Male fertility depends on the production of sperm (spermatogenesis) and their delivery to the female tract for fertilization. To ensure this, men need to have a functional reproductive system. Therefore, to understand male fertility, an overview of the male anatomy is crucial. We highly recommend reading about the male reproductive system in the sections below, and following up with our 10 Steps To Improve Sperm Quality guide.
The scrotum is the outer part of the male reproductive system. It is located between the legs and appears like a sac with two balls in it. These balls-like structures are known as the testes. The scrotum protects and warms the testes and attaches them to the penis.
A critical function of the scrotum is to provide a suitable temperature to testes for the production of sperm. When the external temperature is low, the scrotum shrinks and wraps around the testes to keep them warm.
Above the scrotum, the penis is also present between legs. It has three folds of spongy tissues supplied by a rich network of blood vessels. The function of spongy tissue is to produce an erection, which is a sign of sexual stimulation. When a man becomes aroused, the blood supply to the penis increases. Spongy tissue becomes engorged with blood, swells, and makes the penis erect.
Penile erection positions the penis for entering into the female vagina. So, a healthy erection is imperative for sexual wellbeing.
Testes are the primary reproductive organ in men. They are gonads, which means they produce male reproductive cells and sexual hormones (androgens). Testes also lie outside the body and in the scrotum. The outer layers of testes are robust with a protective function.
Inside these layers, testes divide into different lobules. Each lobule acts as a separate room which contains numerous tiny U-shaped seminiferous tubules. One testis has approximately 800 of these tightly coiled tubules.
The seminiferous tubules from each lobule converge into a network of channels called rete testis. These open into the epididymis, which connects the testes to the inner body. A tough connective tissue, the spermatic cord, supports testes in the scrotum.
Testes have two types of cells: germ cells, and stromal cells:
Germ cells line the seminiferous tubules and carry out the process of spermatogenesis. The parent cells “spermatogonia” make sperm; they reside in the seminiferous tubules since a male child’s birth. The healthy function of germ cells is a primary requirement for male fertility. Sperm testing assesses the performance of germ cells.
Stromal cells are non-germ cells of the testes. They have different types and perform various roles. The Sertoli cells are present inside the seminiferous tubules. They secrete juices that nurse sperm and facilitate their transport out of the testes. As sperm moving out of testes are partially mature and immobile, these secretions are vital for their delivery.
Another type of stromal cells is present in tissue that fills the spaces between different seminiferous tubules. These are Leydig cells, which secrete male sex hormones, especially testosterone.
Given that testes provide sites and tools for spermatogenesis, they are vital organs for determining male fertility.
The epididymis is a coiled tube, approximately 20 feet in length, which connects testes to the inner pelvis. It attaches to the rear end of the testes and has three parts: the head, body, and tail.
The head attaches to the upper poles of the oval-shaped testes. The body is extensively convoluted, and the tail continues into vas deferens. The head of the epididymis provides storage space for sperm. The body, however, grooms and makes them motile by their maturation. The epididymis is like a backstage area of sperm; there they become ready for getting out and performing their function.
Vas deferens is a tubular and less convoluted continuation of the epididymis. It provides a shuttle service to sperm. The length of the vas deferens is 35 to 45 cm. Their next stop is the ejaculatory duct, which passes through the pelvis and connects to the urethra. Vas deferens is ligated during a vasectomy, which is a method of male contraception.
Seminal vesicles are the primary glands of the male reproductive system. They have the most considerable contribution to the formation of semen.
The prostate resides between the penis and bladder, and secretes a small portion of semen.
Apart from these, some proportion of semen comes from the bulbourethral glands.
The urethra is the tubular structure inside the penis. It opens at the tip of the penis and semen which allows for semen to come out of it.
The male reproductive system starts and ends outside the body. The ducts take sperm from the testes, pass them through the pelvic cavity, and bring them back to the penis.