Endocrinology of Pregnancy Flashcards

1
Q

Where is tubular fluid reabsorbed and what controls this process?

A

Rete testis
Early epididymis
This is under the control of oestrogen

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2
Q

Where do you find oestrogen within the male reproductive tract?

A

Tubular fluid produced by sertoli cells

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3
Q

What stimulates the release of nutrients and other molecules (e.g. glycoproteins) into the epididymal fluid?

A

Androgens

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4
Q

What are the roles of these secreted nutrients and molecules?

A

Provide energy for the impending journey

Coat the surface of the spermatozoon (to protect them from the hostile environment)

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5
Q

Within which part of the male reproductive tract is fluid reabsorbed and secretory products put in?

A

Epididymis

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6
Q

Why is the concentration of sperm in the vas deferens higher than further down the reproductive tract?

A

Further down the reproductive tract, other fluids and secretory products are added thus diluting the sperm.

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7
Q

Why is there fibrinogen and fibrinolytic enzymes in the seminal fluid?

A

After ejaculation, the semen initially clots and then must be broken down

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8
Q

Describe the capabilities of the spermatozoa in the vas deferens.

A

Capable of limited movement

Limited capability to fertilise an ovum

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9
Q

Which steroid precursor tends to be provided by the mother for the foetus?

A

Pregnenolone

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10
Q

Which androgen is formed by the maternal and foetal adrenals?This is used as a precursor for oestrogen production.

A

Dehydroepiandrosterone Sulphate (DHEAS)

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11
Q

Which oestrogens are produced by the placenta using DHEAS from the mother and foetus?

A

Oestradiol

Oestrone

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12
Q

What is the main oestrogen of pregnancy? Describe how it is produced.

A

OESTRIOL
DHEAS from the foetal adrenals is conjugated in the foetal liver to form 16-alpha-hydroxy DHEAS
16-alpha-hydroxy DHEAS is then de-conjugated in the placenta and used to produce oestriol

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13
Q

What can be measured to gage the health of the foetus?

A

Oestriol: oestradiol + oestrone levels
Oestriol: total oestrogens

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14
Q

What biochemical change is required for contraction of the uterus during parturition?

A

Increase in intracellular calcium concentration

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15
Q

Describe how oestrogen increases the chance of contraction.

A

Oestrogen binds to oestrogen receptors and triggers the synthesis of prostaglandins within the endometrial cells.
Prostaglandins stimulate the release of calcium from intracellular stores.
So oestrogen tends to increase the chance of contraction

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16
Q

Describe how oxytocin increases the chance of contraction.

A

Oxytocin binds to its receptor on the endometrial cell and opens calcium channels, allowing calcium ions to move in from outside

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17
Q

Describe the effect of progesterone on this contraction process.

A

Progesterone keeps the effects of oestrogen under control
Progesterone inhibits oestrogen receptors
Progesterone inhibits the production of prostaglandins

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18
Q

What change occurs when the foetus reaches a particular size, which is crucial for contraction to take place?

A

There is a switch in steroid synthesis from progesterone synthesis to oestrogen synthesis
This leads to oestrogen dominance –> prostaglandin production –> calcium release from intracellular stores –> promotion of muscle contraction

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19
Q

What 2 hormones are involved in milk production and milk ejection?

A

Prolactin – milk production
Oxytocin – milk ejection
These both have a similar neuroendocrine reflex arc stimulated by suckling

20
Q

Contents of semen

A

Sperm
Seminal fluid
Leukocytes

21
Q

Where does most seminal fluid come from

A

Seminal vesicles
Prostate
Bulbourethral

22
Q

Role of capacitation

A

Achieve fertilising capacity of spermicide in female repro tract

23
Q

3 parts to capacitation

A

Loss of glycoprotein coat
Change in surface membrane characteristic
Whiplash movements of tail

24
Q

What is capacitation dependent of

A

Ca and oestrogen

25
Q

Upon what does acrosome reaction occur

A

Binding to ZP3 glycoprotein of follicle

26
Q

What does binding to ZP3 receptor stimulate

A

Ca influx

27
Q

What is Ca2+ influx dependent of in acrosome reaction

A

Progesterone

28
Q

What is effect of Ca influx in acrosome reaction

A

Release of hyaluronidase and proteolytic enzymes

Allows penetration of zone pellucida

29
Q

Where does fertilisation occur

A

Fallopian tube

30
Q

What does fertilisation trigger

A

Cortical reaction

31
Q

Purpose of cortical reaction

A

Prevents further entry of sperm as degrades the zone pelluicda mainly the ZP3 and ZP2 receptors

32
Q

Immediate development of conceptus

A

Can last up to 10 days but normally 3-4

Continues to divide all the way down to uterus

33
Q

How does developing conceptus receive nutrients

A

Uterine secretions

34
Q

Stages to implantation

A

Attachment

Decidualisation

35
Q

What happens in attachment stage

A

Outer trophoblast cells contact uterine surface epithelium

36
Q

What happens in decidualisation stage

A

Changes in underlying uterine stromal tissue

37
Q

What’s needed for decidualisation stage

A

Progesterone dominating oestrogen

38
Q

Important molecules in attachment of blastocyst

A

Leukaemia inhibitory factor

Interleukin 11

39
Q

What secretes LIF

A

Endometrial secretory glands and maybe blastocyst

40
Q

Role of LIF

A

Adhesion

41
Q

What secretes IL11

A

Endometrial cells for adhesion

42
Q

Main factor involved in decidualisation

A

IL11

43
Q

Changes in decidualisation

A

Glandular epithelial secretion
Glycogen accumulation in stromal cytoplasm
Growth of capillaries
Increased vascular permeability

44
Q

Production of oestrogen and progesterone in first 40 days of pregnancy

A

Corpus luteum

45
Q

What stimulates production of oestrogen and progesterone in first 40 days of pregnancy

A

hCG from trophoblasts acting on LH receptors

46
Q

Role of oestrogen and progesterone in pregnancy

A

Essential for developing fetoplacental unit

Inhibits maternal LH and FSH