Male Accessory Ducts

The epididymis is a long, coiled, narrow tube located at the back of each testis. It is about 6 to 7 meters in length and partially encircles the testis. The epididymis serves as a connection between the testis and the vas deferens, facilitating sperm transport and maturation.

The epididymis is divided into three distinct parts:

The uppermost part, connected to the seminiferous tubules through the vasa efferentia. It receives immature sperms from the testis. Located at the superior pole of the testis.

The middle-elongated part of the epididymis. Provides a passage for sperm movement. Sperms start undergoing maturation here.

The lower end of the epididymis, connected to the vas deferens. Acts as a storage site for mature sperms before ejaculation. The cauda epididymis is also attached to the scrotal sac by connective tissue called gubernaculum.

Sperm Transport: Receives sperms from the testis via vasa efferentia. Transfers sperms from the caput epididymis to the cauda epididymis. Sperm Maturation: Sperms undergo physiological maturation as they pass through the epididymis. Develop motility and fertilizing capacity. Sperm Storage:  The cauda epididymis serves as a temporary storage site for sperms before they enter the vas deferens. Sperms can be stored here for two to three months. Secretion of Fluid: The epididymis secretes nutrient-rich fluid to nourish the sperms. Provides enzymes and proteins essential for sperm viability.

Structure: The vas deferens (plural: vas deferentia) originates from the epididymis. It is a muscular tube approximately 40 cm long that ascends through the inguinal canal to the abdomen. Loops over the urinary bladder and receives a duct from the seminal vesicle, forming the ejaculatory duct. The ejaculatory duct passes through the prostate gland and opens into the urethra.

Function: Transport of Sperm: The vas deferens is responsible for carrying mature sperm from the epididymis to the ejaculatory duct for ejaculation.

Structure: Ejaculatory ducts are a pair of ducts, each approximately 2 cm long. Formed by the union of the vas deferens and the duct of the seminal vesicle. They pass through the prostate gland and open into the urethra.

Function: The ejaculatory ducts serve as pathways for semen, transporting it from the seminal vesicle and vas deferens into the urethra. Semen then flows out of the body through the urethra, passing the prostate and exiting at the tip of the penis during ejaculation.

Definition: The urethra originates from the urinary bladder and extends through the penis to its external opening, called the urethral meatus. It serves as a common pathway for semen and urine secretion in males.

Divisions of the Male Urethra: 

Prostatic Urethra (First Part): Located within the prostate gland. It carries only urine.

Membranous Urethra (Second Part): Lies between the prostate gland and the root of the penis. It carries both semen and urine.

Penile Urethra (Third Part): Runs through the length of the penis. Functions to transport both semen and urine.

Additional Features: The urinary bladder receives a duct from the seminal vesicle, forming an ejaculatory duct that opens into the urethra. The prostate gland and bulbourethral glands (Cowper's glands) also release their secretions into the urethra, aiding in semen transport.