Endocrinology of pregnancy Flashcards
Which cells make testosterone
Leydig cells
How is oestrogen produced
from testosterone with aromatase enzyme
What is the action of oestrogen in the male reproductive tract
Oestrogen induces tubular fluid reabsorption
What is the action of androgens in the male reproductive tract
Androgens induce nutrient e.g fructose and glycoprotein secretion into epididymal fluid
Function of glycoprotein
Protects spermatazoa from hostile environments
What does a lack of absorption of oestrogen in makes result in
Hirsutism, acne
V. tall– as oestrogen causes epiphyseal plate closer
Osteoporosis
What 4 things might the semen consist of
Spermatazoa
Seminal fluid
Leucocyte
Possible viruses e.g hep B or HIV
Journey of fertilisation
Through vagina, cervix, uterus, at one of fallopian tubes, zygote travel down to endometrium
What proportion of sperm reach the ovum
1 in a million
Sperm travels how many times itself
100,000
Seminal fluid produced from
Mainly from accessory sex glands:
- Seminal vesicles
- Prostrate
- Bulbourethral glands
Small contribution from
=Epididymis/testis
Capacitation of sperm
-occurs where
Sequence of events that occur to sperm
In ionic and proteolytic environment of the Fallopian tube
- Loss of glycoprotein oat
- Change in surface membrane characteristics
- Develop whiplash movmement of tail
What is the capacitation of sperm dependent on
Oestrogen and Ca2+
Sperm binds to what receptor
ZP3
What happens after sperm binds to ZP3
Influx of Ca2+ into sperm
Influx of Ca2+ influx stimulated by
Progesterone
Progesterone
- released by
- What phase of the menstrual cycle is this high in
What enzymes are released from acrosome
Result of this
- From corpus luteum
- Luteal phase
- Proteolytic enzymes and hyaluronidase
- Spermatozoon penetrates the Zona Pellucida
What is a first polar body in an acrosome reaction
Chromosome divide evenly
23:23
but not evenly with cytoplasm eventually undergoes apoptosis
Fertilisation occurs where
What reaction does this trigger why is this important
Fallopian tubes
Cortical reaction
- cortical granules release molecules which degrade Zona Pellucida
- Prevents further sperm binding as there are no more receptors
What happens after fertilisation at the fallopian tube
How long does this take
Continues to divide as it moves down Fallopian tube to uterus
3-4days
What does the zygote receive nutrients from
How long does this take
Uterine secretions
9-10 days
Pregnancy releases what hormone
From which part is this hormone released
Function of this hormone
hCG
hCG is released from the placenta
Maintains the corpus luteum
-acts on LH receptor
What cells of the blastocyst form the placenta
Which cells form the embyro
Trophoblast
Inner cell mass form embryo
What are 3 growth factors that are important for implantation
LIF. -Leukaemia Inhibition factor
IL11
Progesterone
Implantation 2 phases
Attachment phase
Decidualisation phase
Describe what happens at the attachment phase
Outer trophoblast cells contact uterine surface epithelium
Describe what happens in decidualisation phase
Changes in underlying uterine stromal tissue – within a few hours
What does implantation require
Requires progesterone domination in the presence of oestrogen
Where is LIF secreted from
Function
Endometrial secretory glands &blastocyst
Stimulates adhesion of blastocyst to
Where is LIF secreted from
Function
Endometrial secretory glands &blastocyst
Stimulates adhesion of blastocyst t
