Nokea
Which of the following is a false description of the negative feedback loop involved in the production of testosterone?
- A. Follicl
- B. stimulating hormone (FSH) targets the testes of males.
- C. Rising levels of testosterone promote increased release of gonadotropin releasing hormone (GnRH) from the hypothalamus.
- D. Gonadotropin releasing hormone (GnRH) is released by the hypothalamus; this hormone
Correct Answer: A
Rationale: The correct answer is A because follicle stimulating hormone (FSH) is not directly involved in the negative feedback loop for testosterone production. The negative feedback loop for testosterone involves the hypothalamus releasing GnRH, which stimulates the pituitary gland to release luteinizing hormone (LH), which then stimulates the Leydig cells in the testes to produce testosterone. Rising levels of testosterone inhibit the release of GnRH and LH through negative feedback to maintain hormonal balance. Choices B, C, and D are incorrect because they accurately describe components of the negative feedback loop for testosterone production.
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The gonads produce sex cells, also spermatids into sperm is known as known as ________, ________.
- A. zygotes
- B. mitosis
- C. interstitial cells
- D. spermiogenesis
Correct Answer: D
Rationale: The correct answer is D: spermiogenesis. Spermiogenesis is the process where spermatids mature into sperm cells in the testes. The gonads (testes in males) produce sex cells, but zygotes are formed through fertilization, not spermiogenesis. Mitosis is a type of cell division for growth and repair, not sperm production. Interstitial cells are found in the testes but are responsible for producing testosterone, not the maturation of spermatids into sperm cells. Therefore, option D is the correct choice as it specifically relates to the transformation of spermatids into sperm cells in the testes.
Following ejaculation, arterial blood flow into the corpora cavernosa decreases back to the normal resting level resulting in the flaccid state. What is the best explanation for this decrease in blood flow?
- A. Systemic arterial pressure decreases due to absence of sexual stimulation
- B. The level of sympathetic stimulation to the arterioles supplying the corpora cavernosa decreases
- C. Resistance of the arterioles supplying the corpora cavernosa increases
- D. Formation of nitric oxide in the endothelial cells of the arterioles supplying the corpora cavernosa is stimulated by the increase in parasympathetic nervous system activity
Correct Answer: C
Rationale: The correct answer is C because the resistance of the arterioles supplying the corpora cavernosa increases. This occurs due to the contraction of smooth muscle in the arterioles stimulated by sympathetic nervous system activity post-ejaculation. This constriction of arterioles reduces blood flow into the corpora cavernosa, leading to the flaccid state.
Choice A is incorrect because systemic arterial pressure does not decrease significantly post-ejaculation. Choice B is incorrect as decreased sympathetic stimulation would actually lead to vasodilation, not vasoconstriction. Choice D is incorrect because the release of nitric oxide by the parasympathetic nervous system would lead to vasodilation, not vasoconstriction.
How many seminiferous tubules are found in each lobule?
- A. 1-3
- B. 50-100
- C. 200-300
- D. 500 or more
Correct Answer: B
Rationale: The correct answer is B (50-100) because each lobule in the testis contains multiple seminiferous tubules where sperm production occurs. The average number of seminiferous tubules per lobule ranges from 50 to 100. This is supported by anatomical studies and research on testicular structure.
Explanation:
A: 1-3 - This is too low as each lobule contains more seminiferous tubules for efficient sperm production.
C: 200-300 - This is too high as it overestimates the number of seminiferous tubules per lobule.
D: 500 or more - This is excessive and not accurate based on scientific findings.
In summary, choice B is correct because it accurately reflects the typical range of seminiferous tubules per lobule, while the other choices either underestimate or overestimate this number.
The Fallopian tube is linked to the:
- A. vagina;
- B. uterus;
- C. ovary;
- D. vulva;
Correct Answer: B
Rationale: The correct answer is B: uterus. The Fallopian tube connects the ovaries to the uterus, allowing eggs to travel from the ovaries to the uterus for fertilization. The vagina (A) is not directly connected to the Fallopian tube but serves as the birth canal. The ovary (C) is where eggs are produced and released into the Fallopian tube, not directly linked to it. The vulva (D) is the external part of the female genitalia and is not connected to the Fallopian tube.
A patient comes in having had repeated colds and infections. Problems in his ear are shown to be due to accumulation of fluid in the middle ear. This is due to a blockage of the:
- A. Saccule
- B. Utricle
- C. External ear
- D. Eustachian tube
Correct Answer: D
Rationale: The correct answer is D: Eustachian tube. The Eustachian tube connects the middle ear to the back of the nose and throat, helping to equalize air pressure and drain fluid from the middle ear. Blockage of the Eustachian tube can lead to fluid accumulation in the middle ear, causing ear problems. The other choices, A: Saccule and B: Utricle, are structures in the inner ear related to balance and hearing, not fluid drainage. Choice C: External ear, refers to the outer ear structures and is not involved in middle ear fluid accumulation.