Male Reproductive Organ Showing Erect Penis _1

Image Caption : Male Reproductive Organ Showing Erect Penis : Three-dimensional visualization reconstructed from scanned human data. Anteriolateral view of the flaccid penis; also shown are the testicles vasa deferentia and the bladder which sits snuggly behind the pelvis.. There are three columns of erectile tissue in the penis: at the top (or dorsal side) of the penis are the two corpora cavernosa and at the bottom (or ventral side) is the corpus spongiosum. Upon arousal the arteries that supply the penis dilate and allow blood to fill the three spongy erectile tissue columns causing it to lengthen and stiffen. The engorged erectile tissue presses against penile veins preventing blood from flowing back out of the penis. 2 of 2.

Penile Erection

The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.

National Center for Biotechnology Information, U.S. National Library of Medicine


The penis, the male copulatory organ, is a cylindrical pendant organ located anterior to the scrotum and functions to transfer sperm to the vagina. The penis consists of three columns of erectile tissue that are wrapped in connective tissue and covered with skin. The two dorsal columns are the corpora cavernosa. The single, midline ventral column surrounds the urethra and is called the corpus spongiosum.

Illustration of the penis

The penis has a root, body (shaft), and glans penis. The root of the penis attaches it to the pubic arch, and the body is the visible, pendant portion. The corpus spongiosum expands at the distal end to form the glans penis. The urethra, which extends throughout the length of the corpus spongiosum, opens through the external urethral orifice at the tip of the glans penis. A loose fold of skin, called the prepuce, or foreskin, covers the glans penis.

National Cancer Institute / NIH

The material on this site is for informational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any medical condition. Consult a licensed medical professional for the diagnosis and treatment of all medical conditions and before starting a new diet or exercise program. If you have a medical emergency, call 911 immediately.