ThePenis consists of two dorsal masses of erectile tissue called the corpora cavernosa and a ventral mass called the corpus spongiosum (corpus cavernosum urethrae), the latter of which contains the urethra. The tunica albuginea is a dense fibroelastic tissue that binds all three together, forming a capsule around each. The cavernosa is lined with vascular endothelium, and will fill with blood while compressing the venous components. The penile skin is stratified squamous epithelium, which is thin and loosely attached. There is no adipose tissue and many sebaceous glands.