OVARIES

1. Ovaries
Location
The female ovaries are two almond-shaped
bodies about 3.5 centimeters long, which lie
either side of the pelvis.
Structure
Each ovary contains two different kinds of
glandular structures,the graafian folliclas,which
secrete Estrogen,and the Corpus Luteum,which
secrete Progesterone,but also some Estrogen.

2. Hormones of Ovaries
– The ovary produces the following hormones,
which regulate the reproductive process in
female.
1. Estrogen
2. Progesterone
3. Relaxin.

3. Estrogens
– Estrogen is a female sex hormone.
Nature
– 18 carbon steroid.
Types
– Estrogen are of three types.
1. B-Estradiol
2. Estrone
3. Estriol

4. The principal estrogenic hormone in
circulation and the most active form of the
estrogen is Beta-estradiol.All these
hormones are steroid in nature and are
synthesized from cholesterol.
Mechanism of Action
Estrogens act through gene mediator
action.

5. Biosynthesis
Estrogen and progesterone are synthesized in
the ovaries mainly from the cholesterol derived
from blood and a small amount which is derived
from acetyl CoA. Progesterone and testosterone
are first synthesized, then during the follicular
phase of the ovarian cycle,all the testosterone
and much of the progesterone is converted into
estrogens by the granulosa cells.

6. Actions of Estrogens
The principal function of the estrogen is,
Growth of the tissues of the sex organs
and other tissues related to reproduction.
A. Effect on Sex Organs.
During child hood estrogen are secreted
only in minute quantities,but at puberty the
quantity of estrogen increases more.

7. At this the female sex organs change from those
of child to those of an adult.various effects are
as follows,
On vagina
Increases the size of the vagina.
Enlargement of the musculature of the walls of
the vagina.
Changes the simple cuboidal epithelium to
stratified epithelium, which is more resistant to
trauma and infection.
Increases the deposition of glycogen.

8. Effects on External Genitalia
Increases the size of the clitoris and labia
minora.
Increases the deposition of fat on the
mons pubis and labia majora.
Effects on Cervix
Causes slight enlargement of cervix.
Epithelium becomes stratified.

9. Effects on Uterus
Increases the size of the uterus.
Causes the growth of the uterine glands.
B) Effects on secondary sexual
characteristics.
Effect on Breast.
Promotes the development of the tubular duct system.
Increases the deposition of fat.
Responsible for their smooth appearance.

10. Effect on Skin
Increases vascularity of the skin.
Causes softness and smoothness of the skin.
Effect on Pelvis
Broadens the pelvis the pelvic outlet becomes
broad and ovdoid.
Effect on the Voice
The larynx of a female retains its prepubertal size
so the voice remains high pitched.

11. Effect on Skeleton
Causes broadness of the pelvis.
Increases osteoblastic activity.
C) Other effects
Effects on protein metabolism
Increases the synthesis and deposition of
proteins.
Positive nitrogen balance.

12. Effect on fat Metabolism
Increases the synthesis of fat.
Increases the deposition of fat in
subcutaneous tissue,especially the
breasts.
Effect on water and Electrolytes
Increases the retention of Na+ ,Cl-and
water, increasing the E.C.

13. Effect on Blood
Decreases blood cholesterol level.
Raises fibrinogen level.
Regulation of Estrogens
The sexual functions are regulated with the
secretion of gonadotropin-releasing hormone
(GnRH) by the hypothalamus.This hormone in
turn stimulates the anterior pituitary gland to
secrete two othre hormones called gonadotropic
hormones.

14. LH.
FSH.
In turn, LH and FSH help to regulate the
estrogens.
Clinical uses of Estrogen.
1. Used in replacement therapy,
2. In primary amenorrhea.
3. For the development of secondary sex
characteristics.

15. 4. For the relief of menopausal symptoms.
5. Treatment of vaginitis.
6. Decreasing blood cholesterol level.
7. Oral contraceptive.