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8.4 Pregnancy & Placenta — Test 1
Q1. The type of placenta found in humans is:✓ Haemochorial
Q2. In a haemochorial placenta, maternal blood is in direct contact with the:✓ Chorion (fetal trophoblast)
Q3. In the feto-placental unit, fetal adrenal steroids such as DHEA are inactivated mainly by:✓ Sulfation
Q4. In lactating mothers, which hormone provides a period of natural contraception?✓ Prolactin
Q5. A placenta in which the number of barriers between maternal and fetal blood is reduced to just two layers is the:✓ Haemochorial placenta
Q6. Synepitheliochorial (epitheliochorial-type) placentation is usually seen in:✓ Ruminants
Q7. Which of the following is a haemochorial organ?✓ Placenta
Q8. The endotheliochorial placenta, in which the chorion contacts maternal blood-vessel endothelium, is typical of:✓ Carnivores (e.g. dogs and cats)
Q9. Implantation of the human embryo occurs at which stage?✓ Blastocyst
Q10. The outer cell layer of the blastocyst that invades the endometrium and forms the fetal placenta is the:✓ Trophoblast
Q11. The hormone secreted by the trophoblast that maintains the corpus luteum in early pregnancy is:✓ Human chorionic gonadotropin (hCG)
Q12. The main functions of the placenta include:✓ Nutrient/gas exchange, waste removal and hormone secretion
8.4 Pregnancy & Placenta — Test 2
Q13. Gas exchange across the placenta occurs by:✓ Diffusion down concentration gradients
Q14. Fetal haemoglobin (HbF) is adapted to placental exchange because it:✓ Has a higher oxygen affinity than adult haemoglobin
Q15. After the first trimester, the main source of progesterone shifts from the corpus luteum to the:✓ Placenta
Q16. The window of implantation refers to:✓ The short period when the endometrium is receptive to the blastocyst
Q17. Ectopic pregnancy refers to implantation:✓ Outside the uterine cavity (most often in a fallopian tube)
Q18. The epitheliochorial placenta (with the most intervening layers) is found in:✓ Pigs and horses
Q19. The umbilical cord connects the fetus to the placenta and contains:✓ Two umbilical arteries and one umbilical vein
Q20. Decidualization is the process in which:✓ The endometrium transforms to support the implanting embryo
Q21. The placenta acts as a partial barrier but can still allow passage of:✓ Some drugs, alcohol, viruses and antibodies
Q22. Maternal IgG antibodies cross the placenta to provide the newborn with:✓ Passive immunity in early life
Q23. Overall, the placenta is best described as:✓ A temporary organ of exchange, protection and hormone production
Q24. The number of tissue layers separating fetal and maternal blood determines:✓ How efficiently substances are exchanged across the placenta