Corpus spongiosum

Looks like

A single spongy cylinder along the underside of the penis, surrounding the urethra and expanding into the glans.

What it does

Protects the urethra and keeps it open during erection.

Keeping it well

Injury or infection can scar the urethra within it (stricture); a weakening urine stream or spraying needs checking.

Related conditions

• Bone metastases and spinal cord compression
• Erectile dysfunction
• Hypospadias
• Penile cancer
• Peyronie's disease
• Phimosis
• Premature ejaculation
• Priapism