At which point in the pregnancy can a woman first feel fetal movement (quickening)?

Correct Answer: C

Rationale: The correct answer is C (20 weeks) because quickening, the first perception of fetal movement by the mother, typically occurs around this time. At 20 weeks, the fetus is large enough for its movements to be noticeable to the mother. Before 20 weeks, the fetus is too small and the movements are not strong enough to be felt. Choices A, B, and D are incorrect because they are too early in the pregnancy for the mother to feel fetal movement. By 20 weeks, the fetus has developed enough for the mother to perceive its movements, making option C the correct answer.

Correct Answer: C

Rationale: In this question, the correct answer is C) Fertilized ovum. The trophoblast is the outer layer of cells in a fertilized ovum that plays a crucial role in implantation and the formation of the placenta during fetal development. Option A and B are marked as "None," which is incorrect as they do not provide any meaningful information related to the trophoblast. Option D is also incorrect as it does not describe the specific role or function of the trophoblast in fetal development. Educationally, understanding the structure and function of the trophoblast is essential in comprehending the early stages of fetal development. It helps students grasp how the embryo implants in the uterus and establishes the necessary connections for nutrient and waste exchange with the mother through the placenta. This knowledge is fundamental in embryology and obstetrics and provides a foundational understanding of prenatal development.

Correct Answer: B

Rationale: In fetal development, the umbilical cord plays a crucial role in providing oxygen and nutrients to the developing fetus from the mother. The correct answer is B) Wharton's jelly. Wharton's jelly is a gelatinous substance within the umbilical cord that surrounds and protects the blood vessels. It acts as a cushion, preventing compression of the blood vessels and ensuring uninterrupted blood flow between the placenta and the fetus. Option A) None is incorrect because there is indeed a protective substance present in the umbilical cord, which is Wharton's jelly. Option C) and D) are duplicates and are incorrect. Educationally, understanding the components of the umbilical cord is essential for healthcare professionals working in obstetrics, midwifery, and neonatal care. Knowing the role of Wharton's jelly in protecting the blood vessels helps ensure proper fetal development and can guide clinical decision-making during pregnancy and childbirth. This knowledge is crucial for providing optimal care and monitoring fetal well-being during pregnancy.

Correct Answer: D

Rationale: In fetal circulation, the ductus venosus is a crucial shunt that allows oxygenated blood to bypass the liver and flow directly into the inferior vena cava. This is essential for ensuring that the developing fetus receives oxygenated blood efficiently. Option A, connecting the pulmonary artery and the aorta, describes the ductus arteriosus, not the ductus venosus. Options B and C are incorrect as they do not pertain to the ductus venosus's function in fetal circulation. Educationally, understanding fetal circulation is important in comprehending how oxygen and nutrients are delivered to the developing fetus and how waste is removed. This knowledge is fundamental in obstetrics, pediatrics, and understanding congenital heart defects. It also highlights the unique adaptations the fetal circulatory system undergoes to support the growing fetus in utero.

Correct Answer: B

Rationale: The correct answer is B) Sixth week following the last menstrual period. This is because the fetal heartbeat typically becomes visible on ultrasound around the fifth to sixth week of pregnancy. This milestone is important as it indicates the presence of a developing embryo with a beating heart, signifying a crucial stage in fetal development. Option A) Fourth week following the last menstrual period is incorrect because it is too early for the fetal heartbeat to be visible at this stage. The heart begins to form around the third week, but it takes a few more weeks for it to develop and become detectable on ultrasound. Option C) Ninth week following the last menstrual period is also incorrect as the fetal heartbeat should be visible before this time frame. Waiting until the ninth week to see the heartbeat could indicate a potential issue with the pregnancy that needs further evaluation. Option D) Twelfth week following the last menstrual period is too late for the fetal heartbeat to be first visible. By the twelfth week, the heartbeat should not only be visible but also audible using a Doppler device, so waiting until this point to confirm the heartbeat is beyond the typical timeline for ultrasound detection. Understanding the timeline of fetal development milestones, such as when the heartbeat becomes visible, is crucial for healthcare providers and expectant parents to monitor the progress of the pregnancy and ensure the well-being of the developing fetus. Early detection of the fetal heartbeat can provide reassurance and important information about the pregnancy's viability.