female reproductive biology

Question 1

ovarian follicles

Answer 1

stat as primordial follicles
grow into preantral follicle
astral (secondary) follicle

Question 2

oestrogen’s produced in

Answer 2

granuloma cells (also corpus luteum)
require aromatase activity
regulated by LH and FSH

Question 3

progesterone produced in

Answer 3

corpus luteum - thing formed after ovulation, everything left minus the ovum (tiny amount from follicular theca cells)

Question 4

progesterone production regulated by

Answer 4

LH (via cAMP)

Question 5

corpus luteum

Answer 5

the thing left behind after ovulation

the follicle minus the egg

Question 6

granuloma cells can’t

Answer 6

form androgens from progesterone

Question 7

theca cells can’t

Answer 7

produce oestrogen from androgens because they don’t have aromatase

Question 8

oestrogen production is regulated by

Answer 8

LH and FSH

Question 9

2 types of oestrogen receptors

Answer 9

Era and ERb

Question 10

effects of oestrogen’s

Answer 10

facilitate growth of ovarian follicles and uterine tube motility
cyclical changes in the endometrium
increases flood flow and contractility of the myometrium
oestrogen dominated uterus is more sensitive to oxytocin
increases breast duct growth

Question 11

progesterone is stimulated by

Answer 11

LH

Question 12

progesterone binds

Answer 12

PRa, PRb which form transcription factors

Question 13

mifepristone

Answer 13

blocks progesterone binding - morning after pill

Question 14

GnRH

Answer 14

secreted in episodic bursts
oestrogen increases cycling prequency
progesterone decreases frequency

Question 15

flliculogenesis

Answer 15

takes 1 year (so includes 11 other cycles)

Question 16

phases of menstrual cycle

Answer 16

follicular, ovulation, luteal, pregnancy or regression

Question 17

primordial follicles contain

Answer 17

immature ovum

Question 18

follicular phase

Answer 18

several follicles enlarge, cavity forms around the ovum (antrum), filled with follicular fluid
10-15 days before ovulation - dominant follicle starts to grow rapidly, other regress (apoptosis)
oestrogen is now produced from ovary granulose cells (via theca cells)
oocyte increases zona pellucid (glycoprotein shell)

Question 19

atretic follicles

Answer 19

not dominant ones -apoptose

Question 20

ovulation

Answer 20

day of ovulation - distended follicle ruptures, ovum extruded into abdominal cavity
ovum picked up by oviducts and transported to uterus

Question 21

oogenesis

Answer 21

all oocytes made by the 7th month
begin moeiss around birth but arrest at prophase (1° oocyte)
begin ovulation at puberty - 1° oocytes reenter ovulation
completes meiosis 1 to become a 2° oocyte and begins meiosis 2 and arrests at metaphase
granulose cells produce AMH which kills off all the other cells

Question 22

if ovum is fertilised

Answer 22

meiosis 2 completed (now an ovum)

Question 23

atresia

Answer 23

dying cells before they can produce functional ova

Question 24

luteal phase

Answer 24

formation of a corpus luteum
after ovulation, ruptured follicle fills with blood to form a corpus haemoragicum
granulosa/theca cells proliferate and form lipid filled corpus luteum
secretes progesterone and oestrogen
becomes vasculogenic and grows until it dies
replaced by scar tissue and becomes corpus albicans

Question 25

during the first 14 days

Answer 25

granolulossa cells producing lots of oestrogen which creates positive feedback to LH which triggers ovulation

Question 26

LH surge

Answer 26

triggers ovulation
Lh and FSH causes rapid swelling of the follicle
moeisis reinitiated
- theca cells release proteolytic enzymes (coollagenase) which dissolves follicular capsule wall and causes degeneration of preovulatory opening
- prostaglandins trigger follicolare tissue to create smooth muscle contraction of the follicle and cause ovum expulsion

Question 27

oestrogen causing LH surge

Answer 27

moderate constant oestrogen - surpasses GnRH and LH

aberrantly elevated oestrogen’s - increase GnRH and LH

Question 28

LH surge

Answer 28

GnRH release rises throughout follicular phase

early follicular phase

Question 29

myometrium

Answer 29

outer muscle wall

Question 30

endometrium

Answer 30

inner lining
rich blood supply , highly glandular
undergoes cyclical growth, loss and repair - menstraul cycle
influences by cyclic changes in oestrogen and progesterone

Question 31

the uterine cycle

Answer 31

proliferative - rapid endometrial thickening, proliferation of blood vessels and endometrial cells
secretory - CL develops corresponds to the luteal phase of the ovarian cycle and endometrial glands secrete fluids, becomes oedematous prpares uterus for implantation
menstrual - CL regresses, sudden drop n oestrogen and progesterone levels, endometrium thins and degenerates

Question 32

corpus luteum regression

Answer 32

drives the next cycle

once luteolysis begins, FSH and LH levels re set, a new crop of follicles develop

Question 33

eggs live for

Answer 33

12-24 hours after ovulation, so conception only occurs during this short window
fertilisation occurs in the Fallopian tube

Question 34

steps of sperm meeting the ovum

Answer 34

1. chemoattraction
2. adherence to zona pellucide ZP3 receptors
3. penetration and acrosome reaction
4. adherence to cell membrane, digestion (cortical reaction) fusion

cortical reaction - serine proteases destroy ZP3 receptors to prevent polyspermy

Question 35

endocrine changes in implantation

Answer 35

corpus luteum fails to regress - enlarges - secretes oestrogen, progesterone, relaxin, (inhibits myometrial contraction)
implanting syncytiotrophoblasts from placenta

Question 36

human chorionic gonadotrophin

Answer 36

maintains corpus luteum of pregnancy

stimulates secretion of testosterone by the developing testes in XY embryos