The penile urethra is enclosed by theSelect one:a.prepuce.b.corpus spongiosum.c.frenulum.d.corpus cavernosum.e.trabecular muscle.

To answer this multiple-choice question, we need to understand the anatomical structures related to the male reproductive system, specifically around the penile urethra.

Breakdown of the Options

1. Prepuce: This is the fold of skin that covers the glans, but it does not enclose the urethra itself.
2. Corpus Spongiosum: This is the erectile tissue that surrounds the urethra, allowing it to be maintained open during erection and involved in the passage of urine and semen.
3. Frenulum: This is a band of tissue underneath the glans that connects the prepuce to the glans, but it does not enclose the urethra.
4. Corpus Cavernosum: These are two columns of erectile tissue that run along the length of the penis but do not directly enclose the urethra.
5. Trabecular Muscle: This term is less commonly used, but it refers to smooth muscle in the corpora and is related to the overall structure without specifically enclosing the urethra.

Relevant Concepts

The penile urethra is primarily surrounded by the corpus spongiosum which is designed to protect the urethra during the erection.

Analysis and Detail

Among the provided options, the corpus spongiosum is the only structure that specifically encloses the penile urethra, allowing it to remain patent during urination and ejaculation.

Verify and Summarize

Through the understanding of the anatomy, it can be confirmed that the corpus spongiosum is indeed responsible for encasing the urethra while the other options do not serve this function.

Final Answer

b. corpus spongiosum