1. FEMALE SEX HORMONES PHG 224 BY DR AGBARAOLORUNPO

2. OBJECTIVES
LIST OF FEMALE SEX HORMONES
LIST THE SITES OF PRODUCTION OF THE HORMONES
DESCRIBE THE SYNTHESIS OF FEMALE SEX HORMONES
DISCUSS THE FUNCTIONS OF FEMALE SEX HORMONES
DESCRIBE THE REGULATION OF FEMALE SEX HORMONE
DESCRIBE THE MECHANISMS OF ACTION OF FEMALE REPRODUCTIVE HORMONE

3. FEMALE SEX HORMONES
ESTROGENS
PROGESTERONES
RELAXIN

4. 1. 17β-estradiol (most potent)
3 types of estrogens
1. 17β-estradiol (most potent)
2. Estrone
3. Estriol (least potent)
They are C18 steroids

5. Synthesis of estrogens
Secreted by theca interna and granulosa cells of ovarian follicles, the corpus luteum and placenta
Formed from androgens and aromatization of androstenedione(catalyzed by aromatase)
Only two percent of estradiol is free and active the rest is bound to and transported by plasma protein(albumin-60% and steroid binding testosterone-38%)
Pathway for the synthesis of estrogen
Acetate→cholesterol
→pregnenolone→
progesterone→
Testosterone(androgen)→Estrogen
About 1/15th of testosterone is secreted by the ovaries into the plasma Or
cholesterol→androstenedione→estradiol

6. Ovarian follicle Uterus Fallopian tube Vagina Breast Bones Metabolism
FUNCTIONS OF ESTROGEN
Ovarian follicle
Uterus
Fallopian tube
Vagina
Breast
Bones
Metabolism

7. Conditions affected by estrogens
Puberty
Pregnancy
Lactation
Menstrual cycle
Malignancy
Menopausal syndrome

8. Development of secondary sex characteristics at puberty:
Enlargement of breast, uterus and vagina.
Body configuration: figure eight shape :narrow shoulder, broad hips, thigh that converges and diverging arms,
distribution of fat in the breasts and buttocks,
less body hair, more scalp hair, pubic hair and axillary hairs
Pelvis-broaden
High pitch voice
Other functions of estrogens
Salt and water retention-weight gain just before menstruation

9. BREAST DEVELOPMENT
development of stroma tissues and duct of breast during puberty and pregnancy
Deposition of fat in the ductile system of breast
Breast enlargement
Pigmentation of areolar
Lactation-preparation of breast ductile system for lactation
Topical estrogen cream-for breast enlargement

10. Ovarian follicle development during menstrual cycles.
Cyclic change(enlargement) in endometrium, cervix and vagina

11. EFFECT ON UTERUS
Enlargement –proliferation of endometrial cells
Increase blood supply to endometrium+ blood vessel supply
Deposition of fat and glycogen
Increase in spontaneous activity and contractility of uterine muscle
Increase sensitivity to oxytocin
FALLOPIAN TUBES
Increase the growth and activity of ciliated epithelium to aid movement of ovum
VAGINA
Proliferation of vaginal epithelium[cuboidal→stratified epithelium]
↓es PH of vagina[acidic vagina
To prevent some vagina infection
Estogeng therapy-for curing such infection

12. Effect on bones
Osteoblastic activity-increases bone growth at puberty
Causes early fusion of epiphysis with the shaft
[this effect is stronger than similar effect of testosterone in male and hence growth of females usually ceases earlier than in males]
Postmenopause: estrogens ↓es→osteoporosis→fragile bone→high risk of bone fractures
Effect on electrolytes and water balance
Sodium and water retention by kidneys
Less significant prior to pregnancy
More significant during pregnancy
Effect on Metabolism
Protein-anabolism=↑total body protein
Fat-deposition of fat in the subcutaneous,tissues,breasts,buttocks and thighs

13. Regulation of estrogen secretion
Estrogen secretion is regulated by FSH [from anterior pituitary gland]
FSH release is stimulated by gonadotropin-releasing hormone[GnRH] from hypothalamus
FSH acts on its receptors in theca cells and granulosa cells via cAMP→estrogens secretion
Estrogen inhibits secretion of FSH and GnRH by negative feedback
Inhibin secreted by granulosa cell s also decreases estrogen secretion by inhibiting FSH and GnRH

14. progesterone C21 Steroid Synthesized from acetate and cholesterol
Synthesized in ovaries, corpus luteum, placenta and adrenal cortex[very small amount]

15. FUNCTIONS OF PROGESTERONE
Fallopian tube
Increases the secretory activity of FT
This is Necessary for nutrition of fetus before implantation
Cervix
Increases the thickness of cervical mucosa.
This prevent sperm transportation to uterus
Utilized in contraceptives
Breast development
Development of lobules and alveoli of breast
Increases the secretory activity of the breast
Thermogenic effect
Increase body temperature after ovulation by acting on hypothalamus
Respiration
Increases ventilation during pregnancy and luteal phase of respiration

16. Uterus
Promotes the secretory activity of uterine endometrium in preparation for implantation
Increases the deposition of lipid and glycogen in endometrium
Blood supply+gland growth in the uterus
Decreases the sensitivity of uterus to oxytocin during pregnancy
Electrolytes and water balance Sodium and water retention Hypothalamus Progesterone Inhibits LH secretion from anterior pituitary gland through negative feedback inhibition.

17. Regulation of progesterone secretion
LH stimulates corpus luteum to secreye progesterone
Secretion of LH is influenced by gonadotropin-releasing hormone[]GnRH from hypothalamus
Progestrone the inhibits LH releas from anterior pituitary by negative feedback inhibition

18. RELAXIN Polypeptides hormones
Produced in corpus luteum,uterus,placenta and mammary glands in women and prostate gland in men
Relaxes pubic symphysis,pelvic joints and softens and dilates uterine cervix during pregnancy
In non-pregnant women-functions unknowns
Increase sperm motility in men