Introduction

The anatomy and function of the male genital organs fulfil certain roles during the reproductive process; copies of the man's genetic make up are packaged in spermatozoa which are produced in the testes. These gametes are then conducted along the male genital tract. Ejaculation results in their deposition in the vagina if intravaginal intercourse takes place. A simplified physiological anatomy of the male genital tract will be presented in this chapter.

The male sex organs

The male sex organs consist of the testes, excretory ducts, accessory glands and the penis (Table 1.1 and Figure 1.1). The testes (singular: testis) are two oval structures that normally lie in the scrotum (Figure 1.2). Each testis measures 4–6 cm in length and has a volume of about 25 ml. The testes produce spermatozoa (singular: spermatozoon) and testosterone (the male hormone). A mature spermatozoon is shown in Figure 1.3. It is a highly specialized cell that is designed for movement. The sole function of the spermatozoon is to carry a copy of the man's genetic make up, in the form of chromosomes, from the site of production in the testis, through the male and female genital tracts, to the egg that it fertilizes. The spermatozoon carries this genetic material in the head piece. The rest of the spermatozoon is made up of the mid-piece, which supplies the energy, and the tail which propels the sperm forward.