Urethra

#55 Corpus spongiosum, H&E

This tissue is readily identified at lowest magnification by the characteristic shape of the lumen of the penile urethra and by the surrounding sponge-like arrangement of erectile tissue filled with blood. Study the epithelial lining of the penile urethra and observe that its appearance varies in different regions of the same section. Most frequently it appears to be pseudostratified or stratified columnar. Mucous glands may occur as nests of epithelial cells along the lining epithelium (intra-epithelial glands) or they may occur as more typical urethral glands (of Littre) whose ducts empty into local recesses of the urethral lumen.

The erectile tissue and the supporting fibro-muscular network of trabeculae that supports them are considered in the chapters on the male reproductive system.