Glans penis

The glans penis is a structure at the distal end of the penis in male mammals. It is the sensitive bulbous structure at the end of the human penis, and is anatomically homologous to the clitoral glans of the human female. The glans penis may be smooth, spiny, elongated, or divided in other mammals. The glans penis is a structure at the distal end of the penis in male mammals. It is the sensitive bulbous structure at the end of the human penis, and is anatomically homologous to the clitoral glans of the human female. The glans penis may be smooth, spiny, elongated, or divided in other mammals. Typically, the glans is completely or partially covered by the foreskin in humans, except in those who have been circumcised. The foreskin can generally be retracted over and past the glans, and may automatically retract during an erection. The glans is more commonly known as the 'head' or the 'tip' of the penis. The medical name comes from the Latin words glans ('acorn') and penis ('of the penis') – the Latin genitive of this word has the same form as the nominative. The glans penis is the expanded cap of the corpus spongiosum. It is moulded on the rounded ends of the corpora cavernosa penis, extending farther on their upper than on their lower surfaces. At the summit of the glans is the slit-like vertical external urethral orifice. The circumference of the base of the glans forms a rounded projecting border, the corona glandis, overhanging a deep retroglandular sulcus (the coronal sulcus), behind which is the neck of the penis. The proportional size of the glans penis can vary greatly. On some penises it is much wider in circumference than the shaft, giving the penis a mushroom-like appearance, and on others it is narrower and more akin to a probe in shape. The soft cushiony texture of the glans is intended to absorb impact during rigorous instances of copulation. The foreskin maintains the mucosa in a moist environment. Circumcised penises have a glans which is permanently exposed and dry. Several studies have suggested the glans is equally sensitive in both circumcised and uncircumcised penises, while others have reported it is more sensitive in people who are not circumcised. Halata & Munger (1986) report that the density of genital corpuscles is greatest in the corona glandis, while Yang & Bradley's (1998) report 'showed no areas in the glans to be more densely innervated than others.' Halata & Spathe (1997) reported; 'the glans penis contains a predominance of free nerve endings, numerous genital end bulbs and rarely Pacinian and Ruffinian corpuscles. Merkel nerve endings and Meissner's corpuscles are not present.' Yang & Bradley argue; 'the distinct pattern of innervation of the glans emphasizes the role of the glans as a sensory structure'. Some researchers have suggested that the glans has evolved to become acorn, mushroom or cone shaped so that during copulation it acts as a semen-removal device in the vagina of previous sex partners, but this is not supported when looking at primate relatives who have different mating behaviors. The meatus (opening) of the urethra is located at the tip of the glans penis. The epithelium of the glans penis is mucocutaneous tissue. Birley et al. report that excessive washing with soap may dry the mucous membrane which covers the glans penis and cause non-specific dermatitis.