Fetal Gas Exchange

Question 1

On what day does embryonic implantation occur?

Answer 1

Day 7

Question 2

By what day does embryonic implantation generally conclude?

Answer 2

Day 14

Question 3

What is the rate of success for implantation?

Answer 3

Roughly 30%

Question 4

What happens if implantation fails?

Answer 4

Blastocyte is shed with endometrium lining

Question 5

Where does implantation typically occur?

Answer 5

Posterior wall of the uterus

Question 6

What is it called when a blastocyte implants outside of the uterus?

Answer 6

ectopic pregnancy

Question 7

What is placenta previa?

Answer 7

placenta previa is a condition in which the placenta forms in an abnormal place which could potentially block off the cervix or make delivery more difficult

Question 8

T/F: the placentas genetic material is identical to the fetus

Answer 8

True

Question 9

T/F: the umbilical cord is considered to be part of the fetus

Answer 9

False. The umbilical cord is considered to be part of the placenta

Question 10

When does the placenta completely form?

Answer 10

14-16 weeks gestation

Question 11

Where does fetal gas exchange occur?

Answer 11

chorionic villi

Question 12

Describe the arrangement of blood vessels in the umbilical cord

Answer 12

1. There is 1 umbilical vein carrying oxygenated blood to the fetus
2. There are 2 umbilical arteries carrying deoxygenated blood away from the fetus

Question 13

What is the key difference between fetal hemoglobin and adult hemoglobin?

Answer 13

Fetal hemoglobin does not have 2,3 BPG

Question 14

What is the effect of the lack of 2,3 BPG on the oxyhemoglobin disassociation curve?

Answer 14

it causes a left shift in the curve resulting in fetal hemoglobin having a higher affinity for oxygen

Question 15

Describe the “double bohr” effect on fetal gas exchange

Answer 15

1. High concentrations of CO2 from the fetal blood diffuse into the maternal blood resulting in a decreased affinity for oxygen in the maternal blood
2. The decrease in CO2 in the fetal blood at the chorionic villi results in the blood becoming alkaline and having a higher affinity for O2

Question 16

What is the general purpose of the placenta

Answer 16

The placenta provides vital functions for metabolic, renal, hepatic, immunologic and gas exchange

Question 17

When is the umbilical cord formed?

Answer 17

formation begins in the 3rd week of gestation

Question 18

What are complications associated with the umbilical cord?

Answer 18

1. Single umbilical artery
2. Nuchal Cord
3. umbilical cord prolapse

Question 19

What are the implications associated with single umbilical arteries?

Answer 19

1. associated with organ abnormalities
2. Renal, cardiovascular, gastrointestinal and central nervous system abnormalities

Question 20

Describe what nuchal cord is and how common it is

Answer 20

1. Occurs in about 30% of births
2. Cord becomes wrapped around babys neck and body

Question 21

Why is a prolapsed umbilical cord considered emergent?

Answer 21

1. Cord appearing first during birth can result in decreased blood flow to the fetus

Question 22

What could be an indication of umbilical cord prolapse?

Answer 22

fetal bradycardia