Your SlideShare is downloading. ×
0
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Menstrual cycle
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Menstrual cycle

6,073

Published on

1 Comment
7 Likes
Statistics
Notes
  • Jogando.net/mu - 22

    Olá, venho divulgar o melhor servidor de MU on-line do
    Brasil.
    -Season 6 Ep. 3 em todos os Servers. Sendo 7 servers diferenciados proporcionando sua diversão,
    VEJA ALGUMAS NOVIDADES :
    - NOVOS KITS : DEVASTATOR e SUPREMO DIAMOND V2 com Rings e Pendat Mysthical ;
    - Novos Shields Power v3 18 opts;
    - Novas Asas, Rings e Shields JDiamonds;
    - Novas compras com troca de asas e shields para asas e shields JDiamond.
    - Conheça também o site de Animes Cloud: http://www.animescloud.com, mais de 20.000 videos online.
    - Eventos e promoçoes DIA DAS CRIANÇAS diversao para todos na Jogando.net
    * JDIAMONDS EM DOBRO
    * jCASHS EM DOBRO
    * COMCORRA A UM IPAD
    * E DIVERSOS PREMIOS
    ENTRE JÁ NO SITE : http://www.jogando.net/mu/ >> CADASTRE-SE E GANHE 5 DIAS DE VIP
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total Views
6,073
On Slideshare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
509
Comments
1
Likes
7
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. The Menstrual Cycle www.freelivedoctor.com
  • 2. www.freelivedoctor.com
  • 3. The Menstrual Cycle: Two Phases <ul><li>Ideally 14 days each </li></ul><ul><li>Follicular and Luteal </li></ul><ul><ul><li>Describe changes in the ovary </li></ul></ul><ul><li>Proliferative and Secretory </li></ul><ul><ul><li>Describe changes in the endometrium </li></ul></ul>www.freelivedoctor.com
  • 4. Hormones in the Menstrual Cycle www.freelivedoctor.com
  • 5. Follicular phase <ul><li>Begins with the onset of menses and ends on the day of the luteinizing hormone (LH) surge </li></ul><ul><li>During late luteal phase/ early follicular phase: </li></ul><ul><ul><li>withdrawal of estrogen and progesterone in late luteal phase </li></ul></ul><ul><ul><li>In early follicular phase, ovary is least hormonally active  low serum estradiol and progesterone </li></ul></ul><ul><ul><li>release from negative feedback effects of estrogen + progesterone  increase in GnRH pulse frequency in early follicular phase </li></ul></ul><ul><ul><li>Increased GnRH pulse  30% increase in serum FSH concentrations </li></ul></ul><ul><li>FSH release from the pituitary stimulates growth of 5-15 primordial follicles </li></ul><ul><ul><li>By late follicular phase, a single dominant follicle has been selected. </li></ul></ul>www.freelivedoctor.com
  • 6. Follicular Phase <ul><li>The developing dominant follicle produces estrogen in a 2-cell process </li></ul><ul><ul><li>Theca interna cells produce androstenedione in response to LH stimulation </li></ul></ul><ul><ul><li>Granulosa cells convert androstenedione  estradiol when stimulated by FSH </li></ul></ul><ul><li>Estrogen causes the uterine lining to thicken / proliferate </li></ul><ul><li>GnRH pulse frequency increase  rise in LH </li></ul><ul><li>Rise in LH also stimulates androgen synthesis  androgens are converted to estrogens </li></ul>www.freelivedoctor.com
  • 7. Follicular Phase <ul><li>Serum estradiol concentrations peak approximately 1 day before ovulation </li></ul><ul><li>Midcycle (~day 14) there is an LH spike in response to this estrogen surge </li></ul><ul><li>Ovulation occurs as increase in LH level causes the follicle to rupture and release mature ovum </li></ul>www.freelivedoctor.com
  • 8. LH Surge <ul><li>Involves a poorly-understood neuroendocrine phenomenon in which there is a switch from negative feedback control of LH secretion by estradiol and progesterone to positive feedback </li></ul><ul><li>Rising estradiol levels at the end of the follicular phase result in a 10-fold increase in serum LH concentration </li></ul>www.freelivedoctor.com
  • 9. LH Surge: Effect on the Ovary <ul><li>In response to LH: </li></ul><ul><ul><li>Oocyte in the dominant follicle completes 1 st meiotic division </li></ul></ul><ul><ul><li>Increase in local secretion of plasminogen activator and cytokines required for ovulation </li></ul></ul><ul><ul><li>Oocyte released from follicle at ovarian surface ~ 36 hrs after LH surge. </li></ul></ul><ul><ul><li>Even before oocyte is released, granulosa cells around it begin to “luteinize” and produce progesterone. Progesterone slows LH pulses/ decreases LH pulse frequency </li></ul></ul>www.freelivedoctor.com
  • 10. Ovulation <ul><li>LH spike stimulates ovulation, the release of the ovum from the follicle </li></ul><ul><li>After ovulation, the luteal phase begins, and remnants of the follicle left behind in the ovary develop into the corpus luteum </li></ul>www.freelivedoctor.com
  • 11. Ovulation <ul><li>Ovum usually passes into adjoining fallopian tube and is swept down to the uterus by the cilia lining the tube </li></ul><ul><li>Takes 3-4 days for ovum to travel down tube to the uterus </li></ul><ul><li>Fertilization must occur within 24 hrs of ovulation or ovum degenerates </li></ul>www.freelivedoctor.com
  • 12. Luteal Phase <ul><li>After ovulation, granulosa and theca interna cells lining the wall of the follicle form the corpus luteum cyst (stimulated by LH) </li></ul><ul><li>The corpus luteum synthesizes estrogen and large amounts of progesterone </li></ul><ul><ul><li> Progesterone stimulates the endometrium to become more glandular/secretory in preparation for implantation of fertilized ovum </li></ul></ul>www.freelivedoctor.com
  • 13. Luteal Phase <ul><li>If fertilization occurs: </li></ul><ul><ul><li>developing trophoblast synthesizes human chorionic gonadotropin (hcg) </li></ul></ul><ul><ul><li>hcg maintains the corpus luteum so it may continue producing estrogen and progesterone to support the endometrium </li></ul></ul><ul><li>By ~ 8-10 weeks gestation, the placenta is developed, and takes over production of estrogen and progesterone </li></ul>www.freelivedoctor.com
  • 14. Luteal Phase <ul><li>If fertilization does not occur: </li></ul><ul><ul><li>corpus luteum is not maintained by hcg </li></ul></ul><ul><ul><li>Corpus luteum degenerates after ~ 14 days </li></ul></ul><ul><ul><li>Estrogen and progesterone levels fall </li></ul></ul><ul><ul><li>Withdrawal of progesterone causes secretory endometrium to slough </li></ul></ul><ul><ul><li>FSH levels slowly rise again in absence of negative feedback </li></ul></ul><ul><ul><li>↓ </li></ul></ul><ul><ul><li> </li></ul></ul><ul><ul><li> MENSTRUATION </li></ul></ul>www.freelivedoctor.com

×