Female Reproductive Cycle

Front 1

what is oogenesis

Back 1

female gametogenesis: ovum develops inside ovarian follicles

Front 2

Stages of oogenesis [5]

Back 2

1. Primordial germ cells (2n, 2c)
- migration to genital ridge at week 4

2. Oogonia (2n, 4c)
- mitosis: DNA synthesis

3. Primary oocyte (2n, 4c) w. primordial follicle
- fetal stage:
*start meiosis I, [primary follicle]
*arrest at prophase I (8-9 weeks) until menarche [secondary follicle]
- birth: oocyte + follicles grow

4. Secondary oocyte (2n, 4c)
- puberty (tertiary follicle)
*follicular maturation
*complete, meiosis, start meiosis II
*arrest at metaphase II until fertilization

5. Pronucleate egg (ootid) (n, 2c)
- complete meiosis II at fertilization

Front 3

Germ cell population in humans [3]

Back 3

- rapidly rise/peak at 6 months
- decline rapidly before birth
- decline gradually to 0 at menopause

Front 4

What is folliculogenesis
- phases of the folliculogenesis [4]

Back 4

- maturation of ovarian follicles
- ends at menopause: irresponsive to hormonal cues
- function to SUPPORT oocyte

After birth
1. primordial follicle + primary oocyte in ovary

Menarche: follicogenesis, ovulation, atresia
2. recruitment: preantral follicles depart resting pool & begin to grow
3. selection: a member develops to preovu. follicle
4. atresia: other members degenerate/die

Front 5

Stages of the follicle [7]

Back 5

1. Primordial
- G: single layer of granulosa cells

2. Primary
- Granulosa: cuboidal granulosa cells (zona granulosa, zona pellucida)
- Theca cells: theca interna

3. Secondary
- Granulosa: 6-12 layers of granulosa cells
- Theca cell: theca interna & externa
- Antrum: follicular antrum

4. Tertiary
- Granulosa: cumulus oophorus, corona radiata
- Antrum: grows

5. Preovulatory
- Granulosa: stigma (opening) for ovulation

6. Corpus luteum
- Granulosa: vascularization
- Theca: lutenized granulosa & thecal cells

7. Corpus albicans
- Granulosa: degenerated, funcitonless

Front 6

Phases of follicular development [6]
1. [4]
2. [4]
3. [3]
4. [5]
5. [3]
6. [2]

Back 6

1. Preantral phase
- growth in 1° OOCYTE
- ZP, ZG, theca develops
- Granulosa cell develop estrogen + FSH receptors
- independent of gonadotropin

2. Antral phase
- dependent upon gonadotropin
- growth in GRANULOSA CELLS & ANTRUM
- Estrogen: 2-cells theory, +ve feedback
- FSH + estrogen → LH receptor develop in follicle

3. Preovulatory phase
- growth in ANTRUM [metaphase II]
- dependent on LH surge
- progesterone (few hours after LH peak)

4. Ovulation
- form stigma (bulging pt on ovary for rupture)
- ↑follicular fluid, rupture of foll membrane
- 2° oocyte + cumulus oophorus ovulated
- PG & proteolytic enzymes produced
- Oxytocin causes foll membrane contraction

5. Luteal phase
- vasculization of G layer → corpus hemorrhagicum
- Lutenization → corpus luteum (80%G, 20% T cell)
- estrogen & progesterone

6. Fate of corpus luteum
- Fertilization → embryo + placenta + hCG (to sustain corpus luteum)
- No fertilization → luteolysis (corpus albicans)

Front 7

what is the 2-cell theory of estrogen production [4]

Back 7

Theca cell
1a. LH stimulates ATP → cAMP, which stimulates cholesterol → androstenedione (enter circulation and through BM to granulosa cell)

Granulosa cell
1b. FSH stimulates ATP → cAMP, which stimulates aromotase
2. Androstenedione → becomes estrogen. This is stimulated by aromatase
3. estrogen enters circulation and follicular fluid.

Front 8

Reproductive cycle of hormones
- what organs are involved? what do they produce?
- phases:
1. [3]
2. [2]
3. [2]

Back 8

- Hypothalamus: GnRH
- Pituitary: LH, FSH
- Ovary: progesterone, estrogen

1. Follicular phase: 7-23 days
- GnRH: ↑FSH/LHrelease
- FSH ↑ follicular growth
- Estrogen (NEG feedback)
*↓FSH release, ↓GnRH release
*↑FSH/LH synthesis

2. Ovulation phase
- high estrogen for 2-3 days (POS. feedback) ↑FSH/LH release/synthesis, ↑GnRH release/pituitary sensitivity
- Low progesterone ↑estrogen-induced LH surge, ↑GnRH pituitary sensitivity

3. Luteal phase
- high estrogen & progesterone (-ve feedback)
*↓GnRH release, ↓estrogen action by high progesterone,
- Luteolysis phase (cessation of hormone production) ↑FSH because remove of inhibition)

Front 9

detection of ovulation

Back 9

- menstrual cycle
- basal body temperature
- urinary LH kit
- blood: progesterone levels
- USG: development of follicle

Front 10

Phases of uterine cycle

Back 10

1. menstrual cycle (1-5)

2. proliferative (follicular) day 6-14
*functional layer proliferate, follicle develop

3. secretory (luteal) phase, day 15-28
- maturation/secretion of uterine glands during corpus luteum

Front 11

characteristic of normal menstruation [5]

Back 11

- 3-7 days
- flow: moderate level → increase → slowly reduce
- cyclic pattern (28 ± 7 days)
- amount of blood loss (40±20mL)
- Sx: intense sensation, emotional disturbance

Front 12

Estrogen
- origin [3]
- action [5]
- feedback [3]
- phase [3]

Back 12

Origin
- 2-cell theory
*granulosa (FSH) → estrogen
*thecal (LH) → androstenedione → estrogen
- placenta
- liver, adrenal glands, breasts

Action
- grow/mature sex organs
- female secondary sexual characteristics
- (+) sperm transport through cervical mucus *cervical mucus exhibits ferning (more watery), (+) ovum transport in oviduct
- (-) growth of cohort follicle
- (+) endometrial proliferation

Feedback
- ↑GnRH (+ve feedback) for LH surge in high conc
- ↓GnRH (-ve feedback) in normal conc
- ↑progesterone syn. & receptors

Phase
- start in ANTRAL follicular phase
- highest in ovulation phase for 2-3 days
- continued secretion in luteal phase

Front 13

Progesterone
- origin [3]
- action [2]
- feedback [2]
- phase [2]

Back 13

Origin
- corpus luteum
- placenta
- adrenal glands

Action
- prepare for pregnancy: breast for lactation, maintain uterus lining, uterine quiescence,development of embryo
- ovulation

Feedback
- ↓oxytocin sensitivity
- ↓prostaglandin

Phase:
- start in preov. phase few hrs after LH surge
- maintain levels in luteal phase by hCG (also maintains corpus luteum

Front 14

FSH
- origin
- action
- phase

Back 14

- ant pituitary gland
- follicular growth (esp granulosa cells)
- effect in antral follicular phase: cause secretion of estrogen

Front 15

LH
- origin
- action
- phase

Back 15

- ant pituitary gland

Action: ovulation + growth of corpus luteum (esp thecal cells)

Phase:
- surge in preovulatory phase
- promoted by high estrogen & low progesterone lvl

Front 16

hCG
- origin
- action
- feedback
- phase

Back 16

- placenta
- ovulation + maintain corpus luteum
- ↑steroid, relaxin, fetal testosterone, DHEA-S

- surge in preovulatory phase
- promoted by high estrogen & low progesterone lvl