Pregnancy

Question 1

What blocks the spiral artery to a fetus?

Answer 1

Trophoblasts.

Question 2

What sort of nutrition do fetus’s rely on to receive nutrition?

Answer 2

Histotrophic nutrition - nutritional material accumulated in spaces between the maternal and fetal tissues, derived from the maternal endometrium and the uterine glands.

Question 3

4 functions of a placenta

Answer 3

Respiratory organ, nutrient transfer, excretion of fetal waste, hormone synthesis

Question 4

What regulates the growth and development of a fetus?

Answer 4

Gastrin, motilin, somatostatin

Question 5

What are trophoblasts?

Answer 5

Cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. Border between maternal blood and umbilical arteries/veins.

Question 6

What are the contents of amniotic fluid?

Answer 6

Urine, amniotic membrane secretions, fetal lung secretions, salivary secretions, fetal epithelial cells.

Question 7

When does a fetus develop insulin?

Answer 7

From 9-11 weeks

Question 8

Adaptations in fetal circulation?

Answer 8

Umbilical vein and artery, ductus venosus, foramen ovale, ductus arteriosus.

Question 9

What is a ductus venosus?

Answer 9

It shunts a portion of the left umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver.

Question 10

What is a foramen ovale?

Answer 10

Hole between right and left atria. Allows blood to bypasss pulmonary circulation.

Question 11

What is a ductus arteriosus?

Answer 11

Shunt connecting the pulmonary artery to the aorta, therefore blood can ignore the lungs (inactive).

Question 12

3 changes at delivery

Answer 12

Closure of the foramen ovale, ductus arteriosus and ductus venosus.

Question 13

Difference between type 1 and type 2 alveolar epithelial cells

Answer 13

Type 1 increase surfactant surface area, type 2 secrete surfactant

Question 14

Components of surfactant

Answer 14

70% phospholipids, 10% protein, 10% cholesterol

Question 15

Function of surfactant

Answer 15

Reduces the surface tension to prevent the alveoli collapsing. This increases compliance (lung can stretch more)

Question 16

Differences between HbF and HbA

Answer 16

HbF has a higher oxygen affinity than HbA. HbF has a higher Hb concentration than HbA. HbF has a lower sensitivity to DPG.

Question 17

What can delay duct closure

Answer 17

Prostaglandin E2 and prostacyclin

Question 18

What accelerate duct closures

Answer 18

Non-steroidal anti-inflammatory drugs

Question 19

What is a chorion?

Answer 19

Outermost membrane surrounding an embryo

Question 20

3 roles of oestrogen in pregnancy

Answer 20

Contributes to blood vessel dilatation, helps make blood vessels more elastic, makes mother insulin resistant (so more glucose available for fetus)

Question 21

Roles of progesterone

Answer 21

Maintains endometrium in implantation, suppresses immunological response to fetal antigens, role in parturition (act of giving birth), maintenance of pregnancy (inhibition of uterine contractility, to prevent cervix maturing)

Question 22

What hormone is used in pregnancy testing?

Answer 22

hcG

Question 23

What hormone measures fetal growth and well-being?

Answer 23

hPL

Question 24

Function of hcG

Answer 24

Produced by placenta after implantation. Maintenance and function of corpus luteum

Question 25

Function of hPL

Answer 25

Anti-insulin therefore increases glucose for transport to fetus. Role in fatty acid metabolism to provide energy for fetal nutrition.

Question 26

Role of leptin

Answer 26

Stimulates placental amino acid and fatty acid transport

Question 27

Difference between cytotrophoblast and syncytiotrophoblast

Answer 27

Cytotrophoblast is the inner layer of the trophoblast. Syncytiotrophoblast is the outer layer. Both cover the embryonic vascular wall.

Question 28

3 changes during pregnancy

Answer 28

Cardiac output increases and heart rate increases. Increase in renin-angiotensin system (increase in aldosterone). Increase in GFR and clearance of fetal waste. Increase in urinary frequency. Increase in oxygen consumption and tidal volume. Increase in coagulation cascade (prevent blood loss). Reduced muscle tone, therefore increase in heartburn and nutrient absorption.

Question 29

What is neonatal respiratory distress syndrome?

Answer 29

Babies born with surfactant deficient lungs. It increases work of breathing, decreases lung compliance so alveolar collapses.

Question 30

Why is the pressure on the right side of the heart higher in the fetus?

Answer 30

Hypoxic pulmonary vasoconstriction of arterioles due to the lungs being in a low oxygen environment. This increases resistance to blood flow and increases pressure in pulmonary arteries/atrium/ right ventricle.

Question 31

What increases resistance to blood flow and increases pressure in pulmonary arteries.

Answer 31

Hypoxic pulmonary vasoconstriction.

Question 32

What is the precursor to progesterone?

Answer 32

Pregenolone.

Question 33

Androstenedione is a precursor to what two hormones?

Answer 33

Estrone. Testosterone.

Question 34

What is the effect of progesterone and oestrogen on the pituitary gland?

Answer 34

It inhibits the pituitary gland from producing FSH and LH.