Endocrinology of Pregnancy Flashcards
Which role do oestrogens and androgens play in the efferent ducts and the epididymis of the male reproductive tract?
Oestrogens induce tubular fluid reabsorbtion –> to make a concentrate
Androgens induce nutrient secretion into the seminal fluid (for journey) in the epididymis
Which glands make the seminal fluid?
Mainly from accessory sex glands
- prostate gland
- seminal vesicles
- bulbourethral gland
–> Only little contribution of Epididymis/testis –> spermatozoa
Which changes does the spermatozoa undergo in the female reproductive tract?
What is the significance?
It undergoes changes that enable spermatogenesis:
- Capacitation
- loss of glycoprotein coat
- changes in surface membrane characteristics
- “whiplash” movement of tail –> peitschenartig
What is capacitation?
Changes that make spermatozoa able to fertilise ovum including
- Loss of glycoprotein ‘coat’
- Change in surface membrane characteristics
- Develop whiplash movements of tail
Where does capacitation take palce?
in ionic & proteolytic environment of the Fallopian tube
Which factors are needed for capacitation?
It is
- Ca2+ and
- oestrogen dependant –> needs female reproductive tract
What is the acrosome reaction?
The reaction, the acrosome of a sperm undergoes to penetrate the hard shell of the ovum (the Zona Pellucida)
What happens during the acrosome reaction?
- Initiation: Sperm binds to sperm receptor (ZP3)
- Ca2+ influx into sperm (progesterone mediated)
- Induces a release of hyaluronidase + proteolytic enzymes to
- penetrate the Zona Pellucida
Which hormone is needed for the acrosome reaction?
Ca2+ influx into sperm (neede for release of protein) is progesterone dependant
What happens when an ovum gets fertilised?
It changes its Zona Pellucida to prevent further binding + fertilisation by sperm (as no receptors are there anymore)
Mediated by a release of cortical granules (like ZP2 & 3)
What is the Conceptus?
It is the derivate of zygote –> everything that derivates from zygote (including embryus and extracellular (placental) parts)
How long does the free living phase of the conceptus last?
What is is supplied by during that time?
Can last up to 9-10 days (3-4 days until reached uterus)
–> Receives nutrients from uterine secretions
Explain the different phases of the blastocyte in the uterus
- Attachment phase
- outer trophoblast cells contact uterine surface epithelium
- Decidulisation phase
- changes in underlying uterine stromal tissue (within a few hours)
Which hormonal and non-hormonal factors influence implantation of the blastocyte in the uterus?
- LIF = Leukaemia inhibitory factor
- secreted by endometrial secretory glands
- stimulates adhesion of blastocyst to endometrial cells
- IL 11
- also from endometrial cells is released into uterine fluid, and may be involved
- Required progesterone dominance in presence of oestrogen
Explain the effects of progesterone on the endometrium in Decidualisation
Decidualisation= changes of endometrium after adhesion of blastocyst
Progesterone influences
- glandular epithelial secretion
- glycogen accumulation in connective tissue cells (stroma cells)
- increase vascularisation –> growth of capillaries
- increase permeability –> oedema