Endocrinology 11 - Endocrinology of Pregnancy Flashcards
Where is seminal fluid from?
- Small contribution from epididymis or tesis
- Acessory sex glands - seminal vesicles, prostate, bulbourethral glands
Describe the process of capacitation of sperm
- Maturation and activation
- Loss of glycoprotein coat
- Change in surface membrane characteristics
- Develop whiplash movements of tail
- Achieved in the fallopian tube (oestrogen and Ca2+ dependent)
Describe the acrosome reaction
- Sperm binds to ZP3 (sperm receptor)
- Calcium influx into the sperm (stimulated by progesterone)
- Release of hyaluronidase and proteolytic enzymes from the acrosome
- Spermatozoon penetrates the zona pellucida
Describe the process of fertilisation
- Occurs within the fallopian tube
- Triggers cortical reaction
- Cortical granules release molecules which degrade zona pellucida (prevents further sperm binding)
- Haploid to diploid
Describe the development of conceptus
- Continues to divide as it moves to the uterus
- Recieves nutrients from uterine secretions
- Can last for 9-10 days
Describe the process of implantation
- Attachment phase (outer trophoblast cells contact uterine surface epithelium)
- Decidualisation phase (changes in underlying uterine stromal tissue)
- Requires progesterone domination in the presence of oestrogen
Describe the process of attachment phase
- Attachment of blastocyst to endometrial lining to trigger implantation
- Outer trophoblast cells contact uterine surface endothelium
- Leukaemia inhibitory factor from endometria secretory glands stimulates adhesion of blastocyst to endometrial cells
- Interleukin 11 from endometrial cells is released into uterine fluid
Describe the process of decidualistion
- Trophoblast migration into the endometrium and maternal spiral arteries
- CHanges in underlying uterine stromal tissue within a few hours of contact (progesterone domination + oestrogen presense)
- Endometrial changes
- Interleukin 11, histamine and prostagladins are involved
Describe progesterone and oestrogen production during pregnancy
- In the first 40 days, produced by the corpus luteum, which inhibits maternal LH and FSH
- From day 40, the placenta takes over production
Describe the physiological changes in maternal hormones
Increase in
- ACTH
- Adrenal steroids
- Prolactin (test visual fields in pregnant women)
- IGF1
- Iodothyronines (due to hCG)
- PTH related peptides
Decrease in
- Gonadotrophins
- Pituitary GH
- TSH
Describe the endocrine control of partruition
- Oestrogen, cortisol and oxytocin are the key hormones
- Oxytocin induces uterine contraction, cervical dilation and milk ejection
Describe the endocrine control of lactation
- Prolactin stimulates milk synthesis (adenohypophysis)
- Oxytocin stimulates milk ejection (neurohypophysis)
Which hormone becomes important in pregnancy?
hCG - human chorionic gonadotrophin
Which factors are involved in implnatation?
- IL11
- LIF (leukaemia inhibitory factor)
- Progesterone
Describe the hormone changes and effects during pregnancy
- hCG goes up initially to maintain the corpus leuteum, and then decreases when oestrogen and progesterone production is taken over by the placenta (human chorionic gonadotrophin)
- Human placental lactogen (metabolism and insulin resistance, so the nutrients go to the baby) increases
- Oestrogen and progesterone increase
