Nokea
What are the factors that explain why a woman is fertile only a few days out of each monthly cycle?
- A. (1) Sperm usually cannot survive in the female reproductive tract for more than a few days, (2) an ovum must unite with a sperm during the first 24 hours after ovulation, before it reaches the uterus, so it will be ready for implantation, and (3) the cyclical mechanisms of female reproductive function limit the release of ova.
- B. (1) Sperm usually cannot survive in the female reproductive tract for more than 24 hours, (2) an ovum must unite with a sperm within the first 12 hours after ovulation, before it reaches the uterus, so it will be ready for implantation, and (3) the cyclical mechanisms of female reproductive function limit the release of ova.
- C. (1) Sperm usually cannot survive in the female reproductive tract for more than a few days, (2) an ovum must unite with a sperm within 12 hours after ovulation, before it reaches the uterus, so it will be ready for implantation, and (3) the cyclical mechanisms of female reproductive function limit the release of ova.
- D. (1) Sperm usually cannot survive in the female reproductive tract for more than 12 hours, (2) an ovum must unite with a sperm immediately after ovulation, before it reaches the uterus, so it will be ready for implantation, and (3) the cyclical mechanisms of female reproductive function limit the release of ova.
Correct Answer: A
Rationale: The correct factors explaining fertility include sperm survival, timing of fertilization, and cyclic release of ova.
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Which of the following is the least predictable method of determining ovulation time?
- A. The measurement of LH in the urine
- B. The length of previous cycles
- C. The change in basal body temperature
- D. All of the above methods are equally accurate in determining ovulation time.
Correct Answer: B
Rationale: The length of previous cycles is less predictable compared to other methods.
The innermost layer of the wall of the uterus is the stratum:
- A. Myometrium
- B. Compactum
- C. Spongiosum
- D. Basale
Correct Answer: B
Rationale: The innermost layer of the uterine wall is the stratum compactum.
The phase of the menstrual cycle that occurs between the expulsion of the ovum from the ovary and the onset of menses is the _____ phase.
- A. Proliferative
- B. Follicular
- C. Luteal
- D. Estrogenic
Correct Answer: C
Rationale: The luteal phase occurs after ovulation and before the onset of menses.
What does FSH primarily act to stimulate?
- A. Development of the uterine endometrium
- B. Release of the mature ovum
- C. Maturation of the ovarian follicle
- D. Development of the ovary
Correct Answer: C
Rationale: FSH primarily acts to stimulate the maturation of the ovarian follicle. FSH facilitates the growth and development of the follicle in the ovary, leading to the release of a mature ovum during ovulation. This process is essential for successful reproduction. Choice A is incorrect because the development of the uterine endometrium is primarily influenced by estrogen and progesterone. Choice B is incorrect as the release of the mature ovum is triggered by the surge in luteinizing hormone (LH), not FSH. Choice D is incorrect as the development of the ovary itself is not a direct function of FSH.
A 5-day-old infant male has an abnormally large head. A CT scan examination reveals enlarged lateral and third ventricles but a normal-size fourth ventricle. Which of the following conditions is likely to cause this presentation?
- A. Holoprosencephaly
- B. Disorder of prosencephalon
- C. Stenosis of aqueduct of Sylvia
- D. Meningitis with blockage of arachnoid villi
Correct Answer: C
Rationale: The correct answer is C: Stenosis of aqueduct of Sylvia. This condition causes obstruction in the Sylvian aqueduct, leading to hydrocephalus with enlarged lateral and third ventricles but a normal fourth ventricle. Holoprosencephaly (A) is a midline defect, not specific to ventricle enlargement. Disorder of prosencephalon (B) is too broad and doesn't specifically address ventricle enlargement. Meningitis with blockage of arachnoid villi (D) is typically associated with communicating hydrocephalus, not specific to the aqueductal stenosis pattern seen in this case.