Repro - 1-29 Normal Menstrual Cycle

Front 1

General scheme of ovulation

Back 1

A group of follicles begin maturation and they are gonadotropin dependent.

One follicle is stimulated more than the others because it has more receptors for FSH. FSH is high right now because estradiol is low (they counter each other).

As this follicle grows, it hogs all the hormones away from the other follicles. This follicle makes more estradiol as it gets bigger and then estradiol reaches a critical level.

LH surges up in response to the high estradiol (positive feedback)

Follicle breaks loose and ovulation occurs. The residue of the dominant follicle becomes CL which produces progesterone throughout the second phase of the cycle (luteal or secretory phase).

If the CL is not rescued by HCG, it will wither away in exactly 14 days.

As progesterone is withdrawn with degeneration of CL, you get bleeding.

THIS IS ALL DRIVEN BY THE HPO AXIS!

Front 2

Where are gonadotropins released from?

Back 2

ant pit

Front 3

Hypothal and GnRH func

Back 3

Axons deliver GnRH into median eminence which secretes into the hypothal portal blood system which ends in ant pituitary.

GnRH has short half life.

Secrtion is pulsatile to effect the gonadotrophs and their prod of LH and FSH

Front 4

Gonadotropin function

Back 4

Gametogenesis

Produce gonadal steroids (estrogen, proges, androgens)

Produce peptides like inhibin of insuli-like-GFs which feedback

Front 5

Proliferative phase

Back 5

main hormone is estrogen and it grows up the endometrium

Front 6

Secretory/luteal phase

Back 6

main hormone is progesterone and it compacts/stabilizes the endometrium.

Front 7

When do first meiotic division and 2nd occur?

Back 7

First - LH surge when polar body is extruded to give haploid genome.

2nd - at fertilization

Front 8

CL reponsible lacteal phase

Back 8

LH stimulated VEGF to get high blood flow to CL.

PGF2alpha stimulates uterine contractions. Responsible for dysmenorrhea (pain)
E PGs inhibit contractions of nonpreg uterus.

Front 9

If person has 32 day cycle, when should she have sex to get a baby?

Back 9

ovulates at day 18, so days 16-19.

Front 10

Why is luteal phase fixed at 14 days?

Back 10

Bc of HcG doesnt rescue CL, it declines 9-11 days post-ovulation.

Front 11

Anorexia

Back 11

Results in erratic production of GnRH, and this oligomenorrhea.

Front 12

Effect of HPO axis

Back 12

directs steroid prod and the effect is mainly on the functionalis layer which cleaves from the basalis layer. (of the endometrium)

Front 13

Cycle length variation

Back 13

in younger and older people, it varies quite a bit.

centers around 28 days though.

Front 14

How much blood is too much to lose?

Back 14

80 mls

Most blood loss is in first few days.

Front 15

Why is menstrual history not a great indicator of blood loss?

Back 15

a volume of blood can have a huge range of number of RBCs.

Front 16

Amenorrhea

Back 16

Absence of menstruation by age 15-16 or absence of 3 expected cycles.

Front 17

Break-through bleeding

Back 17

Unexpected bleedingh occuring while woman is on exog hormone meds

Front 18

Dysfunc uterine bleeding

Back 18

Refers to anovulatory bleeding

Front 19

Menorrhagia

Back 19

Prolonged menstrual blood loss with regualr cycles.

Front 20

Menometorrhagia

Back 20

Irreg menses with excessive blood loss

Front 21

Metorrhagia

Back 21

irreg, frequent bleeding

Front 22

midcycle bleeding

Back 22

light menstrual bleeding occuring in ovulatory women at the midcycle estradiol trough

Front 23

Oligomenorrhea

Back 23

infreq, irreg bleeding and intervals of amenorrhea

Front 24

polymonorrhea

Back 24

menses more freq than 21 days apart.

Front 25

Normal menstruation characteristics

Back 25

1. Progressive vasoconstriction and hemostasis of coiled arterioles (proper clotting)

2. Stable endometrium

3. Rapid withdrawal of hormonal support.

4. Universal endometrial events.

5. Return of hormonal support with increasing estrogen levels to promote healing and induce regrowth of the endometrium.

Front 26

Endometrium responses to estrogen and progesterone

Back 26

Estrogen - Lets the endometrium grow. Increases estrogen and progesterone receptors.

Progesterone - stabilizes the endometrium and compacts it. Via a decrease in progesterone and estrogen receptors. This creates a cleavage plane.

Front 27

PCOS

Back 27

irreg menses, feedback is messed up, some hyperandrogenism.

Only making estrogen most fo the time so the time betwen menses can be very variable (endometrium gets very large and abnormal vasculature as well (abnormal coiled arteries)).

Tonic amts of LH and FSH. Gonadotropin levels are low.

Front 28

Reasons for excessive bleeding of anovulatory endometrium

Back 28

Lack of well developed structural rigidity.

Large quantity of endomtrium to desqamate.

Lack of orderly vasc changes for shedding

Front 29

The earlier age you get to menarche (first menstrual cycle)...

Back 29

you quicker you ovulate.
(the range can be years)

Front 30

Normal adolescent menstrual cycling?

Back 30

21-45 days after menarche.

This cycle varies a lot between menarche and ovulation.

Evaluate a pt outside of this range or someone who had regular periods which are now irreg.

Front 31

Why do girls who haven't ovulate yet bleed?

Back 31

withdrawal bleed from the lack of steroid support. it isn't an ovulatory bleed.

Front 32

Is a normal HPO axis with something superimposed on it normal in pts with menstrual problems?

Back 32

yes. e.g. menorrhagia caused by clotting disorders

(VWD is common - a common sx is alleviation while on OCs)

Front 33

Every female with irreg cycles is...

Back 33

pregnant until proven otherwise!!!

Front 34

Slide 54

Back 34

good summary of disease we've learned in the course.