The Prostate Gland: Structure, Innervation, Functions, Symptoms and Examination

The prostate is a gland that is located in front of the rectum and below the bladder in males and those who were genetically predisposed to becoming male (AMAB). It is made up of glandular tissues and connective tissues. 

The prostate gland contributes fluid to the semen and helps push it through your urethra. Your prostate may be impacted by a number of disorders, including cancer, prostatitis, and benign prostatic hyperplasia.

The extra fluid in your semen (ejaculate) comes from your prostate. When you orgasm, your penis discharges ejaculate, a whitish-grey fluid. Zinc and citric acid in the fluid act as enzymes and lubricate your urethra while also nourishing sperm cells. You expel urine and ejaculate from your body through a channel called the urethra.

Additionally, when you orgasm, the muscles in your prostate aid in forcing semen into and through your urethra.

Anatomical Positioning Of Prostate Gland

The prostate, which is inferior to the bladder neck and superior to the external urethral sphincter, is placed inferior to the levator ani muscle.

Most significantly, the ampulla of the rectum is situated posterior to the prostate; this anatomical position is used during Digital Rectal Examinations (DRE), allowing medical practitioners to examine the gland.

Proteolytic enzymes leave the prostate through the prostatic ducts. These enter the urethra through 10–12 holes on either side of the seminal colliculus, also known as the verumontanum, and release enzymes into the semen soon before ejaculation.

Structure Of Prostate Gland

The prostate is typically described as being around the size of a walnut. The prostate is made up of roughly two-thirds glandular tissue and one-third fibromuscular tissue. A slim prostatic fibrous capsule encloses the gland itself. This isn't a true capsule; rather, it resembles the delicate connective tissue seen in major blood veins called the adventitia.

The urethra and the ejaculatory ducts traditionally divide the prostate into anatomical lobes (inferoposterior, inferolateral, superomedial, and anteromedial) as they pass through the organ.

The prostate is encircled by a capsule of connective tissue made up of muscle fibres. The prostate feels elastic to the touch because of this capsule. Scientists typically divide the prostate into four regions that encircle the urethra like the layers of an onion.

The prostate is made up of the following layers, starting with the outer capsule and ending inside the prostate:

• Medical experts refer to this region as the anterior fibromuscular zone since it is composed of muscle and fibrous tissues.
• Peripheral Zone: The majority of the glandular tissue is located here, mostly towards the back of the gland.
• Near 25% of the prostate's total mass is located in the central zone, which is located near the ejaculatory ducts.
• Transitional Zone: This is the region of the prostate that encircles the urethra. It's the only portion of the prostate that grows continuously throughout life.

Arterial Supply Of Prostate Gland

The prostatic arteries, which primarily originate from the internal iliac arteries, provide the vascular supply to the prostate. Some branches may also develop from the middle and internal pudendal arteries.

The prostatic venous plexus drains the prostate's bloodstream into the internal iliac veins. However, the internal vertebral venous plexus is also connected posteriorly to the prostatic venous plexus through networks of veins, including the Batson venous plexus.

Innervation Of Prostate Gland

The inferior hypogastric plexus innervates the prostate via sympathetic, parasympathetic, and sensory nerves. Sympathetic fibres that become active during ejaculation innervate the smooth muscle of the prostate gland.

Bundles of the neurovascular

The two neurovascular bundles that supply the corpora cavernosa's blood vessels and nerve fibres with the corpora cavernosa's blood are flanked by the prostate as they pass through the pelvic floor and head towards the penis. It is essential for a typical erection that these bundles remain intact.

One or both of these bundles frequently sustain damage during the radical prostatectomy procedure used to treat prostate cancer, which impairs erectile function. Special nerve-sparing procedures may be used to preserve these bundles from severe injury and enable postoperative potency.

Functions Of Prostate Gland 

Although having a healthy prostate is not necessary for survival, it is crucial for fertility. The functions of the prostate are covered in the sections below.

• Helping in the production of sperm- Prostatic fluid contribution to semen is the prostate's main purpose. 20–30% of the fluid that makes up the entire volume of semen comes from the prostate. The remaining portion (50–65%) and 5% are derived from the testicles and seminal vesicles, respectively.

Enzymes, zinc, and citric acid are among the ingredients found in the prostate fluid that make semen a perfect environment for sperm cells to survive in. Prostate-specific antigen (PSA), a crucial enzyme, aids in making semen drier and more fluid.

It is critical that the fluid in semen helps sperm in travelling through the urethra and surviving its journey to an egg for fertilization.

Although the prostatic fluid is slightly acidic, semen as a whole is alkaline. This will balance the vagina's pH and shield the sperm from harm.

• Urethra closure during ejaculation- The prostate contracts during ejaculation, squirting prostatic fluid into the urethra. Here, it combines with sperm cells and fluid from the seminal vesicles to form semen, which the body eventually excretes.

During ejaculation, the prostate contracts, blocking the urethral-bladder passage and forcing semen quickly through. This is why it is impossible to urinate and ejaculate at the same time in typical anatomical circumstances.

• Hormone synthesis- Androgens, or male sex hormones, including testosterone, are necessary for the prostate to function properly.

Dihydrotestosterone (DHT), a physiologically active version of testosterone, is produced by an enzyme called 5-alpha reductase found in the prostate.

The regular growth and function of the prostate depend on this hormone. It is essential for the development of secondary sex traits in the developing man, such as facial hair.

Symptoms Of Diseases Associated With Prostate

Urination and bladder control issues are frequently brought on by prostate disorders. These might include the following:

• Poor bladder control, including frequent visits to the bathroom,
• Urinary urgency, sometimes with just a tiny volume of urine,
• Difficulties starting the urine stream, or stopping and starting the stream while urinating
• A weak or thin urine stream
• Urinary tract infections, bladder stones, and, in severe situations, kidney failure can also be brought on by prostate issues.

One should seek medical help right away if they are completely unable to urinate.

If a person experiences any of the following symptoms, they should consult a doctor.

• Discomfort after ejaculating or while urinating
• Extreme discomfort penile, scrotal, or anus pain
• Blood in the urine
• Severe abdominal pain
• A weak pee stream or dribbling at the end of urinating
• Fever
• Body pain
• Difficulty controlling the bladder, such as stopping or postponing urination, inability to completely empty the bladder
• Urine with an odd odour or colour

Cancer of the Prostate

The second most frequent type of cancer in men, behind skin cancer, is prostate cancer. Approximately 1 in 8 boys will experience it at some point..

Prostate cancer is often discovered at age 66.

According to the American Cancer Society, people can decide whether to have a prostate cancer screening based on their age and risk factors, but they should be aware of the potential hazards of testing beforehand.

Prostatitis

Prostatitis is the medical term for prostate inflammation or enlargement. Males under 50 are most likely to experience this prostate issue. In the US, prostatitis affects between 10 and 15 per cent of males.

Urinary tract irritation that occurs suddenly is known as acute prostatitis. A bacterial infection can be to blame for this. When given the right antibiotics, it arises rapidly and goes away soon.

The terms "chronic prostatitis" or "chronic pelvic pain syndrome" are used when prostate inflammation lasts for more than three months.

Males over 50 are most likely to experience an enlarged prostate, also known as benign prostatic hyperplasia (BPH).

Enlarged Prostate

The urethra is squeezed and pressed by the expanding prostate, which narrows the urethra tube. Many of the problems associated with this condition are brought on by the narrowing of the urethra and a diminished capacity to empty the bladder. The bladder may weaken and lose its ability to empty completely as long as this illness lasts.

Urinating is made more challenging by an enlarged prostate, which in certain rare instances can also completely block urinating. Urinary retention is a medical condition that has to be evaluated right away.

Medical Examinations for the Prostate

Using different prostate exams, medical experts can identify prostate issues.

Typical prostate exams include:

• Digital rectal examination: During this examination, the doctor puts a finger into the rectum and feels the prostate to look for lumps, nodules, and indications of cancer.
• Blood tests can measure the PSA levels in the body. When these levels are high, the risk of prostate cancer increases.
• Prostate biopsy: If a doctor suspects cancer, he or she may extract a small sample of prostate tissue for analysis. They do this procedure by inserting a needle via the rectum into the prostate.

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