Understanding The Male Reproductive System

A Modern Man's Guide To The Male Reproductive System

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.

What is the scrotum?

The scrotum is located under the penis and looks like a sac with two balls in it. These ball-like structures are known as the testes.

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 around the testes and pulls them closer to your body to keep them warm.

What is the penis?

Above the scrotum and between the legs, you’ll find the penis. The two main functions of the penis are erection and urination.

The penis has layers 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 and swells, making the penis hard and erect.

Penile erection positions the penis for entering into the female vagina. So, a healthy erection is important for sexual wellbeing.

What are the testes?

Testes, also called testicles, are the primary reproductive organ in men. They are gonads, which means they produce male reproductive cells and sexual hormones (androgens). Testes live outside the body in the scrotum.

The testicles are divided into different lobules. Each lobule acts as a separate room which contains numerous tiny U-shaped seminiferous tubules. One testicle has approximately 800 of these tightly coiled tubules.

The seminiferous tubules from each lobule converge into a network of channels called the rete testis. This network opens into the epididymis, where sperm is stored and matures before moving on.

The spermatic cord is made of tough connect tissue and houses nerves, blood vesseld and the vas deferens (see below). The spermatic cord also supports testes in the scrotum and connects it to the abdomen.

Testes have two types of cells: germ cells, and stromal cells:

What are germ cells?

Germ cells line the seminiferous tubules and carry out the process of spermatogenesis. The parent cells “spermatogonia” make sperm. The healthy function of germ cells is a primary requirement for male fertility. Sperm testing helps assess the performance of germ cells.

What are stromal cells

Stromal cells are non-germ cells of the testes. There are different types that perform various roles. Sertoli cells are present inside the seminiferous tubules. They secrete juices that nurse sperm and facilitate their transport out of the testes—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.

What is the epididymis?

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 main 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 help concentrate the sperm. The body grooms and makes them motile by the time they mature, and the tail store them until ejaculation. The epididymis is like the backstage area for sperm, where they become ready for getting out and performing their function.

What is the vas deferens?

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 connects to the urethra. Vas deferens is ligated during a vasectomy, which is a method of male contraception.

What are the accessory glands in the male reproductive system?

Seminal vesicles are important accessory glands in the male reproductive system. They make around 70% of the fluid that becomes semen.

The prostate resides between the penis and bladder, and secretes a small portion of semen that helps protect sperm.

Apart from these, some proportion of semen comes from the bulbourethral glands, also called Cowpar glands, to help with lubrication.

What is the urethra?

The urethra is the tubular structure inside the penis. It opens at the tip of the penis, allowing semen and urine to exit the body.

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.