Nokea
Two days before the onset of menstruation, secretions of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) reach their lowest levels. What is the cause of this low level of secretion?
- A. The anterior pituitary gland becomes unresponsive to the stimulatory effect of gonadotropin-releasing hormone (GnRH)
- B. Estrogen from the developing follicles exerts a feedback inhibition on the hypothalamus
- C. The rise in body temperature inhibits hypothalamic release of GnRH
- D. Secretion of estrogen, progesterone, and inhibin by the corpus luteum suppresses hypothalamic secretion of GnRH and pituitary secretion of FSH
Correct Answer: D
Rationale: The correct answer is D because two days before menstruation, the corpus luteum secretes estrogen, progesterone, and inhibin, which collectively suppress the hypothalamus's secretion of GnRH and the pituitary gland's secretion of FSH and LH. This hormonal feedback loop helps prepare the body for menstruation.
A: The anterior pituitary gland becoming unresponsive to GnRH does not explain the low FSH and LH levels.
B: Estrogen from developing follicles typically exerts a positive feedback on the hypothalamus, not inhibitory feedback.
C: The rise in body temperature does not directly impact FSH and LH levels; it is more related to ovulation.
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The superior region of the vagina is the _____.
- A. vaginal orifice
- B. cervix
- C. hymen
- D. vaginal rugae
Correct Answer: B
Rationale: The correct answer is B: cervix. The cervix is the lower portion of the uterus that protrudes into the vaginal canal. It is located at the superior region of the vagina. The vaginal orifice (A) refers to the opening of the vagina, not the superior region. The hymen (C) is a thin membrane that partially covers the vaginal opening and is not related to the superior region. Vaginal rugae (D) are the ridges or folds in the vaginal wall that allow for expansion, which are not specific to the superior region.
The internal male genital organs are represented by the following structures, EXCEPT:
- A. testicles;
- B. deferent ducts;
- C. corpora cavernosa;
- D. bulbourethral glands;
Correct Answer: C
Rationale: Step-by-step rationale for why choice C (corpora cavernosa) is correct:
1. Corpora cavernosa are erectile tissue in the penis, not internal male genital organs.
2. Testicles, deferent ducts, and bulbourethral glands are actual internal male genital organs.
3. Corpora cavernosa are involved in penile erection, not in male reproductive system functions.
Summary of why other choices are incorrect:
A: Testicles - Produces sperm and male sex hormones.
B: Deferent ducts - Transport sperm from the testicles to the urethra.
D: Bulbourethral glands - Produce pre-ejaculatory fluid to lubricate the urethra.
The ejaculatory duct is the union of the vas deferens and _____.
- A. seminal vesicle
- B. prostate
- C. ampulla
- D. urethra
Correct Answer: A
Rationale: The correct answer is A: seminal vesicle. The ejaculatory duct is formed by the union of the vas deferens and the seminal vesicle. The seminal vesicle contributes seminal fluid that mixes with sperm from the vas deferens to form semen. The prostate gland surrounds the ejaculatory duct but does not directly join it. The ampulla is an enlarged portion of the vas deferens but does not directly connect to the ejaculatory duct. The urethra is the tube that carries urine and semen out of the body but is not part of the ejaculatory duct. Therefore, the correct answer is A because the seminal vesicle directly joins with the vas deferens to form the ejaculatory duct.
Frank is a 24 year old man who presents with multiple vesicles and burning erosions on the shaft of his penis and some tender inguinal adenopathy. Which of the following is most likely?
- A. Primary syphilis
- B. Herpes simplex
- C. Chancroid
- D. Gonorrhea
Correct Answer: B
Rationale: The correct answer is B: Herpes simplex. This is because the presentation of multiple vesicles, burning erosions on the penis shaft, and inguinal adenopathy is classic for genital herpes. Primary syphilis (A) presents with a painless chancre, chancroid (C) with painful ulcers, and gonorrhea (D) with urethral discharge or dysuria. Genital herpes is a viral infection caused by HSV-1 or HSV-2 and typically presents with vesicles, erosions, and adenopathy in the affected area.
Which of the following is the male pattern of development “master switch” gene?
- A. SRY
- B. MIS
- C. XYY
- D. XXY
Correct Answer: A
Rationale: The correct answer is A: SRY. The Sex-determining Region Y (SRY) gene is the master switch for male development. It initiates the development of male gonads. Choice B, MIS, is a hormone involved in female reproductive development. Choices C and D, XYY and XXY, are genetic conditions related to male chromosomal variations and are not the master switch gene for male development.