THE MALE REPRODUCTIVE SYSTEM
Sexual reproduction is innate to most living things. Besides procreation, the sexual reproduction processes
provide a source of new varieties for a species as this chapter explains. Dr. Saladin also illuminates sex
determination in humans and then delves into the more quotidian aspects of the male reproductive system
such as the anatomy, physiology, and development of the sex organs as well as the control and
implementation of intercourse in men. Probably the most important clinical applications in this chapter
relate to sexually transmitted diseases.
Here are some concepts that students should have a better understanding of after reading this chapter:
sexual reproduction as a source of genetic diversity;
roles of the two gametes;
chromosomal sex determination;
the functions of the hormones in sex determination and the early development of sex organs;
descent, anatomy, and histology of the gonads;
structures and activities of the testis, scrotum, ducts, and accessory glands;
morphology of the penis;
factors governing the onset and progress of puberty and its consequences to the male’s body;
climacteric and other age-related changes in sexual physiology;
the processes of meiosis leading to haploid gametes and spermatogenesis and the structure of the
the functions and constituents of semen;
sexual intercourse, including regulation of excitement, erection, ejaculation, orgasm, and
and the causes, prevention, and treatments of common sexually transmitted diseases.
Topics for Discussion
Human papillomavirus (i.e., HPV) has emerged as a significant STD. Among the side effects of some
strains are cervical and penile cancers. Students should be encouraged to educate themselves about this
disease. Gardasil®, a vaccine effective against several varieties of HPV, is now being given to young
teenage females. Why not males too?
Impotence, prostatitis, and prostate cancer are topics that have been taboo for men. It is time for men to
discuss these problems as frankly as women discuss breast cancer.
Aneuploidies of sex chromosomes such as Turner, Klinefelter, etc. are interesting for students and
those syndromes are covered in chapter 29. However, the XYY condition is less discussed these days.
Most people expect those with an XYY karyotype to be more frequently involved in violent crimes
than XY men. For example, the convicted murderer Richard Speck was said to be XYY. Apparently,
the extra Y chromosome, being associated with male sex determination, is then also associated with
violence in some people’s minds. Mr. Speck (now also deceased), in reality, had a normal karyotype
(i.e., XY). Possibly, men should not be expected to be violent if we wish a healthy society.