The Luteinizing hormone acts on the interstitial cells to produce

Correct Answer: D

Rationale: The correct answer is D, Testosterone. The luteinizing hormone acts on the interstitial cells in the testes to stimulate the production of testosterone. Testosterone is a male sex hormone responsible for the development of male reproductive tissues and characteristics. Androgen (choice A) is a broad term that includes testosterone, so it is not specific enough. Estrogen (choice B) and Progestin (choice C) are female sex hormones and are not produced by the interstitial cells in response to luteinizing hormone. Hence, the correct answer is D.

Correct Answer: D

Rationale: The correct answer is D: Depression. Sella turcica is a saddle-shaped depression in the sphenoid bone that houses the pituitary gland. It is not a groove (B) as it is a deeper concavity. It is not a projection (C) as it is a recessed area rather than a raised structure. It is not a foramen (A) as it is a hollowed-out area rather than a small opening. Therefore, the most accurate description of sella turcica is a depression in the sphenoid bone.

Correct Answer: A

Rationale: The sacrum is formed by the fusion of 5 originally separate sacral vertebrae. However, the coccyx is the result of the fusion of 4 originally separate coccygeal vertebrae. Therefore, the sacrum itself is formed by the fusion of 4 parts, making choice A correct. Choices B, C, and D are incorrect as they do not accurately reflect the anatomical structure of the sacrum.

Correct Answer: D

Rationale: The correct answer is D: STDs. Sexually transmitted diseases (STDs) can lead to pelvic inflammatory disease (PID) which can cause scarring and blockage of the fallopian tubes, leading to female infertility. STDs such as chlamydia and gonorrhea can also cause damage to the reproductive organs, affecting fertility. Therefore, STDs are a significant factor contributing to female infertility. A: A cold is a common viral infection that does not directly impact female fertility. B: Lack of appetite is not a known cause of female infertility. C: Irregular menstrual cycles can be a symptom of hormonal imbalances but may not directly lead to infertility.

Correct Answer: C

Rationale: The correct answer is C: helicine arteries. Helicine arteries are the main structures in erectile tissue responsible for maintaining an erection. They dilate in response to signals from the nervous system, allowing increased blood flow into the penis, leading to an erection. Pacinian corpuscles (A) are sensory receptors for touch and pressure, not involved in erectile function. Peripheral nerves (B) transmit signals between the brain and the penis but are not directly responsible for maintaining an erection. Acrosome phase (D) is a term related to sperm structure and not relevant to erectile tissue function.