The penis is the male sexual organ that also serves as a common pathway and exit for semen and urine. It is made up of 3 groups of erectile tissue, namely the corpus spongiosum and two corpora cavernosa, covered by the fibrous tunica albuginea. The corpus spongiosum is where the urethra can be found.
The penis is divided into three parts: the root, the body, and the glans. The root is the part that is connected to the rest of the pelvic area. It is made up of the left and right crura and the bulb, which contain erectile tissues and the bulbospongiosus and ischiocavernosus muscles. The body of the penis is the part that is free and pendulous. Also known as the shaft, it mostly contains connective tissue and little muscles. The glans penis, or the head, is the conical part. The external urethral meatus, which is the opening of the urethra, can be found at the tip.
When the penis is stimulated, the penile arteries dilate. At the same time, the penile muscles contract, preventing the return of blood through the penile veins. These mechanisms eventually result in stiffening or erection, which is necessary for copulation, and subsequent ejaculation.
The penis also serves to expel urine from the body. In healthy males, voluntary relaxation of the urethral sphincter, which lies at the root, allows the influx of urine into the penis, facilitating urination.
Common Penile Problems and Conditions
Sexually transmitted diseases – Sexually transmitted diseases, or STDs, are a group of diseases that are transmitted via sexual contact. Symptoms are varied and include ulcers, discharge, and pain, among others. Commonly encountered STDs include chlamydia, gonorrhea, herpes, and syphilis.
Balanitis – Balanitis is an infection or inflammation of the head of the penis, commonly caused by poor hygiene in uncircumcised men.
Hypospadias – Hypospadias is a congenital abnormality wherein the external urethral meatus is located on the ventral portion of the penis.
Erectile dysfunction – Erectile dysfunction is a condition wherein a man is unable to develop or sustain an erection, resulting in poor sexual performance.
Priapism – Priapism is an erection that persists for several hours that is not related to sexual arousal or stimulation.
Common Penile Procedures and Surgeries
Circumcision – Circumcision is the most common surgery performed on the penis. It is typically done on children or infants as a cultural norm or for religious reasons. It may also be performed as treatment for certain conditions, such as phimosis. Circumcision involves the removal of the penile foreskin where it attaches to the glans. At present, however, there remains to be no consensus regarding the benefits of circumcision, and whether it should be universally performed or not.
Hypospadias repair – Repair of hypospadias is an operation performed to correct the congenital defect. In complex cases, complete repair requires a series of operations.
Penile prosthesis surgery – Penile prosthesis surgery is a form of treatment for erectile dysfunction. Implants used may either be malleable rods or inflatable prostheses.
Penile enlargement surgery – Penile enlargement is a form of surgery that increases the length or girth of the male penis.