Endocrinology of Pregnancy

Question 1

Inside to outside layers of the testis, what cells and what’s made there?

Answer 1

Inside is spermatozoa are formed, next layer outwards is the Sertoli cells which make sperm, and the outermost layer are the Leydig cells which make testosterone

Question 2

Sertoli cells make..

Answer 2

sperm

Question 3

Leydig cells make…

Answer 3

testosterone

Question 4

Sertoli cells are stimulated by …

Answer 4

FSH

Question 5

Leydig cells are stimulated by …

Answer 5

LH

Question 6

What do men need oestrogen for and what is it made by

Answer 6

Converted from testosterone by aromatase and is needed for bone

Question 7

Features of aromatase deficiency in males (3)

Answer 7

• Tall oestrogen needed to close growth plates
• Infertility or low sperm count
• Osteoporosis Fractures from a young age

Question 8

Features of aromatase deficiency in females (4)

Answer 8

• Virilisation -> Changes that make a female develop male characteristics
• Hirsutism
• Deepening of the voice
• Amenorrhoea

Question 9

Where does the spermatozoa travel from testes?

Answer 9

Oviduct

Question 10

Where is seminal fluid produced (4)

Answer 10

• Small contribution from the epididymis/testis
• MAINLY from the accessory sex glands:
  Seminal vesicles
  Prostate
  Bulbourethral glands

Question 11

What happens to sperm to gain fertilising ability? (3)

Answer 11

1. Loss of glycoprotein ‘coat’
2. Change in surface membrane characteristics
3. Develop whiplash movements of the tail

Question 12

Where is a sperm capacitated

Answer 12

• Takes place in ionic and proteolytic environment of the Fallopian tube

Question 13

What is required for sperm capacitation (2)

Answer 13

• Oestrogen dependent

- Ca2+ dependent

Question 14

What receptor do sperm bind to on the ovum

Answer 14

• Sperm binds to ZP3 (glycoprotein receptor on zona pellucida of ovum)

Question 15

what happens when sperm binds to the ZP3 receptor on the ovum? what stimulates this?

Answer 15

• Ca2+ influx into the sperm (stimulated by progesterone)

Question 16

What enzyme breaks down the polysaccharide of the zone pellucida

Answer 16

hyaluronidase

Question 17

What breaks down the zone pellucida

Answer 17

• Release of hyaluronidase (breaks down polysaccharides) and proteolytic enzymes (break down protein)

Question 18

Describe the acrosome reaction starting with sperm binding

Answer 18

• Sperm binds to ZP3 (glycoprotein receptor on zona pellucida of ovum)
• Ca2+ influx into the sperm (stimulated by progesterone)
• Release of hyaluronidase (breaks down polysaccharides) and proteolytic enzymes (break down protein)
• Spermatozoon penetrates zona pellucida

Question 19

Where in the vagina does fertilisation occur

Answer 19

Fallopian tube

Question 20

What reaction does fertilisation trigger

Answer 20

cortical reaction

Question 21

What happens in the cortical reaction

Answer 21

 Cortical granules release molecules which degrade the zona pellucida (e.g. ZP2/ZP3) PREVENTS FURTHER SPERM FROM BINDING

Question 22

How long does it take for the zygote to move down Fallopian tube to uterus

Answer 22

3-4 days

Question 23

How long is the zygote a free living unbound ting

Answer 23

About 9-10 days

Question 24

2 phases of implantation?

Answer 24

ATTACHMENT phase

DECIDUALISATION phase

Question 25

What happens during the ATTACHMENT phase

Answer 25

Outer trophoblast cells contact uterine surface epithelium | Followed by DECIDUALISATION phase

Question 26

What happens during the DECIDUALISATION phase (brief)

Answer 26

Changes in underlying uterine stromal tissue (within a few hours)- allows it to receive the fertilised egg

Question 27

Wha hormone is dominant in attachment of the egg to the uterus over what

Answer 27

Progesterone > oestrogen

Question 28

what is leukaemia inhibitory factor

Answer 28

from endometrial secretory glands (and blastocyst?) stimulates adhesion of blastocyst to endometrial cells

Question 29

what secretes leukaemia inhibitory factor

Answer 29

endometrial secretory glands

Question 30

What stimulates adhesion of blastocyst to endometrial cells

Answer 30

leukaemia inhibitory factor from endometrial secretory glands (and a bit of IL-11 )

Question 31

2 hormones involved in attachment phase?

Answer 31

- IL-11 and leukaemia inhibitory factor

Question 32

decidua is ...

Answer 32

thick layer of modified mucous membrane which lines the uterus during pregnancy and is shed with afterbirth

Question 33

What endometrial changes take place due to progesterone? (4)

Answer 33

Glandular epithelial secretion (nutrients) Glycogen accumulation in stromal cell cytoplasm (stromal cells are layer under epithelium) Growth of capillaries (increased blood supply for placenta) Increased vascular permeability ( Oedema

Question 34

Factors involved in the endometrial changes of progesterone?

Answer 34

IL-11, histamine, certain prostaglandins, TGFbeta (promotes angiogenesis

Question 35

hCG is produced by what

Answer 35

Placenta

Question 36

hCG acts on what receptors

Answer 36

LH receptors

Question 37

Purpose of hCG?

Answer 37

Acts like a gonadotrophin in the absence of LH/FSH (due to prolactin inhibition)

Question 38

what does a urine pregnancy test test

Answer 38

hCG

Question 39

How many weeks does it take for hCG in plasma to peak during prenancy

Answer 39

about 8

Question 40

What is the dominant reproductive hormone throughout pregnancy

Answer 40

Progesterone

Question 41

where is PROGESTERONE AND OESTROGEN PRODUCTION in the FIRST 40 DAYS

Answer 41

- Produced by CORPUS LUTEUM (follicle that released the ovum)

Question 42

what stimulates PROGESTERONE AND OESTROGEN PRODUCTION in the FIRST 40 DAYS

Answer 42

 Stimulated by hCG (produced by trophoblasts) and acts on LH receptors - Essential for developing fetoplacental unit

Question 43

What cells produce hCG during pregnancy

Answer 43

trophoblasts

Question 44

From day 40 of pregnancy, where are oestrogens sourced from

Answer 44

Placenta

Question 45

DHEAS converted by X into oestrogens

Answer 45

Placenta

Question 46

What produces DHEAS

Answer 46

mother and foetus

Question 47

What maternal hormones increase during pregnancy (6)

Answer 47

- ACTH- can cause erroneous Cushing’s diagnosis - Adrenal steroids - Prolactin If someone has a prolactinoma then you have to use MRI to track prolactinoma size, OR can measure visual fields in each trimester - IGF1 (stimulated by placental GH-variant) - Iodothyronines (increased demand for thyroid hormones in pregnancy) - PTH related peptides

Question 48

What maternal hormones decrease during pregnancy (6)

Answer 48

- Gonadotrophins - Pituitary GH - TSH

Question 49

During pregnancy this hormone goes up or down: ACTH

Answer 49

Increases

Question 50

During pregnancy this hormone goes up or down: Prolactin

Answer 50

Increases

Question 51

During pregnancy this hormone goes up or down: adrenal steroids

Answer 51

Increases

Question 52

During pregnancy this hormone goes up or down: IGF1

Answer 52

Increases

Question 53

During pregnancy this hormone goes up or down: Iodothyronines

Answer 53

Increases

Question 54

During pregnancy this hormone goes up or down: PTH related peptides

Answer 54

Increases

Question 55

During pregnancy this hormone goes up or down: gonadotrophin

Answer 55

Decreases

Question 56

During pregnancy this hormone goes up or down: Pituitary GH

Answer 56

Decreases

Question 57

During pregnancy this hormone goes up or down: TSH

Answer 57

Decreases

Question 58

What hormones are involved in parturition and ions (4)

Answer 58

calcium, driven partly by oestrogen and inhibited by progesterone, Oxytoxin

Question 59

What hormone inhibits parturition

Answer 59

Progesterone

Question 60

What drives parturition (3)

Answer 60

Oxytocin, oestrogen and calcium entry

Question 61

What hormone promotes milk ejaculation

Answer 61

Oxytocin

Question 62

What hormone promotes milk syntheiss

Answer 62

prolactin