Nokea
Neonates that are kept in 100% oxygen incubators for several days become blind when they are removed from the incubator, a condition referred to as retrolental fibroplasia. What is the explanation for the loss of sight?
- A. The high concentration of oxygen stimulates the growth of fibrous tissue into the retina
- B. The high concentration of oxygen causes rupture of blood vessels in the retina, resulting in fibrous infiltration of the vitreous humor
- C. The high concentration of oxygen retards the growth of blood vessels in the retina, but when the oxygen therapy is stopped, the fall in oxygen concentration stimulates an overgrowth of blood vessels in the retina and vitreous humor, which later become densely fibrous and block the light from the pupil
- D. The high concentration of oxygen destroys the retinal neurons
Correct Answer: C
Rationale: The correct answer is C because high oxygen concentration in neonates suppresses normal blood vessel growth in the retina. When oxygen therapy is stopped, oxygen levels fall, triggering excessive blood vessel growth in the retina and vitreous humor, leading to fibrous blockage of light. Option A suggests fibrous tissue growth due to oxygen, which is incorrect. Option B inaccurately states that oxygen causes vessel rupture. Option D is incorrect as oxygen does not directly destroy retinal neurons.
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Which of the following suggestions should a nurse give breast-feeding mothers to prevent or eliminate mastitis and breast abscess?
- A. Offer the opposite breast at each feeding to their infants.
- B. Minimize frequent nursing of the infants.
- C. Avoid breast-feeding.
- D. Avoid bathing or showering regularly.
Correct Answer: A
Rationale: Alternating breasts during feedings helps prevent blockages and infections.
FSH causes several immature EGGS, along with their surrounding FOLLICLE cells, in the ovaries to begin to develop. The developing follicle cells release increasing amounts of ________________.
- A. hormone
- B. estrogen
- C. progesterone
- D. Implantation
Correct Answer: B
Rationale: Step-by-step rationale:
1. FSH stimulates development of follicles in ovaries.
2. Follicle cells release estrogen.
3. Estrogen levels increase as follicles develop.
4. Estrogen plays key role in menstrual cycle regulation.
Therefore, the correct answer is B (estrogen). Other choices are incorrect: A (hormones are broad, not specific), C (progesterone is released after ovulation), D (implantation occurs in the uterus, not ovaries).
Testosterone is secreted by the following structures, EXCEPT:
- A. prostate;
- B. testicular interstitial cells;
- C. seminiferous tubules;
- D. straight tubules;
Correct Answer: A
Rationale: The correct answer is A: prostate. Testosterone is primarily secreted by the testicular interstitial cells (Leydig cells) in the testes. The seminiferous tubules are responsible for spermatogenesis, not testosterone secretion. Straight tubules are involved in transporting sperm. The prostate gland produces prostatic fluid, not testosterone. Therefore, the prostate is not a structure that secretes testosterone.
A 22-yr-old patient reports her concern about not having a menstrual period for the past 7 months. Which statement by the patient indicates a possible related factor to the amenorrhea?
- A. “I drink at least 3 glasses of nonfat milk every day.”
- B. “I run 7 to 8 miles every day to manage my weight.”
- C. “I am not sexually active but currently I have an IUD
- D. “I was treated for a sexually transmitted infection 2 years ago.”
Correct Answer: B
Rationale: The correct answer is B. Running 7 to 8 miles daily can lead to amenorrhea due to excessive exercise-induced stress on the body, affecting hormone levels and menstrual cycle. This is known as exercise-induced amenorrhea. Choices A, C, and D do not directly correlate with amenorrhea. Choice A indicates a healthy calcium intake. Choice C suggests the presence of an IUD, which is not typically associated with amenorrhea. Choice D indicates a history of STI, which may not directly cause amenorrhea.
The secretion of ovarian hormones is controlled by:
- A. the anterior pituitary;
- B. the hypothalamus;
- C. FSH;
- D. LH;
Correct Answer: B
Rationale: The correct answer is B: the hypothalamus. The hypothalamus secretes gonadotropin-releasing hormone (GnRH) which stimulates the anterior pituitary to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which in turn regulate the secretion of ovarian hormones (estrogen and progesterone). The anterior pituitary secretes FSH and LH in response to GnRH from the hypothalamus. Therefore, the hypothalamus plays a crucial role in controlling the secretion of ovarian hormones. Choices A, C, and D are incorrect because the anterior pituitary releases FSH and LH but is not the primary controller, FSH is a hormone released by the anterior pituitary but is not the primary controller, and LH is released by the anterior pituitary but is not the primary controller of ovarian hormone secretion.