Examine the trichrome-stained section of prostate gland on slide 95. Identify the tall epithelial cells with lightly stained "foamy" cytoplasm at the apical ends (Figs. 21-13 and 21-14) and in the stroma notice the smooth muscle fibers (red) mixed with dense connective tissue (blue). In the lumen identify the calcified, proteinaceous concretions called corpora amylacea (Fig. 21-16).

What explains the poor staining properties of the cells of the prostate?

What may cause corpora amylacea to form?

The association between prostate and urethra can be seen in the specimen on slide 47, which shows more of the gland surrounding urethra, although the latter has been split and appears on the "edge" of the section, unlike its disposition in Fig. 21-15. Notice the difference between the glandular tissue near the urethra and the glands throughout most of the organ further from the urethra.

Clinical note: Prostate glands provide urologists with plenty of work by being prone to three very common problems: (1) They are the site of chronic, low-grade bacterial infections. (2) In older men the secretory epithelium very frequently undergoes benign hyperplasia, resulting in so much tissue overgrowth that the urethra is often constricted and there are problems with urination. (3) Adenocarcinoma of the prostate epithelium is now the most common form of cancer in men.

Speculate why prostate infections are much more common than infections of seminal vesicles.

Could the same reasons explain why prostate cancer is so common and seminal vesicle cancer so rare?

The penis and urethra.