The prostate (from Ancient Greek ?????????, prostate , literally "standing person", "patron", "guardian") is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals. It is very different among species anatomically, chemically, and physiologically.
The function of the prostate is to secrete a little alkaline fluid, such as milk or white, which in humans is usually about 30% the volume of semen along with spermatozoa and seminal vesicle fluid. Cement is made whole base with secretions from other contributing glands, including, at least, seminal vesicle fluid. Alkalinity of semen helps neutralize the acidity of the vaginal tract, prolonging the life of sperm. Prostate fluid is excreted in the first ejaculatory fraction, together with most spermatozoa. Compared with some spermatozoa are ejected together with vesicular fluids especially seminalis, those expelled in prostate fluid have better motility, longer survival and better protection of genetic material.
The prostate also contains some smooth muscles that help to remove sperm during ejaculation.
Video Prostate
Structure
The classic description of a healthy male prostate describes it as slightly larger than a walnut. The mean normal prostate weight in adult males is about 11 grams, typically between 7 and 16 grams. One study suggested that prostate volume among patients with negative biopsy was significantly associated with weight and height (body mass index), so it was necessary to control weight. The prostate surrounds the urethra just below the bladder and can be felt during the rectal examination.
The secretory epithelium is primarily pseudostratified, composed of high columnar cells and basal cells supported by fibroelastic stroma - which contains random, random-oriented, straight-bladed muscle bonds. The epithelium is highly variable and the area of ​​cuboid or squamous epithelium is also present, with transitional epithelium in the distal areas of the longer channel. In the prostate, the urethra derived from the bladder is called the prostatic urethra and fused with two ejaculatory channels.
One can divide the prostate in two ways: by zone or lobe. It does not have a capsule; not an integral fibromuscular band surrounding it. It is coated by the pelvic floor muscles, which contract during the ejaculation process.
Zone
Classification "zones" are more commonly used in pathology. John E. McNeal first proposed the idea of ​​a "zone" in 1968. McNeal found that the relatively homogeneous surface of the prostate cut did not resemble the "lobe" and thus led to the "zone" description.
The prostate gland has four distinct gland regions, two of which arise from different segments of the prostatic urethra:
Lobes
Classification "lobe" is more commonly used in anatomy. Incomplete prostate is divided into five lobes:
Development
The prostate part of the urethra develops from the pelvic (middle) portion of the urogenital sinus (the endodermal origin). Endoskermal growth arises from the prostate part of the urethra and grows into surrounding mesenchyme. The epithelium of the prostate gland differentiates from these endodermal cells, and the associated mesenchyme differentiates into solid stroma and prostate smooth muscle. The prostate gland is a modified wall of the proximal portion of the male urethra and arises at the 9th week of embryonic life in the development of the reproductive system. Mesenchymal condensation, urethra and Wolffian ducts cause adult prostate gland, a composite organ composed of several gland and non-gland components that are closely attached.
Histology
- Glandular cells
- Mioepithelial cells
- Sub-key interstitial cells
Maps Prostate
Function
Male sexual response
During male semen emission, sperm is transmitted from the vas deferens to the male urethra through the ejaculatory duct, which lies within the prostate gland. Ejaculation is the expulsion of semen from the urethra. It is possible for some men to reach orgasm only through the stimulation of the prostate gland, such as prostate massage or anal intercourse.
Secretions
The secretion of the prostate varies between species. They are generally made up of simple sugars and often slightly alkaline. In human prostate secretion, the protein content is less than 1% and includes proteolytic enzymes, prostate phosphatase acid, beta-microseminoprotein, and prostate-specific antigen. Secretion also contains zinc with a concentration of 500-1000 times the concentration in the blood.
Rule
To function properly, the prostate requires male hormones (androgens), which are responsible for male sex characteristics. The main male hormone is testosterone, which is produced mainly by the testes. It is dihydrotestosterone (DHT), the testosterone metabolite, which mainly regulates the prostate.
Gene and protein expression
About 20,000 protein-encoding genes are expressed in human cells and nearly 75% of these genes are expressed in normal prostate. About 150 of these genes are more specifically expressed in the prostate with about 20 genes that are very specific prostate. Suitable specific proteins are expressed in glandular and secretory cells of the prostate gland and have important functions for cement characteristics. Examples of some prostate-specific proteins are enzymes, such as prostate specific antigen (PSA), and ACPP proteins.
Clinical interests
The prostate volume can be estimated by the formula of 0.52 ÃÆ'â € "long ÃÆ'â €" wide ÃÆ'â € "high. Volume more than 30 cm 3 is considered as prostatomegaly (enlarged prostate). Prostatomegaly can be caused by any of the following conditions.
Inflammation
Prostatitis is inflammation of the prostate gland. There are four main forms of prostatitis, each with different causes and outcomes. Two relatively uncommon forms, acute prostatitis and chronic bacterial prostatitis, are treated with antibiotics (categories I and II, respectively). Chronic non-bacterial prostatitis or male chronic pelvic pain syndrome (category III), which comprises about 95% of prostatitis diagnoses, is treated with major modalities including alpha blockers, physical therapy, psychotherapy, antihistamines, anxiolytics, nerve modulators, phytotherapy, , operations, and more. More recently, the combination of trigger points and psychological therapy has proven to be effective for category III prostatitis as well. Category IV prostatitis, relatively rare in the general population, is a type of leukocytosis.
Benign prostatic hyperplasia
Benign prostatic hyperplasia (BPH) occurs in older men; The prostate often enlarges to the point where urination becomes difficult. Symptoms include needing frequent urination (frequency) or taking a few moments to start (in doubt). If the prostate grows too large, it can constrict the urethra and inhibit the flow of urine, making urination difficult and painful and, in extreme cases, completely impossible.
BPH can be treated with medication, minimally invasive procedures or, in extreme cases, surgery that removes the prostate. Minimally invasive procedures include transurethral needle ablation from the prostate (TUNA) and transurethral microwave therapies (TUMT). This outpatient procedure may be accompanied by the insertion of a temporary prostate stent, to allow for normal urination, without exacerbating irritating symptoms. In some cases, "obesity management may be an effective method to reduce prostate volume."
The most commonly used surgery in such a case is called transurethral resection of the prostate (TURP or TUR). In TURP, the instrument is inserted through the urethra to remove the prostate tissue that compresses the upper part of the urethra and limits the flow of urine. TURP results in the removal of most transition zone networks in patients with BPH. Older men often have amylacea corpora (amyloid), accumulated solid calcium protein material, in their prostate canal. The amylacea corpora may block lumens from the prostate canal, and may underlie some cases of BPH.
Bladder frequency due to bladder spasm, common in older men, may be confused with prostate hyperplasia. The statistical observations show that low-fat and red meat and high-protein and vegetable diets, as well as regular alcohol consumption, may protect against BPH.
Lifestyle changes to improve the quality of urination include urinating in a sitting position. It reduces the amount of residual volume in the bladder, increases urinary flow rate and decreases urination time.
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%). However, the American Cancer Society's position on early detection is "Research has not proved that the potential benefits of testing outweigh the dangers of testing and treatment". They believe "that men should not be tested without learning about... the risks and possible benefits of testing and treatment" that should be discussed with a doctor at age 50 or at age 45 if the patient is black or has a father or brother. who obtained prostate cancer before the age of 65 years. If the examination is done, they may be in the form of a physical rectal examination, measurement of a specific level of prostate antigen (PSA) in the blood, or checking for the presence of Engrailed-2 (EN2) protein in the urine.
Co-investigators Hardev Pandha and Richard Morgan published their findings on the EN2 examination in urine in the March 1st issue of Clinical Cancer Research. The current laboratory test identifies EN2 in urine, and home test kits are conceivably similar to home pregnancy test strips. According to Morgan, "We are preparing for several major studies in the UK and in the US and although the EN2 test is not yet available, some companies have expressed an interest to move forward."
Vasectomy and risk of prostate cancer
In 1983, the Journal of the American Medical Association reported an association between vasectomy and an increased risk of prostate cancer. Research reported on 48,000 and 29,000 men who had vasectomy showed 66 percent and 56 percent higher prostate cancer rates, respectively. The risk increases with age and number of years since vasectomy is performed.
However, in March of the same year, the National Institute of Child Health and Human Development held a conference sponsored by the National Cancer Institute and others to review available data and information about the relationship between prostate cancer and vasectomy. It has been determined that the relationship between the two is very weak, and even if the vasectomy increases a person's risk, the risk is relatively small.
In 1997, NCI held a conference with Progressive Review Group prostate cancer (committee of scientists, medical personnel, and others). Their latest report, published in 1998 stated that evidence that vasectomy helps develop prostate cancer is the weakest.
In other mammals
The prostate is found as a male accessory gland in all placental mammals except edentata, martens, badger and beaver. The prostate glands of male marsupials are proportionally larger than that of placental mammals. In some marsupial species, the size of the prostate gland changes seasonally. The structure of the prostate varies, ranging from tubuloalveolar (as in humans) to tubular branched. This gland is very well developed in dogs, foxes and wild boars, although in other mammals, like bulls, it can be small and inconspicuous. Dogs can produce in an hour as much prostate fluid as humans can in one day. They secrete this fluid with their urine to mark their territory. In many rodents and bats, prostate fluid contains coagulants. It mixes with and coagulates semen during intercourse to form a marriage plug that prevents further copulation. In the cetacea the prostate gland is surrounded by a very strong muscle compressor.
The prostate gland originates with tissue in the urethral wall. This means the urethra, a compressible tube used for urination, travels through the middle of the prostate. This led to evolutionary design faults for some mammals, including male males. The prostate is susceptible to infection and later enlargement, narrowing the urethra so that urination becomes slow and painful.
Skene gland is found in humans and rodents. Historically it is considered a vestigial organ, but it has recently been found that it produces the same protein marker, PSA and PAB, as a male prostate. This means the function of Skene's gland as a female prostate, a histologic homologue to the male prostate gland.
Monotrem and marsupial mice have no prostate, but have a simpler cloacal gland that carries their function.
In the invertebrates
Kelenjar prostat juga terjadi pada beberapa spesies invertebrata, seperti gastropoda.
Gambar tambahan
Lihat juga
- Corpora amylacea
Tautan eksternal
- Media terkait dengan Prostat di Wikimedia Commons
- Prostat di Atlas Protein Manusia
- Daftar Istilah
Referensi
Sumber
- Bagian teks dari artikel ini berasal dari Publikasi NIH No. 02-4806, sebuah sumber daya domain publik. "Apa yang perlu saya ketahui tentang Masalah Prostat". 2002-06-01. Diarsipkan dari aslinya pada 2002-06-01 . Diperoleh 2011-01-24 .
Source of the article : Wikipedia
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