types:Primordial– Primordial

– PrimaryS d– Secondary

– Graafian.

Primordial FolliclesPrimary oocyte surrounded by a layer of simple squamous follicle cellsof simple squamous follicle cells

Primary Folliclesy

Primary oocyte surrounded by simple cuboidal follicle cells (early)

b t tifi d b id l lor by stratified cuboidal granulosa cells (late).

Secondary FolliclesSecondary Follicles

Similar to a late primary follicle except one or more small p y pfluid-filled spaces appear btwn the granulosa cells.

Graafian F lli lFollicle

Contains a huge fluidContains a huge fluid-filled space known as an antrum.

A k a the vesicular follicleA.k.a. the vesicular follicle

Uterine Tubes• Initial portion of female duct

system.

• Extends btwn ovary and uterus

• Supported by the broad ligament.y g

• Receives ovulated oocyte.y

• Divided into 4 portions:Divided into 4 portions:– Fimbriae– Infundibulum– Ampulla – Isthmus.

• Uterine tube lining is ciliated.• Why?y

• Common site of fertilization is the ampulla.

• Implantation in the uterine tube can cause an ectopic pregnancy.p p g y

Uterus• Receives, retains,

nourishes andnourishes and expels...

• Anterior to…

• Posterosuperior to thethe…

• Divided into 3 main regions:– FundusFundus

– BodyBody

– Cervix.

• Anteverted vs. retroverted.

• Uterine cavityy

• Cervical canal• Cervical canal

• External os

• Internal os

• Cervical glands

• Anterior fornix• Posterior fornixPosterior fornix

• Supported by the broad ligament along with others.

• Muscles of the pelvic and urogenital diaphragms provide inferior support.

• Uterine wall is divided into 3 layers:– Perimetrium– Myometrium– Endometrium.Endometrium.

Layers of the Endometrium

• Stratum functionalis – Superficial– Changes in response

to…– Shed during…

• Stratum basalis – Thinner and deeperThinner and deeper – Unresponsive– Forms a new– Forms a new…

Vagina• Extends from…to…

• Receives penis and semen during intercourse.

• Provides exit for infant & menstrual flflow.

Vagina• Mucosa, muscularis,

and adventitia.

• Stratified squamous qepithelium.

• No glands

• Hymen

• Vaginal fornices

External Genitalia• Vulva:

Mons pubis– Mons pubis

L bi j– Labia majora

L bi i– Labia minora

– Vestibule

– Clitoris.

Mammary Glands

• Milk production.

• 15-25 lobes15 25 lobes.

S li t• Suspensory ligament of the breast.

Mammary Glands

• Alveoli.Alveoli.

Lactiferous ducts• Lactiferous ducts.

• Lactiferous sinus.

Oogenesis

Mitosis2

os s2n 2n

Oogonium Lots of oogonia

In the fetus.

Replicates its DNAep ca es s2n 2n

Oogonium Primary Oocyte

Still in the fetus.At this point, the primary oocyte would be part of a primordial p pfollicle

Begins the first division of meiosis but gets BLOCKED

2n2n

Primary Oocyte

A primary oocyte will remain stuck in

Still in the fetus.

meiosis I unless/until it receives the appropriate hormonal signal during the menstrual cycle.

Secondary n

yOocyte

2

Fi l

2n

Primary Oocyte

In response to LH at the midpoint of each menstrual

First polar body

n

cycle, a single primary oocyte completes its first division.

The resulting secondary oocyte is ovulated.

How/Why is the division equal?

How/Why is the ydivision unequal?

Ovum –containing both the

n

both the male and female pronuclei

nn

S d

n

Secondary OocyteSecond polar body

n

IF AND ONLY IF it is fertilized by a sperm, it will undergo the second division of meiosis.

How/Why is the division equal?

How/Why is the ydivision unequal?

The pronuclei fuse togetherZygote with a diploid nucleus2n

n

nucleusn

Ovum – containing both the male and female pronuclei

Follicular PhaseFollicular Phase (days 1-14)

Ovarian CycleOvarian Cycle (28days)

Luteal PhaseLuteal Phase (days 14-28)

Follicular Phase Part 1 – Days 1-7

Hypothalamus releases GnRH

Ant. Pituitary releases FSH and LH

Follicle growth

Growing follicles secrete estrogen

Estrogen causes Estrogen prepares the uterus for

pregnancy

Estrogen causes the anterior

pituitary to store FSH and LH

Follicular Phase Days 7-14 Estrogen levels continue to rise

FSH levels and LH levels continue to fall

Follicle growth continues

Estrogen levels continue to rise

FSH levels and LH levels continue to fall

On average, only one follicle successfully finishes maturation and becomes graafian

Ovulation – Day 14

Estrogen levels reach threshold

Primary oocyte to complete meiosis I

Ant. pituitary releases stored FSH & LHcomplete meiosis I

Surge in plasma LH causes: Secondary oocyte to be ovulated

Remainder of graafian f lli l t bfollicle to be

transformed into corpus luteum

Luteal Phase Part 1 – Days 14-24

Corpus luteum Plasma progesterone secretes progesterone levels rise

Uterine lining becomes more

Progesterone inhibits release of LH and FSH

vascular and more glandular

from anterior pituitary

Prevents further follicular development

or ovulationor ovulation

Luteal Phase Part 2 – Days 24-28If fertilization does not occur

Progesterone levels rise hi h d

Plasma LH levels fall lower

When LH levels reach threshold, corpus luteum begins to degeneratehigher and

higher

levels fall lower and lower

corpus luteum begins to degenerate

Corpus luteum dies andW/ l Corpus luteum dies and becomes a mass of whitish scar

tissue (corpus albicans)

W/o a corpus luteum, progesterone levels fall

Once progesterone levels have fallen:

LH and FSH begin to be released from anterior

pituitaryAnother cycle

will begin

Uterine lining will begin shed

What if fertilization does occur?

Developing placenta

produces HCG

HCG binds to the corpus luteum and keeps it alive

(for a few months, until the placenta is able to take

Progesterone levels stay high

placenta is able to take over)

Uterine lining stays intactPreventing further follicular development or ovulation.

Uterine Cycle

• Changes in the uterine lining caused by the changing levels of ovarian hormones

• 3 phases– Menstrual Phase (Days 1-5)Menstrual Phase (Days 1-5)

Proliferative Phase (Days 6 14)– Proliferative Phase (Days 6-14)

Secretory Phase (Days 14 28)– Secretory Phase (Days 14-28)

Uterine Cycle –menstrual phase• Days 1-5

• Plasma progesterone levels plummet. Why?

• Stratum functionalis is shed. Detached blood and tissue sloughs out of the vaginasloughs out of the vagina

Uterine Cycle –proliferative phase

• Days 6-14

proliferative phase• Plasma estrogen levels are…

• Stratum functionalis of the endometrium gets• Stratum functionalis of the endometrium gets…

• What’s happening to cervical mucus?What s happening to cervical mucus?

Uterine Cycle –secretory phase

• Days 14-28

• Plasma progesterone levels are…

• Stratum functionalis of the endometrium gets…

• What’s happening to cervical mucus?

Extrauterine Effects of Ovarian Hormones

• Estrogen– Promotes bone lengthening

and epiphyseal plate closure

• Progesterone– Increases body

temperaturep p y p

– Inhibits bone resorption

p

– Promotes urination

– Promotes skin hydration

– Stimulates female pattern of fat deposit and hair growth

– ↑ retention of sodium and water

– Raises HDL cholesterol levelsRaises HDL cholesterol levels and reduces LDL cholesterol levels

Important Terms & Events• Puberty – period of life in which the reproductive

organs become adult size and functional

• Menarche – 1st menstrual period

• Menses – normal flow of blood & tissue during menstruation

• Amenorrhea – abnormal cessation of menstruation

• Menopause – normal cessation of menstrual function that usually occurs in the 5th or 6th decadethat usually occurs in the 5 or 6 decade