Menstrual cycle and mammary glands

1. Menstrual Cycle
&
Mammary Glands
Mrs. Sarita Sharma
Assistant Professor
Department Of Pharmacology
Mumbai

2. Female reproductive cycle:
 During their reproductive years, non pregnant females
normally exhibits cyclical changes in the ovaries and uterus.
 Each cycle takes about a month and involve both oogenesis &
preparation of the uterus to received a fertilized ovum.
 Hormones secreted from hypothalamus, anterior pituitary
gland & ovaries control the main events.
The ovarian cycle:
series of the events in
the ovaries that occurs
during and after the
maturation of oocyte.
The uterine/menstrual cycle:
Is a concurrent series of the changes in the
endometrium of the uterus to prepare it for the
arrival of a fertilized ovum that will develop
there until birth.
If fertilization does not occurs, hormonal
changes & endometrium layers slough off.

3. Hormonal regulation of the
Female reproductive cycle:
 Gonadotropin-releasing hormone (GnRH) secreted by
hypothalamus an control ovarian & uterine cycle.
 GnRH Stimulates anterior pituitary to increase secretion of
follicle-stimulating hormone
(FSH)
Initiates the follicular
growth
luteinizing hormone
(LH)
Stimulate further
development of ovarian
follicle
Ovarian
follicles
secretes
estrogen

5. MENSTRUAL CYCLE
• Periodic discharge of blood and cellular debris
from the female genital tract is termed
menstruation.
• Cyclical changes occurring from one
menstruation to the next comprises a
menstrual cycle.
• The duration of menstrual cycle is about 28
± 4 days.

8. DEVELOPMENTOF
FOLLICLE
CLE
PRIMORDIAL FOLLICLE
PRIMARY FOLLICLE
GRAFFIAN FOLLICLE
MATURE FOLLICLE
CORPUS LUTEUM

9. Gametogenesi
sPrimordial germ cell (2n)
Oogonia (2n)
Primary oocyte (2n)
Secondary oocyte (n)
First polar body
Ovum (n)
Mitosis
I Meiosis
II Meiosis

10. Female reproductive cycle:
1)The Menstrual phase
2) Proliferative phase
3) The secretory phase

11. 1) MENSTRUAL PHASE
• It lasts for about 3 – 5 days.
• If the ovum is not fertilized, corpus luteum
regresses from 24th day of the cycle.
• This causes a decrease in estrogen and
progesterone levels.
• It results in shrinkage of endometrium, coiling and
spasm of arteries leading to focal necrosis of the
endometrium.
• The necrosed endometrium is shed along with
blood and other secretions.

12. 2)PROLIFERATIVE PHASE
(follicular phase)
• Proliferative phase starts at the end of menstrual
phase. Its duration is about 10 days.
• At the beginning of this phase most of the
endometrium has been desquamated.
• Later endometrium starts healing and then
proliferates rapidly from 5th –14th day of
menstrual cycle.

13. • This proliferation occurs under the influence of estrogen.
• There is growth of simple tubular glands and blood vessels.
• Endometrium increases in thickness to about 3 – 5mm.
• The endometrial glands produce a thick mucus.
• At the end of proliferative phase ovulation occurs.

14. LH surge and ovulation
• LH surge
• Release of follicular steroid hormone
• Release of proteolytic enzyme and
prostaglandin
• Release of plasma into the follicle
• Weakened wall of follicle
• Degeneration of stigma + swelling of follicle
• Rupture of follicle expulsion of ovum

15. 3) SECRETORY PHASE
(luteal phase)
 This phase lasts for about 14 days.
 It starts after ovulation and extends upto the next
menstrual phase.
 Endometrium thickens upto 6 mm.
 Glands become bigger, tortuous and filled with secretions.
 Stromal cells proliferate, spiral arteries become more coiled
and dilated.
 This is caused due to the action of progesterone and estrogen
on uterine endometrium

21. Menopause:
 Usually occurs between the ages of 45 to 55 years,
marking the end of the child bearing period.
 Progressive reduction of estrogen, as the numbers of
the functional follicles in the ovaries declines with
the age.
 Ovaries become less responsive to LH and FSH,
ovulation and menstrual cycle become irregular ,
eventually ceasing

22. Mammary glands:
 Accessory glands of female reproductive system.
 Made up of glandular tissues responsible for milk
production
 Supported by fatty tissues & fibrous connective
tissues
 Each breast contain 20 lobs, which contain numbers
of the glandular structure called lobules, where milk
id produced.
 Lobules opens into tiny lactiferous duct which drain
milk towards the nipples

23.  Strands of connective tissues called suspensory
ligaments of breast (cooper’s ligaments) run between
skin and support the breast.
 These ligaments become looser with age
 Funtions: after puberty, by the influence of
progesterone and estrogen breast grows
 Main function is synthesis, secretion and ejection of
milk which is called lactation. (By the hormone
prolactin)

25. Thank you