Which structure is composed of three cylindrical masses of erectile tissue each surrounded by a fibrous tissue?

Correct Answer: D

Rationale: The correct answer is D: Penis. The penis is composed of three cylindrical masses of erectile tissue (two corpora cavernosa and one corpus spongiosum) surrounded by fibrous tissue. The corpora cavernosa fill with blood during an erection, leading to rigidity. The other choices (A: Testes, B: Prostate, C: Bladder) do not fit the description of being composed of three cylindrical masses of erectile tissue surrounded by fibrous tissue. The testes are responsible for sperm production, the prostate is a gland that produces semen, and the bladder is a hollow muscular organ for storing urine.

Correct Answer: C

Rationale: The correct answer is C: Cough. Sexually transmitted diseases (STDs) are transmitted through sexual activity, not through coughing. Syphilis (A), Gonorrhea (B), and Genital Warts (D) are all STDs that are transmitted through sexual contact. Cough (C) is not a sexually transmitted disease as it is typically spread through respiratory droplets. Therefore, C is the correct answer as it does not fit the criteria of being an STD.

Correct Answer: A

Rationale: The correct answer is A: Chlamydia. Nongonococcal urethritis is primarily caused by Chlamydia trachomatis, a common sexually transmitted infection. Chlamydia is a major cause of urethritis in men. Gonorrhea (choice B) is another sexually transmitted infection but is not classified as nongonococcal urethritis. Herpes (choice C) and Syphilis (choice D) are caused by different pathogens and present with distinct symptoms, not typically associated with urethritis. Therefore, Chlamydia is the correct choice for Nongonococcal urethritis.

Correct Answer: C

Rationale: The correct answer is C: Bulbourethral glands. Cowper's gland is another name for the bulbourethral glands, which are responsible for producing a lubricating fluid that helps neutralize acidity in the urethra before ejaculation. The prostate gland (A) is responsible for producing seminal fluid, the testes (B) are responsible for producing sperm, and the preputial glands (D) are glands found in the foreskin of the penis. Therefore, the bulbourethral glands (C) are the correct answer because they align with the function and location of Cowper's gland.

Correct Answer: B

Rationale: The correct answer is B: Seminiferous tubules. These are the structures within the testes where sperm production occurs. This is the main function of testicular parenchymal tissue. Interstitial cells of Leydig (A) produce testosterone, spermatozoon (C) is a mature sperm cell, and semen (D) is a fluid that contains sperm and other substances. These choices are incorrect as they do not specifically represent the parenchymal tissue of the testes where sperm production takes place.