The prostate gland is a gland of the male reproductive system formed by fibrous tissue and muscle, whose main task is to produce and store seminal fluid, which is then released during ejaculation. It is located below the bladder and in front of the rectum, from which it is separated by a few centimetres.
What is the prostate?
The shape and the size of the prostate are reminiscent of those of a chestnut – about 3 cm long, 4 cm wide and 2.5 cm thick – with the narrower part facing downwards. In children it is present in a reduced size, and then it fully develops during puberty. At full sexual maturity the prostate generally weighs, under normal physiological conditions, between 10 and 20 grams. Made up of lobes, the prostate surrounds the first part of urethra, the key organ of the transport of urine out of the body. The central portion of the prostate gland surrounds the ejaculatory ducts; then there are two side lobes, front lobe and a peripheral lobe (the latter by itself constitutes about 70% of the entire volume of the gland). This gland can be the target of various diseases including inflammation, infection, cancerous malignancy, lithiasis and cysts.
The prostate gland is surrounded by a layer of connective tissue referred to as the prostatic capsule. Furthermore, the prostate gland is made of the following types of cells:
- Gland cells that produce the fluid portion of semen
- Fibrous cells that include the supportive structure of the prostate gland
- Muscle cells that control ejaculation and urine flow
Another structures that surround the prostate gland include:
- Seminal vesicles (glands that produce semen)
- Muscles (muscles that control urination)
- Nerve bundles (nerves that control bladder and erectile function)
- Vas deferens (tubes that carry sperm from the testicles to the seminal vesicles)
What function does the prostate serve?
The main function of the prostate gland is an exocrine function: it secretes prostatic fluid and in collaboration with the bulbourethral glands and the seminal vesicles – which are the so-called "accessory seminal glands" -it provides the production of sperm. In other words, the gland cells produce a fluid that is rich in proteins and minerals that maintain the sperm. The prostatic fluid is approximately a quarter of the total sperm and performs several functions: it increases sperm motility, reduces the acidity of urine and vaginal secretions, it allows a greater survival of sperm; it participates in the processes of coagulation and liquefaction of the sperm. When a man is sexually aroused, the prostate produces larger amounts of the prostatic fluid, which then mixes with sperm and it is ejaculated as semen.
The secretion of prostatic fluid is regulated through male hormones such as androgens, mainly produced by the testicles.
The prostate also has a role in the control of the flow of urine. The muscle fibres of the prostate are wrapped around the urethra and help control the flow of urine through contractions to slow down or stop the urine flow.
