Nokea
Which immunoglobulin is the only one that crosses the placenta during pregnancy?
- A. IgG
- B. IgA
- C. IgM
- D. IgD
Correct Answer: A
Rationale: The correct answer is A: IgG. IgG is the only immunoglobulin that can cross the placenta due to its small size and ability to bind to the neonatal Fc receptor. This transfer provides passive immunity to the fetus, protecting it from infections. IgA primarily functions in mucosal immunity and is found in secretions like breast milk. IgM is too large to cross the placenta and is mainly produced in response to acute infections. IgD is primarily found on the surface of B cells and functions in the activation of these cells.
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The nurse is explaining the process of cell division during the preembryonic period to a group of nursing students. Which statement best describes the characteristics of the morula?
- A. Fertilized ovum before mitosis begins
- B. Double layer of cells that becomes the placenta
- C. Flattened, disk-shaped layer of cells within a fluid-filled sphere
- D. Solid ball composed of the first cells formed after fertilization
Correct Answer: D
Rationale: The correct answer is D because a morula is a solid ball composed of the first cells formed after fertilization. During the preembryonic period, the zygote undergoes several rounds of cell division to form a morula, which is a compact cluster of cells. A: is incorrect as a fertilized ovum is a zygote, not a morula. B: is incorrect as the double layer of cells that becomes the placenta is the bilaminar germ disc, not the morula. C: is incorrect as a flattened, disk-shaped layer of cells within a fluid-filled sphere describes the blastocyst, not the morula. Thus, the characteristics of a morula being a solid ball composed of the first cells formed after fertilization make option D the correct choice.
At 16 weeks of gestation a pregnant person states, 'The most dangerous time is the first 3 months, so I shouldn’t have to worry from now on about any dangers to the baby.' What is the nurse's most appropriate response?
- A. There are teratogens with the potential to harm your baby at any time during the pregnancy.
- B. We really won’t be able to say for sure before you have an ultrasound.
- C. You are correct. You are past the critical point.
- D. You don’t seem very concerned about your baby’s welfare.
Correct Answer: A
Rationale: The correct answer is A because teratogens, substances that can harm the developing fetus, can have negative effects on the baby at any point during pregnancy, not just in the first trimester. The nurse's response should educate the pregnant person about the ongoing risks and the importance of avoiding harmful substances throughout pregnancy.
Option B is incorrect because an ultrasound is not used to assess the risk of teratogens. Option C is incorrect as it provides incorrect information that the risk is past, which is not true. Option D is incorrect as it is judgmental and does not address the pregnant person's misconception about the risks throughout pregnancy.
The nurse is explaining fetal circulation to a group of nursing students. Which information should be included in the teaching session? (Select all that apply.)
- A. After birth the ductus venosus remains open, but the other shunts close
- B. The foramen ovale shunts blood from the right atrium to the left atrium.
- C. The ductus venosus shunts blood from the liver to the inferior vena cava
- D. The ductus venosus shunts blood from the liver to the inferior vena cav
Correct Answer: C
Rationale: The correct answer is C: The ductus venosus shunts blood from the liver to the inferior vena cava. During fetal circulation, the ductus venosus allows oxygenated blood from the placenta to bypass the liver and flow directly into the inferior vena cava. This is important for fetal circulation as the liver is not fully functional in the fetus. After birth, the ductus venosus closes as the liver becomes fully operational.
Rationale for incorrect choices:
A: After birth, the ductus venosus closes, not remains open.
B: The foramen ovale shunts blood from the right atrium to the left atrium, not related to the ductus venosus.
D: This choice is a repetition of the correct information but incorrectly states the destination of the shunted blood.
A 37-year-old patient is being seen for her first OB appointment after having a positive pregnancy test at home. She thinks she is about 6 weeks pregnant. She and her husband have been trying to conceive for 7 years, and she has a history of three spontaneous abortions. What antepartum testing do you anticipate the provider ordering at today’s visit?
- A. a vaginal ultrasound to confirm gestation age, due date, and pregnancy viability
- B. maternal assay blood tests to screen for genetic and chromosomal disorders
- C. a nuchal translucency ultrasound
- D. an integrated screen blood test
Correct Answer: A
Rationale: The correct answer is A: a vaginal ultrasound to confirm gestation age, due date, and pregnancy viability. At the first OB appointment, confirming gestational age and viability is crucial, especially for a patient with a history of spontaneous abortions. This ultrasound will help determine the accurate due date and assess the viability of the pregnancy. Maternal assay blood tests for genetic and chromosomal disorders (choice B) are usually done later in the pregnancy, around 10-13 weeks. Nuchal translucency ultrasound (choice C) and integrated screen blood test (choice D) are typically done between 11-14 weeks and are not usually ordered at the first OB appointment.
What is the purpose of chorionic villus sampling (CVS) in the first trimester?
- A. to measure the amount of amniotic fluid
- B. to confirm pregnancy
- C. to assess the risk of chromosomal abnormalities in the fetus
- D. to assess for potential maternal infection
Correct Answer: C
Rationale: Rationale: CVS is done in the first trimester to assess the risk of chromosomal abnormalities in the fetus by obtaining a sample of cells from the placenta. This allows for genetic testing to detect conditions such as Down syndrome. Other choices are incorrect as CVS is not used to measure amniotic fluid quantity (A), confirm pregnancy (B), or assess maternal infection (D).