2. physiological changes in pregnancy Flashcards
Post-fertilisation, what enzyme does the blastocyst produce and what structure produces it?
What is the function of this enzyme?
Give a clinical use of this enzyme.
Which symptom of pregnancy does this enzyme cause?
- β-hCG (beta- human chorionic gonadotropin), it is produced by the trophoblast of the blastocyst.
- B-hCG continues to support the corpus luteum after fertilisation so it will continue to produce progesterone. - The continued production of progesterone ensures that the uterus lining is getting sustained for the blastocyst to attach itself to.
- This enzyme can be used for pregnancy testing as it is detectable 10 days after fertilisation.
- Morning sickness.
When does the placenta take over oestrogen and beta-hCG production?
10-12 weeks.
Low levels of ______ hormone suggest an ectopic pregnancy.
beta-hCG.
Explain the role of progesterone in miscarraiges.
No progesterone = endometrium cant develop and so will eventually shed along with the developing embryp.
Which 4 hormones are produced by the placenta?
Progesterone.
Oestrogen.
beta-hCG.
Human placental lactogen.
Which three areas of the body/physiology does progesterone affect?
Uterus, breast and homeostasis.
Why might women suffering from asthma find their asthmatic symptoms are improved during pregnancy?
Progesterone will act as a smooth muscle relaxant and so will relax (dilate) the smooth muscles of the bronchi.
Give two examples of how progesterone plays a role in homeostasis during pregnancy.
“Think of breathing and urine”.
- increased respiratory centre hypersensitivity due to increased sensitivity of the respiratory receptors to CO2.
- increased sodium reabsorption through increased activity of renin system.
Give two examples of how progesterone affects breast tissue during pregnancy.
- increases lobule development.
- inhibits milk production.
Give 4 examples of how oestrogen affects the uterus during pregnancy.
- allows myometrium to grow.
- connexin insertion.
- oxytocin receptor insertion into myometrium which prepares uterus for the contractile element required for labour.
- Prostaglandin production which is important for the softening of the cervix.
How does oestrogen affect the breast tissue?
- contributes to breast duct development but it inhibits milk production.
Which intermediate, required for the synthesis of oestrogen, is not present in the placenta?
DHEA.
How does the placenta synthesis oestrogen?
- the placenta will release CRH.
- CRH will act on the baby’s anterior pituitary, triggering it to produce adrenocorticotropic hormone (ACTH).
- ACTH will act on the adrenal cortex and trigger it to produce cortisol.
- this cortisol can be used to make DHEA.
- the DHEA is transported to the mother’s placenta, where it can be used to synthesis oestrogen.
Which hormone in pregnancy is responsible for uterus smooth muscle relaxation (to prevent fetal expulsion) and the formation of a cervical plug?
Progesterone.
What is the probable pathway via which lung maturation occurs in the foetus?
- placenta will release CRH, which will also act on mother’s anterior pituitary.
- anterior pituitary will release ACTH.
- ACTH will act on mother’s adrenal cortex to produce cortisol.
- this cortisol is likely involved in the foetuses lung maturation.
Give three examples of how human placental lactogen affects the mother.
- increased lipid breakdown and the release of free fatty acids.
- breast development.
- insulin resistance resulting in decreased glucose utilisation therefore increased levels of blood glucose.
Give two examples of how human placental lactogen affects the foetus.
- the increased blood glucose from the mother can be used to promote growth in the foetus.
What causes the symptoms of FUNCTIONAL anaemia in pregnant women?
- although the blood volume increases due to increase in plasma levels, the RBC levels don’t increase enough with it.
- therefore, this is due to hemodilation.
The lack of which two substances causes pathological anaemia in pregnant women?
- iron and folic acid.
Describe the physiological changes of “clotting” that take place in pregnancy.
- there is a decrease in anti-thrombotic factors resulting in a higher proportion of pro-thrombotic factors.
How does the foetus affect the mother’s heart?
Due to the growing abdominal mass, the heart can get displaced and will move outwards and upwards.
What is the equation for blood pressure?
BP = CO x SVR.
What is the equation for cardiac output?
CO = SV x HR.
sv - stroke volume.
What is the stroke volume?
The amount of blood pumped out after each heartbeat.
