Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro Clinicals > Gynae > Flashcards

Gynae Flashcards

1
Q

what are the steps involved in creating progesterone from cholesterol.

A
  1. Cholesterol –> pregnenolone : mediated by Theca cell enzyme cholesterol desmolase
  2. Pregnenolone –> progesterone : mediated by Theca cell enzyme 3B-hydroxysteriod dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the steps involved in creating estrogen from cholesterol

A
  1. Cholesterol  pregnenolone via Theca cell hormone cholesterol demolase
  2. Pregnolone  17-hydroxyprenenolone
  3. 17-Hydroxypregnenolone  DHEA (dehydroepiandrosterone)
  4. DHEA  Androstenedione via 3B hydroxysteroid dehydrogenase
  5. Androstenedione  testosterone via 17B-hydroxysteroid dehydrogenase from granulosa cell
  6. Testosterone  17B-ESTRADIOL via aromatase from granulosa cells (Granuloma cells are stimulated to produce aromatase by FSH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Systemic effects of oestrogen

A

cardiovascular protection
bone density
skin elsasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the average age of menarche

A

10-15 normal range 12.2 average

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how long is a cycle

A

28 +/- days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how much blood lost per cycle

A

25-80ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the function of the LH and FSH in the first 10 days of menstrual cycle i.e. what do they make

A

● LH  Theca cells  production of Androstenedione (androgen hormone)
● FSH  Granulosa cells  production of Aromatase
o Aromatase converts Androstenedione  17B-estradiol (ESTOGEN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is CL
- what hormones does it produce
- how long is it’s life span
-

A

● Made of lutenised theca and granulosa cells
● Produces oestrogen, progesterone and inhibin
● Has fixed lifespan of 14 days (programmed cell death)  becomes corpus albicans (white body)
● Lutenised theca cells continue to produce androstenedione w lutenised granulosa cells promote conversion to 17B oestradiol
Remember that during the menstrual hormonal cycle that low levels of E produced in the early follicular phase inhibit LH but at higher levels of follicular development, there is an LH surge which triggers ovulation
● Response to low LH  ↑ activity of P450scc 🡪 ↑ conversion of cholesterol  pregnenolone  progesterone
Low LH triggers increased production of progesterone by triggering the theca cells to turn pregnenolone to progesterone using 3B-hydroxydehyrogenase
The take home message is that the CL produces more progesterone than estrogen because the time for follicular development is over we have entered into the secretory phase of the uterin cycle which mainly serves to prepare the uterus for any impending implantation of a zygote

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Location and function of GnRH

A

Hypothalamus
Gonadotrophin releasing hormone
● Control of pituitary hormones
● Released at steady rate before puberty, after released in pulses
● Controls ovarian and uterine cycles 🡪 stimulates release of LH and FSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Location and function of FSH and LH

A

Follicle Stimulating Hormone
● Stimulate maturation of primary follicles (follicular phase)
● Acts on granulosa cells 🡪 produce aromatase

Lutenising Hormone
● Triggers ovulation
● Acts on theca cells 🡪 produce 3B- dehydoxydehrogenase androstendion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

function and location of secretion for Inhibin

A

● -ve feedback to inhibit FSH secretion (prevent follicle development in luteal phase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

On a hormonal level what occurs in the first 10 days of the menstrual cycle

A

● Pulsatile release of GnRH 🡪 ant pit FSH production
● INITIAL: ↑ FSH in last few days of menstrual cycle 🡪 stimulates ovarian follicle recruitement + development
o Declining steroid production by corpus luteum 🡪 fall in ihibin 🡪 rise of FSH during last days of menstrual cycle
o ↑ GnRH secretion due to oestradiol and progesterone decline
● Steady Low LH: due to inhibitory effects of low level oestrogen
● Granulosa cells of the developing follicle produce oestrogen 🡪 ↑ Oestrogen
o 🡪 endometrial proliferation
o FSH 🡪 activation of aromatase enzymes in granulosa cells to produce oestrogen
● ↑ Oestrogen 🡪 -ve feedback 🡪 Dropping FSH
o Dropping levels of FSH 🡪 regression of all developing follicles leaving the dominant follicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens hormonally on day 10-14 of the menstrual cycle

A

● Rise in GnRH and Oestrogen (dominant follicle)  +ve feedback  ↑ LH (LH surge 36 h before ovulation), also ↑ in FSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what hormonal and physiological things occur in the menstrual phase of the cycle

A

● ↓ Progesterone and Oestrogen: following end of previous cycle and degeneration of corpus luteum
o Endometrium cannot be maintain  SHEDDING
● Inflam mediators (PGs, ILs and TNF)  vasospasm in spiral end arteries  hypoxia and endometrial devitalization (cramps)
● Endometrium lost down to basalis layer (1/3 of loss reabsorbed)
● Complex vascular changes controlled by abovey secondary messengers 🡪 natural haemostatic mechanism (platelet plug, coagulation cascade, fibrinolysis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what hormonal and physiological changes occur in the proliferative phase of the menstrual cycle

A

Proliferative phase: response to ↑ Oestrogen
● Thickening of endometrium + Growth of endometrial glands
● Emergence of spiral arteries from basal arteries to feed function endometrium
● Changed consistency of cervical mucous 🡪 more hospitable for sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are optimal days for fertilization

A

Optimise for fertilization: highest between day 11 – 15 of 28 day cycle

17
Q

Luteal phase
- when is this
- what hormonal and physiologic changes do we see?

A

14 days before onset of menstruation

● Post-Ovulation: drop in GnRH and LH
● Follicle collapses 🡪 becomes corpus luteum which slowly degrades
o Produces oestrogen, progesterone and inhibin
o Has fixed lifespan of 14 days (programmed cell death) 🡪 becomes corpus albicans (white body)
● Hormone:
o ↑ Progesterone and inhibin
o Oestrogen following drop post ovulation remains detectable (but progesterone is dominant hormone)
● ↑ Progesterone :
o Suppress GnRH release 🡪 decreased in LH and FSH
o Stabilise the endometrium in preparation for pregnancy

ABSENCE OF PREGNANCY
● Corpus luteum degenerates 🡪 Corpus albicans (No hormone production) 🡪 Rapid ↓ Progesterone and oestrogen 🡪 ↑ GnRH levels + initiation of menstruation

If implantation occurs: hCG (luteotrophic) rescue of Corpus Luteum allows for production of progesterone to support endometrium

18
Q

what hormonal and physiological changes occur in the secretory phase of the menstrual cycle

A

SECRETORY PHASE
● Progesterone + oestrogen  act on oestrogen primed endometrium  induce secretory changes 🡪 thickening and ↑ vascularity
● Endometrial stabilisation + ↑ vascularity
● Spiral arteries grow longer
● Uterine glands secrete more mucous
● Past day 15: thickening of cervical mucosa 🡪 less hospitable to sperm
o ↓ progesterone  spiral arteries collapse

19
Q

what are the 3 broad main steps in fertilisation

A
  1. Capacitation
    ● Occurs in the uterus – biochemical alterations in acrosomal cap
    ● Allows for spermatozoa to acquire capacity to fertilise ovum
  2. Meets ovum in ampulla of fallopian tube
  3. Acrosome Reaction: Sperm binds to egg and releases hyaluronidase to penetrate zona pellucida (that surrounds the ovum)
  4. Plasma membranes fuse 🡪 fertilisation
20
Q

what is a zygote? and what happens day 1-4 post fertilization

A

● Fertilisation w sperm within 12-24 hours (1 day post fertilisation)
● Fertilised oocyte (cellular fusion of sperm and oocyte) undergoes cleavage
● CLEAVAGE: Zygote undergoes mitotic division along the fallopian tube
o Contained within the zona pellucida
o Note: increase in cell number but not size
● Morulla (DAY 4) = 16 cells

21
Q

What is a blastocyst and what is it made up of?
which day is implantation?

A

● 32+ cells
● Still surrounded by zona pellucida, stay in uterus for 1 day
● DAY 7: Implants into growing uterine wall (post shedding of zona pellucida
At implantation consists of:
● Embryoblast (Inner cells)  become foetus
● Trophoblasts (outer cells)  become placenta

22
Q

what needs to be the oestrogen to progesterone ratio for implantation to take place. How is this ration acheived

A

● Corpus Luteum: produces ↑ progesterone (compared to oestrogen)
● Low Oestrogen: Progesterone ratio
o Necessary for implantation

23
Q

what is amenorrhoea?

A

primary = no menses by 16 if nil secondary sexual characteristics or by 14 if none

secondary = absence for 6 months for irregular menstruators or 3 months in previously normal cycle

24
Q

what is oligomennorrhea

A

cycles > 35 days

25
Q

List common causes of oligo/amennorrhea

A

Causes
● PCOS
● Borderline/ low BMI
● Obesity without PCOS
● Ovarian resistance leading anovulation: incipient POF (rare but important)
● Mild hyperprolactinaemia or thyroid disease

26
Q

what are normal parameters and variations in menstrual cycle

A

● Varies: usually 21-32 days w basically regular pattern
● Cycles that vary do so due to the follicular phase
o Luteal phase remains consistently 14 days
Normal periods of irregularity
● After menarche: cycles are irregular for months – yrs until maturation of the HPO axis occurs
● Peri-menopausal: irregular (increased cycle length) due to ovarian resistant to gonadotrophins and anovulatory cycles
o NOTE: erratic, chaotic or constant bleeding in women > 45 MUST be investigated to exclude genital cancer before being deamed menopausal changes
Normal Bleeding
● 1-7 days normal (average 3-5 days)
● Pain is normal - vasospasm and ischaemia (but is highly variable)
o Must be addressed if interfering w normal function

Neuro Clinicals (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions