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CONTENTS

1_Prostate

2_Function

3_Regulation

4_Structure

5_Zones

6_Prostate disorders

7_Prostate cancer

8_Male sexual response

9_External links

10_References

This article uses material from Wikipedia,  "http://en.wikipedia.org/wiki/Prostate", the Wikimedia Commons  and from NIH Publication No. 02-4806, a public domain resource

For younger men, the most common prostate problem is prostatitis.
For  older men, it's an enlarged prostate!

 Prostate

The prostate is a exocrine gland of the male reproductive system. It is normally about the size of a walnut and is located immediately below the bladder.

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 Function

The main function of the prostate is to store and secrete a clear, slightly alkaline (pH 7.29) fluid that constitutes 10-30% of the volume of the seminal fluid that, along with spermatozoa, constitutes semen. The rest of the seminal fluid is produced by the two seminal vesicles. The alkalinity of seminal fluid helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm.
The prostate also contains some smooth muscles that help expel semen during ejaculation.

 Regulation

To work properly, the prostate needs male hormones (androgens), which are responsible for male sex characteristics.

The main male hormone is testosterone, which is produced mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands. However, it is dihydrotestosterone that regulates the prostate.

 Structure

A healthy human prostate is slightly larger than a walnut. It surrounds the urethra just below the urinary bladder and can be felt during a rectal exam.

The ducts are lined with transitional epithelium.

Within the prostate, the urethra coming from the bladder is called the prostatic urethra and merges with the two ejaculatory ducts. (The male urethra has two functions: to carry urine from the bladder during urination and to carry semen during ejaculation.) The prostate is sheathed in the muscles of the pelvic floor, which contract during the ejaculatory process.

The prostate can be divided in two different ways: by zone, or by lobe. [2]

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 Zones  

The "zone" classification is more often used in pathology.

The prostate gland has four distinct glandular regions, two of which arise from different segments of the prostatic urethra:

Peripheral zone (PZ)

Composes up to 70% of the normal prostate gland in young men

The sub-capsular portion of the posterior aspect of the prostate gland which surrounds the distal urethra. It is from this portion of the gland that more than 70% of prostatic cancers originate.

Central zone (CZ)

Constitutes approximately 25% of the normal prostate gland

This zone surrounds the ejaculatory ducts. Central zone tumours account for more than 25% of all prostate cancers.

Transition zone (TZ)

Responsible for 5% of the prostate volume

This zone is very rarely associated with carcinoma. The transition zone surrounds the proximal urethra and is the region of the prostate gland which grows throughout life and is responsible for the disease of benign prostatic enlargement.

Anterior fibro-muscular zone (or stroma)

Accounts for approximately 5% of the prostatic weight

This zone is usually devoid of glandular components, and composed only, as its name suggests, of muscle and fibrous tissue.

 Lobes 

The "lobe" classification is more often used in gross anatomy.

Anterior lobe (or isthmus)
roughly corresponds to part of transitional zone.

Posterior lobe
roughly corresponds to peripheral zone

Lateral lobes
spans all zones

Median lobe (or middle lobe)
roughly corresponds to part of central zone

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 Prostate disorders 

 Prostatitis 

Prostatitis is inflammation of the prostate gland. There are different forms of prostatitis, each with different causes and outcomes. Acute prostatitis and chronic bacterial prostatitis are treated with antibiotics; chronic non-bacterial prostatitis or male chronic pelvic pain syndrome, which comprises about 95% of prostatitis diagnoses, is treated by a large variety of modalities including alpha blockers, phytotherapy, physical therapy, psychotherapy, antihistamines, anxiolytics, nerve modulators and more.[3]
More recently, a combination of trigger point and psychological therapy has proved effective as well.[4]

 Benign prostatic hyperplasia 

Benign prostatic hyperplasia (BPH) occurs in older men;[5] the prostate often enlarges to the point where urination becomes difficult. Symptoms include needing to go to the toilet often or taking a while to get started. If the prostate grows too large it may constrict the urethra and impede the flow of urine, making urination difficult and painful and in extreme cases completely impossible.

BPH can be treated with medication or with surgery that removes the prostate. The surgery most often used in such cases is called transurethral resection of the prostate (TURP or TUR). In TURP, an instrument is inserted through the urethra to remove prostate tissue that is pressing against the upper part of the urethra and restricting the flow of urine. Older men often have corpora amylacea (amyloid), dense accumulations of calcified proteinaceous material, in the ducts of their prostates. The corpora amylacea may obstruct the lumens of the prostatic ducts, and may underlie some cases of BPH.

Urinary frequency due to bladder spasm, common in older men, may be confused with prostatic hyperplasia (enlarged prostate.)

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Prostate cancer 

Prostate cancer is one of the most common cancers affecting older men in developed countries and a significant cause of death for elderly men (estimated by some specialists at 3%).
Regular rectal exams are recommended for older men to detect prostate cancer early.

 Male sexual response  

During orgasm sperm are transmitted from the ductus deferens into the male urethra via the ejaculatory ducts, which lie within the prostate gland.

 References

  2  Instant Anatomy - Abdomen - Vessels - Veins - Prostatic plexus.

  3 Pharmacological treatment options for prostatitis/chronic pelvic pain syndrome (2006).

  4 Anderson RU, Wise D, Sawyer T, Chan CA (2006). "Sexual dysfunction in men with chronic prostatitis/chronic pelvic pain syndrome: improvement after trigger point release
    and paradoxical relaxation training". J. Urol. 176 (4 Pt 1): 15348; discussion 15389. doi:10.1016/j.juro.2006.06.010. PMID 16952676.

  5 Verhamme KM, Dieleman JP, Bleumink GS, et al (2002). "Incidence and prevalence of lower urinary tract symptoms suggestive of benign prostatic hyperplasia in primary
     care--the Triumph project". Eur. Urol. 42 (4): 3238. PMID 12361895

  External links

   "What I need to know about prostate problems" by the US National Institutes of Health.

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