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The prostate is a walnut-sized gonad (4x3x3cm), part of the male reproductive system. It is situated close to the urinary bladder where, ring-like, it surrounds the beginning of the urethra. The prostate lies on the anterior wall of the rectum, whose each side is crossed by important nerves and veins. The prostate is formed by two lobes (right and left). The part most distal from the bladder is called the apex, the part touching the bladder is the base. The gland has a shape of a blunt, slightly anterior-posterior flattened cone with base overturned up towards the bladder.

The prostate is crossed by the urethra (pars prostatica urethrae) and ductus ejaculatorii. The posterior wall of the urethra forms a longitudinal edge (crista urethralis). It contains a protuberance, colliculus seminalis (verumontanum), where the ductus ejaculatorii end. The sides of colliculus seminalis receive 15-30 ducts of prostatic glands.
Macroscopically, the prostate is divided into five glandular lobes, which are however visible only during the development. In adulthood these lobes are joined into one compact gland. The prostate surface shows only the lateral lobes (right and left) and the posterior lobe, while two small lobes are situated deep within the prostate. The middle lobe lies behind the urethra, in the angle between it and both ductus ejaculatorii. The anterior lobe, formed however mainly by connective tissue and muscles, is situated in front of the urethra.

The prostate is formed by approximately 50 typical prostatic glandules, the space in between them (stroma) is filled with connective tissue and smooth muscle cells. The stroma is typically located around the urethra, while the glandules are found at the prostate periphery. This fact is important for recognition of the symptoms connected with the most frequent prostate diseases. The prostate is surrounded by a solid fibrous sheath.

The seminal vesicle is formed by a ca 15 cm long and intricately folded tubule surrounded by connective tissue. The vesicle is about 5 cm long and its surface is uneven. The duct (ductus excretorius) fuses with the vas deferens just before its entry into the prostate. Seminal vesicles lie between the bladder and the rectum, laterally from the vas deferens ampullae.

The prostate produces a secretion forming 15-30% of the ejaculate volume. The secretion is fluid, colourless, of acidic reaction (pH 6.4), it contains zinc, citric acid, prostaglandins, polyamines - spermin and spermidin, immunoglobulins, acid phosphatase and proteases.

Zinc influences the metabolism of testosterone in the prostate; besides, it accumulates as a complex on the spermatic cell wall. Citric acid in the form of citrates functions as a buffer, prostaglandins stimulate uterine muscles and thus contribute to the sperm transport, spermin influences the motility of sperm and their capacity to fertilize the egg, proteases cause liquification of the ejaculate.

For its growth and correct functioning, the prostate needs male sexual hormones or androgens, of them namely testosterone. 90% of androgens in the male organism are represented by testosterone, which is formed in the Leydig cells of testes, 10% by dehydroepiandrosterone and androstendione produced by adrenal glands. 98% of testosterone is bound to the proteins of blood plasma (sex hormone-binding globulin - SHBG). Enzyme 5-alpha-reductase converts testosterone to dihydrotestosterone, which is bound to a specific cytoplasmic androgen receptor. Thus formed androgen-receptor complex is bound to specific sites on a DNA molecule in the cell nucleus. After transcription of androgen-dependent genes, specific proteins are generated and act on the stroma and glandular cells, maintaining the prostate activities.

The seminal vesicle is a geminate accessory gland of the male genital system, ensuring by its secretion the main volume of the ejaculate. The secretion contains fructose, prostaglandins and a number of proteins. Its production is dependent on testosterone.