About the penis

The penis consists of soft tissue which hangs between the legs. The average size in the relaxed state is eight centimetres in length and three centimetres in diameter. When erect, it is about 13 centimetres in length. Some penises are curved to the left or right. The penis has both a reproductive and a urinary function. It serves to deposit sperms in a woman's vagina and to deliver urine from the bladder through the urethra to the exterior.

Parts of the penis

The penis consists of three parts: the glans, the shaft and the root. Only the glans and the shaft are visible. The skin of the penis is very loose. This permits the penis to expand during erection. In newborns, the foreskin folds over the smooth rounded end of the penis, called the glans. During the first months of life, the foreskin adheres to the penis. The foreskin becomes unattached in most boys by age three.

Abnormalities

Hypospadias are congenital deformities of the penis resulting in the opening of the urethra being anywhere along the shaft of the penis or in more severe forms within the scrotum or pelvic area. The cause of hypospadias is not known, but it seems likely to be due to disrupted gene expression attributed to environmental chemicals. Phimosis is a condition where the foreskin of the penis is too tight and causes pain when the penis experiences an erection.

Hygiene

During bath times, the foreskin should be retracted and the penis cleaned. This serves to remove a cheesy looking substance called smegma. The latter is an oily substance (secreted by the glands underneath the foreskin) mixed with dead cells. Without proper hygiene, the smegma accumulates bacteria and causes infections of the penis. However the foreskin of newborns should not be forcibly retracted.

Circumcision

The surgical removal of the foreskin is called circumcision. The only clear medical requirement for circumcision is the inability to retract the foreskin after age three. However, circumcision has been practised for millennia among Egyptians and Ethiopians. Today, circumcision is practised by many religious groups.

Infections

Infections affecting the penis are often associated with sexual practice. The glans may become red, swollen and ulcers may appear. Pus or any unusual fluid from the uretral opening will indicate an infection within the urethra. These sexually transmitted infections include syphylis, genital herpes, gonorrhoea and chlamydia. Men with immunodeficient diseases such as diabetes mellitus or acquired immunodeficiency disorder (AIDS) may demonstrate a white cheesy substance on the penis due to candida. Genital warts on the penis are due to human papillomavirus.

Cancer

Cancers of the penis may take many and diverse forms. The lesions appear as a single papule (bump), a nodule, an erosion, a plaque or an ulcer. It may appear crusted and is confused with common inflammations of the skin. Velvety plaques under the foreskin or on the glans, which often itch, should be referred to a dermatologist for excision. These may represent carcinoma.

Dr Pauline Williams-Green is a family physician and president of the Caribbean College of Family Physicians; email: yourhealth@gleanerjm.com.