Which of the following conditions must be met for fertilization to occur? Select all that apply
Sperm must be deposited in the uterus during coitus.
Sperm must undergo capacitation in the female reproductive tract.
The ovum must be viable for at least 48 hours after ovulation.
Sperm motility must be sufficient to navigate the cervix and uterus.
Cervical mucus must be thin and less viscous.
Correct Answer : B,D,E
Fertilization is the union of a mature sperm and ovum resulting in a zygote. Successful fertilization depends on sperm capacitation, which is the biochemical modification of sperm in the female reproductive tract that enables penetration of the ovum. Sperm must exhibit adequate motility to traverse the cervical mucus, uterus, and fallopian tubes. The cervical mucus undergoes cyclical changes, becoming thin and less viscous during ovulation to facilitate sperm passage. The ovum’s viability is typically 12 to 24 hours post-ovulation, not 48 hours, and sperm are usually deposited in the vagina, not directly in the uterus.
Rationale for correct answers
B. Capacitation involves the removal of glycoproteins and seminal plasma proteins from sperm, which enables acrosomal reaction necessary for ovum penetration.
D. Sperm motility is essential for migration through the cervix, uterus, and fallopian tubes, overcoming the challenges of the female reproductive environment.
E. Thin, less viscous cervical mucus during ovulation reduces resistance, allowing sperm to swim effectively toward the ovum.
Rationale for incorrect answers
A. Sperm are normally deposited in the vagina during coitus, not directly in the uterus; uterine deposition is not a prerequisite for fertilization.
C. The ovum remains viable for approximately 12 to 24 hours after ovulation; viability for 48 hours is incorrect, as the fertilization window is shorter.
Take home points
- Capacitation is necessary to activate sperm for fertilization.
- Adequate sperm motility is crucial for successful sperm migration.
- Cervical mucus consistency changes to facilitate sperm passage during ovulation.
- Ovum viability after ovulation is limited to about 12 to 24 hours.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Amniotic fluid volume is tightly regulated and serves multiple functions, including cushioning the fetus, facilitating movement, and allowing lung development. In the third trimester, the majority of amniotic fluid is produced by fetal urine excreted into the amniotic cavity and lung fluid secreted by the fetal respiratory tract. Normal amniotic fluid volume ranges between 500 to 1000 mL at term. Fluid turnover involves swallowing and absorption by the fetus as well as contributions from membranes and maternal sources.
Rationale for correct answers
C. Fetal urine production significantly increases in the third trimester, contributing the bulk of amniotic fluid volume. Additionally, fetal lungs secrete fluid that mixes with the amniotic fluid, ensuring appropriate volume and composition. This combined secretion accounts for the majority of amniotic fluid after 28 weeks gestation.
Rationale for incorrect answers
A. Diffusion of fluid from maternal blood across the placental membranes contributes minimally to amniotic fluid volume, especially in the third trimester, as fetal urine becomes predominant.
B. Secretions from the fetal gastrointestinal tract do not contribute significantly to amniotic fluid volume; rather, swallowed amniotic fluid is absorbed, not secreted into the cavity.
D. Transudation from fetal skin is significant only early in gestation before keratinization, which is complete by about 20 weeks, greatly reducing this source by the third trimester.
Take home points
- The majority of third trimester amniotic fluid is produced by fetal urine and lung fluid secretions.
- Amniotic fluid volume ranges from 500 to 1000 mL near term and is critical for fetal development.
- Maternal diffusion and fetal skin transudation contribute minimally after mid-gestation.
- Fetal swallowing and absorption regulate amniotic fluid volume alongside production.
Correct Answer is A
Explanation
The umbilical cord typically contains three vessels: two umbilical arteries and one umbilical vein. The arteries carry deoxygenated blood and waste products from the fetus to the placenta, while the single vein returns oxygenated, nutrient-rich blood from the placenta to the fetus. The normal number of vessels ensures adequate fetal circulation and nutrient exchange. Variations such as a single umbilical artery occur in about 1% of pregnancies and can be associated with congenital anomalies but are not the norm.
Rationale for correct answers
A. The presence of two arteries and one vein is the normal anatomy of the umbilical cord. The two arteries arise from the fetal internal iliac arteries and transport deoxygenated blood to the placenta, while the single vein carries oxygenated blood back to the fetus.
Rationale for incorrect answers
B. One artery and one vein represent an abnormal finding known as a single umbilical artery, which may be associated with congenital anomalies or fetal growth restriction and is not the normal anatomy.
C. Two veins and one artery is not a typical umbilical cord configuration; the umbilical cord normally has only one vein.
D. Three arteries and no veins is anatomically incorrect and incompatible with fetal survival due to lack of oxygenated blood return.
Take home points
- Normal umbilical cord anatomy includes two arteries and one vein.
- Two arteries carry deoxygenated blood from fetus to placenta; one vein returns oxygenated blood.
- Single umbilical artery is an abnormal variant with possible fetal risks.
- Proper vessel number is critical for effective fetal circulation and nutrient exchange.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.