The seminal vesicles are elongated exocrine glands with a highly folded mucosa. The folds divide the lumen into many cavities which may appear isolated in sections, but which actually all open into a larger central lumen. The epithelium is usually pseudostratified. Contractions of the smooth muscle surrounding each cavity are important in ensuring that seminal vesicle secretions become part of the semen during ejaculation. This is a section from the prostate of a young individual, and there are few, if any, concretions in such a prostate.
Concretions occur in adults and increase with age.
The tunica albuginea around each of the paired corpora cavernosa penis are the thickest and merge with each other. Small basal infolding from the epithelium form the glands of Littre which are mucus glands. In many instances, the glands of littre are intraepithelial glands but are continuous with glands of Littre in the lamina propria. The stroma around the urethra is richly cellular and vascular. Some of these sinuses are quite large and others smaller.