Nokea
Before intercourse, a woman irrigates her vagina with a solution that lowers the pH of the vaginal fluid to 4.5. What will be the effect on sperm cells in the vagina?
- A. Metabolic rate will increase
- B. Rate of movement will decrease
- C. Formation of prostaglandin E2 will increase
- D. Rate of oxygen consumption will increase
Correct Answer: B
Rationale: The correct answer is B: Rate of movement will decrease. Sperm cells require a slightly alkaline environment to maintain their motility. Lowering the pH to 4.5 will create an acidic environment, causing decreased sperm motility. Choice A is incorrect as lowering pH doesn't affect metabolic rate. Choice C is incorrect because prostaglandin E2 formation is not directly related to pH changes. Choice D is incorrect as oxygen consumption rate of sperm cells is not affected by vaginal pH.
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Where does spermatogenesis occur?
- A. Interstitial cells.
- B. Seminal vesicles.
- C. Seminiferous tubules.
- D. Vas deferens.
Correct Answer: C
Rationale: The correct answer is C: Seminiferous tubules. Spermatogenesis is the process of sperm production, which occurs in the seminiferous tubules of the testes. These tubules contain specialized cells called Sertoli cells and spermatogonia that undergo multiple stages of cell division and maturation to form spermatozoa. Interstitial cells (A) produce testosterone, seminal vesicles (B) secrete seminal fluid, and vas deferens (D) is the duct that carries sperm from the testes to the urethra but is not the site of spermatogenesis.
Which of the following is not a role of semen?
- A. Semen dilutes sperm.
- B. The acidity of semen helps neutralize the pH environment of a female's vagina
- C. Semen contains enzymes that enhance sperm motility.
- D. Semen contains antibiotic chemicals that destroy bacteria
Correct Answer: C
Rationale: The correct answer is C because semen does not contain enzymes that enhance sperm motility. Sperm motility is primarily influenced by the structure and health of the sperm themselves. Semen aids in sperm transport, provides nutrients, buffers the acidic vaginal environment, and contains antibiotics. Enzymes in semen primarily help with liquefaction of semen after ejaculation, not sperm motility. Choices A, B, and D are incorrect because semen does dilute sperm, neutralizes the acidic vaginal environment, and contains antibiotic chemicals, respectively.
Which of the following is the primary sign of breast cancer?
- A. A bloody discharge from the nipple
- B. A dimpling of the skin over the lesion
- C. A retraction of the nipple
- D. A painless mass in the breast
Correct Answer: D
Rationale: A painless mass is often the first noticeable sign of breast cancer.
The following statements about the prostate are true:
- A. it is an exocrine glandular organ;
- B. it is an unpaired organ;
- C. it secretes a fluid that is part of the semen;
- D. it is vascularized by a branch of the internal iliac artery;
Correct Answer: A
Rationale: Step-by-step rationale for the correct answer (A):
1. The prostate gland is an exocrine gland because it secretes its products through ducts onto an epithelial surface.
2. It is a paired organ, with two lobes located above the urethra and below the bladder.
3. The prostate secretes a fluid that contributes to the seminal fluid, not semen itself.
4. The prostate is vascularized by branches of the internal iliac artery, not the entire gland.
Therefore, the correct statement is that the prostate is an exocrine glandular organ (Choice A).
Rita Chen, who is 25 years old and knows that she is not pregnant, is concerned because she has not had a menstrual period for three months. Her doctor described this condition as ______.
- A. dysmenorrhea
- B. amenorrhea
- C. menometrorrhagia
- D. polymenorrhoea
Correct Answer: B
Rationale: The correct answer is B: amenorrhea. Amenorrhea refers to the absence of menstrual periods, which is the condition Rita Chen is experiencing. Dysmenorrhea is painful periods, not absence of periods. Menometrorrhagia is excessive and prolonged menstrual bleeding. Polymenorrhoea is frequent menstrual periods, not absence of periods. In this case, Rita's lack of periods for three months aligns with the definition of amenorrhea.