Physiology of Pregnancy Flashcards
Describe how the CO changes in pregnancy?
Increases from 6 weeks on
In the first trimester what structures is responsible for producing progesterone?
Corpus luteum
When does the corpus luteum degenerate?
1st half of the second trimester
When does the placenta take over the production of pregnancy?
1st half of the second trimester
What happens to oestrogen levels during pregnancy?
Rise throughout the whole 9 months
What hormone causes growth of the ductile system of the breast?
Oestrogen
Which cells penetrate the endometrium during implantation?
Trophoblast
By what day does the blastocyst become buried in the uterine lining?
Day 12
Is the partial pressure of Carbon dioxide elevated or lowered in fetal blood?
Elevated
Is the fetal haemoglobin curve shifted to the right or left? What does this mean?
Left. It can bind oxygen at a much lower partial pressure
List three ways in which the oxygen supply to the fetus is facilitated?
Fetal Hb - higher affinity for Oxygen
Higher Hb concentration in fetal blood
Bohr effect (Fetal Hb can carry more oxygen in low pC02 than in high pC02
How does water diffuse across the placenta?
Osmosis
How does glucose get into the fetus?
Simplified transport
What is the initial action of HCG?
Prevents breakdown of the corpus lutem
What does HCS do and when is it produced?
From week 5
Growth hormone like effects
Decreases insulin sensitivity in the mother
What hormone is responsible for the development of decidual cells?
Progesterone
What hormone is responsible for relaxation of the ligaments?
Oestrogen
What hormone is responsible for enlargement of the uterus?
Oestrogen
What happens to the CO in pregnancy?
Increases week 6 to week 24
Decreases in last 8 weeks due to vena cava compression
Increases 30% during labour
What happens to HR in pregnancy?
Increases
What happens to blood pressure in the second trimester?
Drops due to expansion of the uteroplacental circulation and decreased peripheral resistance
Describe what happens to the plasma volume in pregnancy?
Increases
What happens to erythropoiesis during pregnancy?
Increases
What happens to haemaglobin levels during pregnancy?
Decrease due to dilution
Give two reasons why lung function changes during pregnancy?
Progesterone
Effect of enlarging terus
What does progesterone do during pregnancy that effects the respiratory system?
Increases the CO2 sensitivity in the respiratory centres (causes a lowering of CO2 levels)
How does the respiratory system change in pregnancy?
RR increases
Tidal and minute volume increases
PC02 decreases
Vital capacity and P02 stay the same.
What is tidal volume?
The volume of air displaced in one breath
What is minute volume?
The volume of air inhaled or exhaled per minute
What is vital capacity?
The maximum amount of air a person can expel from the lungs after a maximum inhalation. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume
What happens to GFR in pregnancy?
Increases
What happens to renal plasma flow in pregnancy?
Increases
Which hormone causes development of the lobular alveolar system?
Progesterone
Which hormone stimulates milk production?
Prolactin
Which hormone is responsible for contraction of smooth muscle causing the milk let down reflex?
Oxytocin
Which hormone causes increased oxytocin receptors on the uterus?
Oestrogen
