Male Reproductive System

The male reproductive system is made up of the penis, testicles, epididymes, vas deferens, prostate, and seminal vesicles.

Anatomy & Function of the Penis

The internal structure of the penis consists of two cylinder-shaped vascular tissue bodies (corpora cavernosa); the urethra (tube for expelling urine and ejaculate); erectile tissue surrounding the urethra; two main arteries; and several veins and nerves. The longest part of the penis is the shaft, at the end of which is the head, or glans penis. The opening at the tip of the glans, which allows for urination and ejaculation, is the meatus.

Anatomy & Function of the Testicles

The testicles, or testes, are the sperm- and testosterone-producing organs. They are located in a sac at the base of the penis called the scrotum. Each testicle is connected to a small, coiled tube called the epididymis, where sperm are stored for as long as 6 weeks while they mature.

The epididymes are connected to the prostate gland by a pair of tubes called the vas deferens. The vas deferens are part of a larger bundle of tissue, blood vessels, nerves, and lymphatic channels called the spermatic cord.

Anatomy & Function of the Prostate Gland

The prostate is a walnut-sized gland located beneath the bladder and in front of the rectum. It is surrounded by fibrous tissue called the prostate capsule. The urethra (tube that transports urine and semen out of the body) passes through the prostate to the bladder neck. The prostate produces prostate specific antigen (PSA) and prostatic acid phosphatase (an enzyme) that are present in seminal fluid (the milky substance that combines with sperm to form semen).

Anatomy & Function of the Seminal Vesicles

The seminal vesicles are saclike structures located close to the prostate. They secrete a thick fluid that mixes with seminal fluid produced by the prostate and sperm from the testes to form semen (ejaculate).

Publication Review By: Russell H. Williams, M.D.

Published: 29 Aug 2002

Last Modified: 30 Nov 2011