Nokea
Which of the following are all components of sperm?
- A. acrosome, flagellum, nucleus
- B. codpiece, flagellum, midpiece
- C. nucleus, seminal vesicles, mitochondria
- D. DNA, flagellum, efferent ductules
Correct Answer: A
Rationale: The correct answer is A: acrosome, flagellum, nucleus. The acrosome contains enzymes for penetrating the egg. The flagellum is the tail for movement. The nucleus contains genetic material. Choice B is incorrect because a codpiece is a protective garment and not a component of sperm. Choice C is incorrect because seminal vesicles and mitochondria are not components of sperm. Choice D is incorrect because efferent ductules are part of the male reproductive system, not a component of sperm.
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The endocrine role of the testicle:
- A. occurs at the level of the interstitial cells;
- B. consists in the secretion of androgenic hormones;
- C. consists in the secretion of testosterone;
- D. determines the maturation of the sex organs;
Correct Answer: C
Rationale: The correct answer is C because the endocrine role of the testicle primarily involves the secretion of testosterone. Testosterone is the main androgenic hormone produced by the testicles, which plays a crucial role in various physiological functions such as the development of male reproductive organs, sperm production, and secondary sexual characteristics.
Choice A is incorrect because while interstitial cells (Leydig cells) are involved in the production of testosterone, the endocrine role of the testicle is not limited to these cells alone.
Choice B is incorrect as it is too general. While androgenic hormones are indeed secreted by the testicles, testosterone specifically is the main androgenic hormone produced by them.
Choice D is incorrect as the maturation of sex organs is primarily regulated by the action of testosterone but is not the sole endocrine role of the testicle.
The pituitary FSH controls:
- A. the maturation of the ovarian follicles;
- B. the estrogen secretion;
- C. ovulation;
- D. the progesterone secretion;
Correct Answer: A
Rationale: The pituitary FSH (Follicle Stimulating Hormone) controls the maturation of ovarian follicles by stimulating their growth and development. FSH plays a crucial role in the early stages of the menstrual cycle. Estrogen secretion is primarily regulated by the ovaries, not FSH. Ovulation is mainly triggered by the surge in LH (Luteinizing Hormone) levels, not FSH. Progesterone secretion is mainly controlled by the corpus luteum, which forms after ovulation, not directly by FSH. Therefore, the correct answer is A as FSH directly influences the growth and maturation of ovarian follicles.
A female athlete who took testosterone-like steroids for several months stopped having normal menstrual cycles. What is the best explanation for this observation?
- A. Testosterone stimulates inhibin production from the corpus luteum
- B. Testosterone binds to receptors in the endometrium, resulting in the endometrium’s failure to develop during the normal cycle
- C. Testosterone binds to receptors in the anterior pituitary that stimulate the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- D. Testosterone inhibits the hypothalamic secretion of gonadotropin-releasing hormone and the pituitary secretion of LH and FSH
Correct Answer: D
Rationale: The correct answer is D because testosterone inhibits the hypothalamic secretion of gonadotropin-releasing hormone (GnRH) and the pituitary secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This disruption in the normal hormonal feedback loop leads to the suppression of ovulation and the menstrual cycle. Option A is incorrect because inhibin is not directly affected by testosterone. Option B is incorrect as testosterone does not bind to endometrial receptors directly. Option C is incorrect because testosterone does not stimulate the secretion of FSH and LH from the anterior pituitary.
Sperm are formed in tightly coiled tubes called seminiferous tubules that are found within each ________.
- A. spermatic cord
- B. testis
- C. ductus deferens
- D. epididymis
Correct Answer: B
Rationale: The correct answer is B: testis. The seminiferous tubules are located within the testes, where sperm are produced through the process of spermatogenesis. The spermatic cord (A) contains blood vessels, nerves, and the vas deferens but not the seminiferous tubules. The ductus deferens (C) is a tube that carries sperm from the epididymis to the urethra, not where sperm are formed. The epididymis (D) is where sperm mature and are stored but not where they are initially formed. Therefore, the testis is the only choice where the seminiferous tubules are located for sperm production.
The initiation of puberty and menses in a female, involves increased levels of _____.
- A. FSH
- B. LH
- C. estrogen
- D. progesterone
Correct Answer: C
Rationale: The correct answer is C: estrogen. During puberty in females, the hypothalamus signals the pituitary gland to release hormones, leading to increased estrogen levels. Estrogen plays a key role in the development of secondary sexual characteristics and the onset of menstruation. FSH and LH are also involved in the menstrual cycle but do not directly initiate puberty. Progesterone is mainly involved in the menstrual cycle's later stages, not the initiation of puberty.