Structure and Function of the Male Feline Reproductive Tract
The scrotum, because of its location, covering of dense hair, and its lack of fat, functions as a temperature regulator for the testicle and epididymis. The temperature within the scrotum is generally several degrees lower than the abdomen. This lower temperature is essential for the normal manufacturing and maintenance of sperm.
What Is the Male Feline Reproductive Tract?
The reproductive tract of the tom cat consists of the penis, two testicles, the scrotum, the prostate gland, two bulbourethral glands (Cowper's glands), the epididymis, the ductus deferens (also called the vas deferens), the spermatic cords, and the urethra.
Where Is the Male Feline Reproductive Tract Located?
The penis is located within the prepuce (a protective tubular sheath of skin). When the penis is not erect it is completely enclosed within the prepuce, which is visible on the posterior of the body between the two hind legs.
The scrotum is located just beneath the anus and above the prepuce. It is visible when the tail is lifted upwards. The scrotum is covered with dense hair and is not pendulous.
The testes, or testicles, are normally located within the scrotum.
The prostate gland is very small in the cat. It is normally located near the front of the rim of the pelvis at the back of the abdominal cavity. The prostate gland surrounds the beginning portion of the urethra and the termination of the ductus deferens.
The bulbourethral glands are situated on either side of the urethra.
The epididymis is an enlarged tube positioned along the edge of the testicle. Its beginning and end (head and tail) are located at the front and back of the testicle, respectively. There is one epididymis for each testicle.
The ductus deferens or vas deferens begins at the tail of the epididymis and runs along the border of the testicle, and then towards the back of the abdomen. It passes through the prostate and empties into the urethra.
The two spermatic cords are composed of the ductus deferens, and the vessels and nerves of the testicles. They are covered by a thin membrane. Each cord originates at the tail of the epididymis and extends back through the inguinal canal.
The urethra is a hollow tube that extends from the urinary bladder to the very tip of the penis. It carries urine from the bladder to the outside. The feline penile urethra is very narrow and much shorter than the urethra of the dog.
What Is the General Structure of the Male Feline Reproductive Tract?
The penis is covered by a protective sheath called the prepuce. The tip of the penis is called the glans, and it is covered with 120 to 150 penile spines that are directed backward, away from the end of the glans. These penile spines start to appear at about 12 weeks of age and are fully developed at puberty. They are absent in neutered male cats, disappearing by six weeks after castration. The penis is a highly vascularized structure. It surrounds the termination of the urethra and is important in directing the stream of urine to the outside of the body.
The scrotum is a pouch divided by a thin wall into two cavities, each of which is occupied by a testicle, an epididymis, and the tail end of the spermatic cord. The skin of the scrotum is covered with dense hair. The dartos of the scrotum is a layer of tissue that lies just under the skin and is made up of muscle and other tissue. Under the dartos is connective tissue that lines the scrotum.
Each testicle is round to oval in shape. The testicles contain seminiferous tubules that manufacture sperm. Special cells near the seminiferous tubules, called Sertoli cells, support and supply nutrition to the sperm cells.
The epididymis consists of an elongated structure composed of a long convoluted or twisted tube. It begins at the front end of the testicle and is positioned along the edge of the testicle.
The deferent ducts are thin muscular tubes that are made up of three layers of muscle.
The prostate gland surrounds the beginning of the urethra, as well as the end of the ductus deferens. The prostate has multiple openings into the urethra. It is very small, relatively unimportant organ in the male cat.
What Are the General Functions of the Male Feline Reproductive Tract?
The testicles perform two major functions that are largely complementary. They produce sperm and testosterone, a male hormone.
The epididymides are the organs where sperm are stored before ejaculation. In addition, they slowly transport sperm to the ductus deferens. The length of the epididymis and the slow transport of sperm are important in allowing the sperm time to become mature.
The ductus deferens transports sperm from the epididymis to the urethra by using strong contractions of the muscle wall.
The penis is the male copulatory organ. It contains vessels and connective tissue specialized to produce an erection, which facilitates penetration of the penis into the vagina of the female.
The prepuce acts as a moist protective covering for the non-erect penis.
What Are the Common Diseases of the Male Feline Reproductive Tract?
Cryptorchidism refers to the failure of one or both testicles to descend into the scrotum and remain there by seven to eight months of age. In the kitten, the testicles are initially located within the abdominal cavity. Within several days of birth, they begin to move downward and outward. Within six to eight weeks of age, they have moved into the scrotum. Failure of a testicle to move into the scrotum is called an undescended testicle, or cryptorchidism. The undescended testicle is often retained within the abdomen. Because the temperature of an undescended testicle is higher than normal, it is usually causes infertility.
Monorchidism is a rare developmental condition in which the affected individual only develops one testicle. It is important to note that this condition is often confused with unilateral (one-sided) cryptorchidism. Monorchidism is caused by a genetic abnormality and is uncommon.
Infertility is the inability to breed or produce a successful pregnancy.
Trauma may occur to the scrotum, prepuce and urethra. Such trauma may include blunt injuries from automobile accidents, bite wounds, and falling on to sharp objects.