Which of the following statements relating to lactation is incorrect.

Correct Answer: B

Rationale: The correct answer is B because mechanical stimulation and neural inputs do not directly stimulate the anterior pituitary to secrete prolactin releasing factor and oxytocin. The release of prolactin is primarily controlled by the hypothalamus through the release of prolactin inhibitory hormone (dopamine) and prolactin releasing hormone. Oxytocin release is controlled by the hypothalamus in response to suckling. Choices A, C, and D are all correct statements about lactation. Plasma prolactin releasing factor (prolactin releasing hormone) does stimulate the release of prolactin, plasma oxytocin does stimulate milk ejection, and progesterone does prepare the mammary glands for lactation.

Correct Answer: A

Rationale: The correct answer is A: cervicitis. Cervicitis specifically refers to inflammation of the cervix, often due to an infection. Vaginitis (B) is inflammation of the vagina, not the cervix. Cercicopathy (C) is not a medical term. Vaginoplasty (D) is a surgical procedure to reconstruct or tighten the vagina, unrelated to inflammation or infection of the cervix.

Correct Answer: A

Rationale: The correct answer is A because the convoluted seminiferous tubules are indeed located in the lobules of the male gonad, which is the testis. These tubules are where spermatogenesis occurs, the process of sperm production. Option B is incorrect as the convoluted tubules do not continue with the deferent duct, but they connect to the straight tubules. Option C is incorrect because there are numerous convoluted seminiferous tubules within each testicular lobule, not just three. Option D is incorrect as the convoluted tubules do not continue with the straight tubules directly; they lead to the rete testis before connecting to the straight tubules.

Correct Answer: B

Rationale: Step-by-step rationale for why answer B is correct: 1. The external male genital organ is represented by the urethra, which is the duct that carries urine from the bladder out of the body. 2. The urethra is responsible for both urination and ejaculation. 3. The other choices are incorrect because the external male genital organ is not part of the urinary ducts, not a pair organ, and not located above the scrotum.

Correct Answer: C

Rationale: Step 1: The testicles are primarily responsible for producing male sex hormones. Step 2: Testosterone is the main male sex hormone secreted by the testes. Step 3: Testosterone is an androgenic hormone responsible for male characteristics. Step 4: Progesterone is a female sex hormone, not primarily secreted by the testicles. Step 5: Therefore, the correct answer is C (testosterone).