A nurse is educating a client diagnosed with low testosterone. Which of the following physiological effects are attributed to testosterone in males? Select all that apply

Penile anatomy includes specialized erectile tissues, vascular structures, and sensory regions that function in urination, copulation, and ejaculation. The penis is composed of two corpora cavernosa and one corpus spongiosum, all enveloped in dense connective tissue. The glans penis, an extension of the corpus spongiosum, houses numerous sensory receptors. Normal penile erection involves vasodilation and blood filling of erectile tissues, with typical penile length in erect state ranging from 1B.9 to 1E.5 cm and penile arterial systolic velocity >30 cm/s indicating normal erectile function.

Rationale for correct answers

A. The corpora cavernosa are paired cylindrical erectile tissues located dorsolaterally in the penis. They are primarily responsible for penile rigidity during erection by engorging with blood via deep penile arteries.

C. The glans penis is the bulbous distal end of the penis, formed by the expansion of the corpus spongiosum. It is richly innervated and plays a key role in tactile sensation and sexual stimulation.

E. The corpus spongiosum is a single midline erectile structure surrounding the urethra. It prevents urethral compression during erection and expands distally to form the glans penis, contributing to both structure and function.

Rationale for incorrect answers

B. The rete testis is not a penile structure. It is a network of interconnecting tubules located in the mediastinum testis, responsible for collecting sperm from seminiferous tubules and transporting it to the epididymis. It has no structural or functional association with the penis.

D. The corpus luteum is a temporary endocrine structure formed from the ruptured ovarian follicle after ovulation in females. It secretes progesterone and estrogen. It is exclusive to the female reproductive system and unrelated to male genital anatomy.

Take home points

• The penis consists of corpora cavernosa, corpus spongiosum, and glans penis.
• Rete testis is located within the testes, not the penis.
• Corpus luteum is a female ovarian structure, not present in males.
• Erectile tissues are essential for penile rigidity and reproductive function.

Sperm maturation occurs in the epididymis, a highly coiled duct located along the posterior aspect of each testis. Spermatozoa produced in the seminiferous tubules are non-motile and incapable of fertilization until they pass through the epididymis, where they undergo biochemical and structural changes over a period of approximately 12 to 21 days. Mature sperm gain progressive motility and fertilizing capacity. Normal sperm motility should be ≥40%, and normal transit time through the epididymis ranges between 2 to 14 days, depending on frequency of ejaculation.

Rationale for correct answers

B. The epididymis is the primary site for sperm maturation and acquisition of motility. Immature sperm enter the head of the epididymis from the rete testis and progressively mature as they transit through the body and tail. This process is critical for sperm to acquire the ability to swim and fertilize an ovum.

Rationale for incorrect answers

A. The vas deferens functions as a transport conduit, carrying mature sperm from the epididymis to the ejaculatory ducts. It does not contribute to sperm maturation or motility development but is crucial during ejaculation.

C. The seminal vesicles secrete fructose-rich fluid contributing to semen volume and energy supply but do not play a role in sperm storage or maturation. Their function is exocrine, contributing fluid post-sperm maturation.

D. The ejaculatory ducts are short ducts formed by the union of the vas deferens and seminal vesicles. They pass through the prostate and open into the urethra. Their role is purely conductive, with no involvement in sperm development or motility acquisition.