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102-522: The PC3 cell line was established in 1979 from bone metastasis of grade IV of prostate cancer in a 62-year-old Caucasian male. These cells do not respond to androgens, glucocorticoids or fibroblast growth factors, but results suggest that the cells are influenced by epidermal growth factors. PC3 cells can be used to create subcutaneous tumor xenografts in mice to investigate the tumor environment and therapeutic drug functionality. PC3 cells have high metastatic potential compared to DU145 cells, which have

204-499: A C-reactive protein may be elevated in an infection. Some forms of medical imaging exist to visualise the bladder. A bladder ultrasound may be conducted to view how much urine is within the bladder, indicating urinary retention . A urinary tract ultrasound , conducted by a more trained operator, may be conducted to view whether there are stones, tumours or sites of obstruction within the bladder and urinary tract. A CT scan may also be ordered. A flexible internal camera, called

306-419: A cystoscope , can be inserted to view the internal appearance of the bladder and take a biopsy if required. Urodynamic testing can help to explain the symptoms. All species of mammal have a urinary bladder. This structure begins as an embryonic cloaca . In the vast majority of species, it eventually becomes differentiated into a dorsal part, connected to the intestine, and a ventral part, associated with

408-401: A "glandular flesh upon which rests the neck of the bladder," and Vesalius as a "glandular body". The first time a word similar to prostate was used to describe the gland is credited to André du Laurens in 1600, who described it as a term already in use by anatomists at the time. The term was however used at least as early as 1549 by French surgeon Ambroise Pare . At the time, Du Laurens

510-423: A circadian rhythm, meaning day and night cycles, it is not entirely clear how these are disturbed in the overactive bladder. Urodynamic testing can help to explain the symptoms. An underactive bladder is the condition where there is a difficulty in passing urine and is the main symptom of a neurogenic bladder . Frequent urination at night may indicate the presence of bladder stones . Disorders of or related to

612-411: A combination of trigger point and psychological therapy has proved effective for category III prostatitis as well. An enlarged prostate is called prostatomegaly, with benign prostatic hyperplasia (BPH) being the most common cause. BPH refers to an enlargement of the prostate due to an increase in the number of cells that make up the prostate ( hyperplasia ) from a cause that is not a malignancy. It

714-494: A condition in which the bladder is infected due to a cause that is not bacteria. Frequent urination can be due to excessive urine production, small bladder capacity, irritability or incomplete emptying. Males with an enlarged prostate urinate more frequently. One definition of an overactive bladder is when a person urinates more than eight times per day. An overactive bladder can often cause urinary incontinence . Though both urinary frequency and volumes have been shown to have

816-401: A distinct tissue, but present throughout the relevant part of the urethra; in other animals, such as red deer and American elk , it may be present as a specific organ and in a disseminate form. In some marsupial species, the size of the prostate gland changes seasonally. The prostate is the only accessory gland that occurs in male dogs. Dogs can produce in one hour as much prostatic fluid as

918-424: A human can in a day. They excrete this fluid along with their urine to mark their territory . Additionally, dogs are the only species apart from humans seen to have a significant incidence of prostate cancer. The prostate is the only male accessory gland that occurs in cetaceans , consisting of diffuse urethral glands surrounded by a very powerful compressor muscle. The prostate gland originates with tissues in

1020-402: A middle layer of circular fibres, and an outermost layer of longitudinal fibres; these form the detrusor muscle, which can be seen with the naked eye. The outside of the bladder is protected by a serous membrane called adventitia . In the developing embryo , at the hind end lies a cloaca . This, over the fourth to the seventh week, divides into a urogenital sinus and the beginnings of

1122-526: A moderate metastatic potential, and to LNCaP cells, which have low metastatic potential. Comparisons of the protein expression of PC3, LNCaP, and other cells have shown that PC3 is characteristic of small cell neoendocrine carcinoma . PC3 cells have low testosterone - 5-alpha reductase and acidic phosphatase activity, and do not express PSA ( prostate-specific antigen ). Furthermore, karyotypic analysis has shown that PC3 are near-triploid, having 62 chromosomes. Q-band analysis showed no Y chromosome. From

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1224-468: A morphological point of view, electron microscopy revealed that PC3 cells show characteristics of a poorly-differentiated adenocarcinoma . They have features common to neoplastic cells of epithelial origins, such as numerous microvilli, junctional complexes, abnormal nuclei and nucleoli, abnormal mitochondria, annulate lamellae, and lipoidal bodies. This cell biology article is a stub . You can help Misplaced Pages by expanding it . Prostate This

1326-437: A person does not have symptoms; when they do occur, symptoms may include urinary frequency, urgency, hesitation and other symptoms associated with BPH. Uncommonly, such cancers may cause weight loss, retention of urine, or symptoms such as back pain due to metastatic lesions that have spread outside of the prostate. A digital rectal examination and the measurement of a prostate-specific antigen (PSA) level are usually

1428-467: A procedure. A perineal approach will not involve lymph node removal and may result in less pain and a faster recovery following an operation. A TURP procedure uses a tube inserted into the urethra via the penis and some form of heat, electricity or laser to remove prostate tissue. The whole prostate can be removed. Complications that might develop because of surgery include urinary incontinence and erectile dysfunction because of damage to nerves during

1530-401: A reflex based in the spine, with higher inputs from the brain. During urination, the detrusor muscle contracts, the external urinary sphincter and muscles of the perineum relax, and urine flows through the urethra and exits the penis or vulva through the urinary meatus . The urge to pass urine stems from stretch receptors that activate when between 300 - 400 mL urine is held within

1632-487: A sample of urine for an inspection for malignant cells under a microscope, called cytology , as well as medical imaging by a CT urogram or ultrasound . If a concerning lesion is seen, a flexible camera may be inserted into the bladder, called cystoscopy , in order to view the lesion and take a biopsy , and a CT scan will be performed of other body parts (a CT scan of the chest, abdomen and pelvis ) to look for additional metastatic lesions. Treatment depends on

1734-400: A urethral branch, supplying the urethral prostate; and a capsular branch, which travels around the capsule and has smaller branches, which perforate into the prostate. The veins of the prostate form a network – the prostatic venous plexus , primarily around its front and outer surface. This network also receives blood from the deep dorsal vein of the penis , and is connected via branches to

1836-421: Is able to change its length. It can also contract for a long time whilst voiding , and it stays relaxed whilst the bladder is filling. The wall of the urinary bladder is normally 3–5 mm thick. When well distended, the wall is normally less than 3 mm. In males, the prostate gland lies outside the opening for the urethra. The middle lobe of the prostate causes an elevation in the mucous membrane behind

1938-401: Is an accepted version of this page The prostate is an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation . It is found in all male mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the bladder , with the urethra passing through it. It

2040-471: Is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular tissue, as well as connective tissue . The prostate produces and contains fluid that forms part of semen , the substance emitted during ejaculation as part of the male sexual response . This prostatic fluid is slightly alkaline , milky or white in appearance. The alkalinity of semen helps neutralize

2142-400: Is known as bladder cancer . It is usually due to cancer of the urothelium , the cells that line the surface of the bladder. Bladder cancer is more common after the age of 40, and more common in men than women; other risk factors include smoking and exposure to dyes such as aromatic amines and aldehydes . When cancer is present, the most common symptom in an affected person is blood in

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2244-408: Is located in the pelvis. It sits below the urinary bladder and surrounds the urethra . The part of the urethra passing through it is called the prostatic urethra , which joins with the two ejaculatory ducts . The prostate is covered in a surface called the prostatic capsule or prostatic fascia . The internal structure of the prostate has been described using both lobes and zones. Because of

2346-494: Is very common in older men. It is often diagnosed when the prostate has enlarged to the point where urination becomes difficult. Symptoms include needing to urinate often ( urinary frequency ) or taking a while to get started ( urinary hesitancy ). If the prostate grows too large, it may constrict the urethra and impede the flow of urine, making urination painful and difficult, or in extreme cases completely impossible, causing urinary retention . Over time, chronic retention may cause

2448-511: The Skene's gland and the male prostate act similarly by secreting prostate-specific antigen (PSA), which is an ejaculate protein produced in males, and of prostate-specific acid phosphatase , the Skene's gland is sometimes referred to as the "female prostate". Although homologous to the male prostate (developed from the same embryological tissues), various aspects of its development in relation to

2550-423: The allantois . The upper and lower parts of the bladder develop separately and join around the middle part of development . At this time the ureters move from the mesonephric ducts to the trigone. In males, the base of the bladder lies between the rectum and the pubic symphysis. It is superior to the prostate , and separated from the rectum by the recto-vesical pouch . In females, the bladder sits inferior to

2652-408: The anal canal , with a wall forming between these two inpouchings called the urorectal septum . The urogenital sinus divides into three parts, with the upper and largest part becoming the bladder; the middle part becoming the urethra , and the lower part changes depending on the biological sex of the embryo. The human bladder derives from the urogenital sinus , and it is initially continuous with

2754-408: The dorsal columns in the spinal cord . When viewed under a microscope , the bladder can be seen to have an inner lining (called epithelium ), three layers of muscle fibres, and an outer adventitia . The inner wall of the bladder is called urothelium , a type of transitional epithelium formed by three to six layers of cells; the cells may become more cuboidal or flatter depending on whether

2856-423: The inferior vesical artery , internal pudendal artery , and middle rectal arteries . These vessels enter the prostate on its outer posterior surface where it meets the bladder, and travel forward to the apex of the prostate. Both the inferior vesical and the middle rectal arteries often arise together directly from the internal iliac arteries . On entering the bladder, the inferior vesical artery splits into

2958-402: The internal iliac arteries . In females, the uterine and vaginal arteries provide additional blood supply. Venous drainage begins in a network of small vessels on the lower lateral surfaces of the bladder, which coalesce and travel with the lateral ligaments of the bladder into the internal iliac veins . The lymph drained from the bladder begins in a series of networks throughout

3060-408: The prostatic acid phosphatase . In the developing embryo , at the hind end lies an inpouching called the cloaca . This, over the fourth to the seventh week, divides into a urogenital sinus and the beginnings of the anal canal , with a wall forming between these two inpouchings called the urorectal septum . The urogenital sinus divides into three parts, with the middle part forming the urethra;

3162-415: The semen . Its secretion forms up to 30% of the semen. Semen is the fluid emitted ( ejaculated ) by males during the sexual response . When sperm are emitted, they are transmitted from the vas deferens into the male urethra via the ejaculatory duct , which lies within the prostate gland. Ejaculation is the expulsion of semen from the urethra. Semen is moved into the urethra following contractions of

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3264-411: The superior and inferior hypogastric plexuses and nerves, and from parasympathetic fibers, which come from the pelvic splanchnic nerves . Sensation from the bladder, relating to distension or to irritation (such as by infection or a stone) is transmitted primarily through the parasympathetic nervous system. These travel via sacral nerves to S2-4 . From here, sensation travels to the brain via

3366-403: The trigone of the bladder . These ureteric openings have mucosal flaps in front of them that act as valves in preventing the backflow of urine into the ureters, known as vesicoureteral reflux . Between the two ureteric openings is a raised area of tissue called the interureteric crest. This makes the upper boundary of the trigone. The trigone is an area of smooth muscle that forms the floor of

3468-415: The uterus , separated by the vesicouterine pouch , and is supported by the elevator ani and the upper part of the vagina . The bladder receives blood by the vesical arteries and drained into a network of vesical veins . The superior vesical artery supplies blood to the upper part of the bladder. The lower part of the bladder is supplied by the inferior vesical artery , both of which are branches of

3570-457: The vesical plexus and internal pudendal veins . Veins drain into the vesical and then internal iliac veins . The lymphatic drainage of the prostate depends on the positioning of the area. Vessels surrounding the vas deferens , some of the vessels in the seminal vesicle, and a vessel from the posterior surface of the prostate drain into the external iliac lymph nodes . Some of the seminal vesicle vessels, prostatic vessels, and vessels from

3672-465: The "male G-spot ". Prostatitis is inflammation of the prostate gland. It can be caused by infection with bacteria, or other noninfective causes. Inflammation of the prostate can cause painful urination or ejaculation, groin pain, difficulty passing urine, or constitutional symptoms such as fever or tiredness . When inflamed, the prostate becomes enlarged and is tender when touched during digital rectal examination . The bacteria responsible for

3774-482: The 1966 Nobel Prize in Physiology or Medicine . The role of the gonadotropin-releasing hormone (GnRH) in reproduction was determined by Andrzej W. Schally and Roger Guillemin , who both won the 1977 Nobel Prize in Physiology or Medicine for this work. GnRH receptor agonists, such as leuprorelin and goserelin , were subsequently developed and used to treat prostate cancer. Radiation therapy for prostate cancer

3876-451: The 1970s. The initial regimen of cyclophosphamide and 5-fluorouracil was quickly joined by multiple regimens using a host of other systemic chemotherapy drugs. The prostate is found only in mammals. The prostate glands of male marsupials are proportionally larger than those of placental mammals. The presence of a functional prostate in monotremes is controversial, and if monotremes do possess functional prostates, they may not make

3978-403: The 19th century. The first treatments of prostate cancer were surgeries to relieve urinary obstruction. Samuel David Gross has been credited with the first mention of a prostatectomy, as "too absurd to be seriously entertained" The first removal for prostate cancer (radical perineal prostatectomy ) was first performed in 1904 by Hugh H. Young at Johns Hopkins Hospital ; partial removal of

4080-455: The acidity of the vaginal tract , prolonging the lifespan of sperm . The prostatic fluid is expelled in the first part of ejaculate, together with most of the sperm, because of the action of smooth muscle tissue within the prostate. In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid, those in prostatic fluid have better motility , longer survival, and better protection of genetic material. Disorders of

4182-485: The anterior lobe or isthmus, the posterior lobe, the right and left lateral lobes, and the middle or median lobe. Inside of the prostate, adjacent and parallel to the prostatic urethra, there are two longitudinal muscle systems. On the front side ( ventrally ) runs the urethral dilator ( musculus dilatator urethrae ), on the backside ( dorsally ) runs the muscle switching the urethra into the ejaculatory state ( musculus ejaculatorius ). The prostate receives blood through

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4284-477: The anterior prostate drain into internal iliac lymph nodes . Vessels of the prostate itself also drain into the obturator and sacral lymph nodes . The prostate consists of glandular and connective tissue . Tall column-shaped cells form the lining (the epithelium ) of the glands. These form one layer or may be pseudostratified . The epithelium is highly variable and areas of low cuboidal or flat cells can also be present, with transitional epithelium in

4386-409: The apex on to the abdominal wall to form the middle umbilical fold . The neck of the bladder is the area at the base of the trigone that surrounds the internal urethral orifice that leads to the urethra. In males, the neck of the urinary bladder is next to the prostate gland . The bladder has three openings. The two ureters enter the bladder at ureteric orifices , and the urethra enters at

4488-404: The base of the pelvis . In gross anatomy , the bladder can be divided into a broad fundus (base), a body, an apex, and a neck. The apex (also called the vertex) is directed forward toward the upper part of the pubic symphysis , and from there the median umbilical ligament continues upward on the back of the anterior abdominal wall to the umbilicus . The peritoneum is carried by it from

4590-447: The bladder ( radical cystectomy ), with the ureters diverted into a segment of part of ileum connected to a stoma bag on the skin. Prognosis can vary markedly depending on the cancer's stage and grade, with a better prognosis associated with tumours found only in the bladder, that are low grade, that do not invade through the bladder wall, and that is papillary in visual appearance. A number of investigations are used to examine

4692-488: The bladder above the urethra. It is an area of smooth tissue for the easy flow of urine into and from this part of the bladder - in contrast to the irregular surface formed by the rugae. The walls of the bladder have a series of ridges, thick mucosal folds known as rugae that allow for the expansion of the bladder. The detrusor muscle is the muscular layer of the wall made of smooth muscle fibers arranged in spiral, longitudinal, and circular bundles. The detrusor muscle

4794-401: The bladder include: Disorders of bladder function may be dealt with surgically, by redirecting the flow of urine or by replacement with an artificial urinary bladder . The volume of the bladder may be increased by bladder augmentation . An obstruction of the bladder neck may be severe enough to warrant surgery. Ultrasound can be used to estimate bladder volumes. Cancer of the bladder

4896-493: The bladder is a key site of absorption for many major ions in marine fish urine is held in the bladder for extended periods to maximise water absorption. The urinary bladders of fish and tetrapods are thought to be analogous while the former's swim-bladders and latter's lungs are considered homologous. Most fish also have an organ called a swim-bladder which is unrelated to the urinary bladder except in its membranous nature. The loaches , pilchards , and herrings are among

4998-461: The bladder is empty or full. Additionally, these are lined with a mucous membrane consisting of a surface glycocalyx that protects the cells beneath it from urine. The epithelium lies on a thin basement membrane , and a lamina propria . The mucosal lining also offers a urothelial barrier against the passing of infections. These layers are surrounded by three layers of muscle fibres arranged as an inner layer of fibres orientated longitudinally,

5100-485: The bladder of the Galapagos tortoise could store urine weighing up to 20% of the tortoise's body weight. Such adaptations are the result of environments, such as remote islands and deserts, where fresh water is very scarce. Other desert-dwelling reptiles have large bladders, which can hold long-term reserves of water for several months and aid in osmoregulation . Turtles have two or more accessory urinary bladders, beside

5202-432: The bladder to become larger and cause a backflow of urine into the kidneys ( hydronephrosis ). BPH can be treated with medication, a minimally invasive procedure or, in extreme cases, surgery that removes the prostate. In general, treatment often begins with an alpha-1 adrenergic receptor antagonist medication such as tamsulosin , which reduces the tone of the smooth muscle found in the urethra that passes through

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5304-415: The bladder. As urine accumulates, the rugae flatten and the wall of the bladder thins as it stretches, allowing the bladder to store larger amounts of urine without a significant rise in internal pressure. Urination is controlled by the pontine micturition center in the brainstem . Stretch receptors in the bladder signal the parasympathetic nervous system to stimulate the muscarinic receptors in

5406-419: The bladder. The investigations that are ordered will depend on the taking of a medical history and an examination. The examination may involve a medical practitioner feeling in the suprapubic area for tenderness or fullness that might indicate an inflamed or full bladder. Blood tests may be ordered that may indicate inflammation; for example a full blood count may demonstrate elevated white blood cells , or

5508-579: The body is usually treated also with hormone therapy, to deprive a tumour of sex hormones (androgens) that stimulate proliferation. This is often done through the use of GnRH analogues or agents (such as bicalutamide ) that block the receptors that androgens act on; occasionally, surgical removal of the testes may be done instead. Cancer that does not respond to hormonal treatment, or that progresses after treatment, might be treated with chemotherapy such as docetaxel . Radiotherapy may also be used to help with pain associated with bony lesions. Sometimes,

5610-495: The cancer's stage . Cancer present only in the bladder may be removed surgically via cystoscopy ; an injection of the chemotherapeutic mitomycin C may be performed at the same time. Cancers that are high grade may be treated with an injection of the BCG vaccine into the bladder wall, and may require surgical removal if it does not resolve. Cancer that is invading through the bladder wall may be managed by complete surgical removal of

5712-420: The choice of operation type and details of the procedure of the chosen technique. The effects on postoperational urination and ejaculation vary correspondingly. It is possible for some men to achieve orgasm solely through stimulation of the prostate gland, such as via prostate massage or anal intercourse . This has led to the area of the rectal wall adjacent to the prostate to be popularly referred to as

5814-412: The decision may be made not to treat prostate cancer. If a cancer is small and localised, the decision may be made to monitor for cancer activity at intervals ("active surveillance") and defer treatment. If a person, because of frailty or other medical conditions or reasons, has a life expectancy less than ten years, then the impacts of treatment may outweigh any perceived benefits. Surgery to remove

5916-546: The detrusor and even outnumber β3 receptors, but they do not have as important an effect in relaxing the detrusor smooth muscle. Cystitis refers to infection or inflammation of the bladder. It commonly occurs as part of a urinary tract infection . In adults, it is more common in women than men, owing to a shorter urethra . It is common in males during childhood, and in older men where an enlarged prostate may cause urinary retention. Other risk factors include other causes of blockage or narrowing, such as prostate cancer or

6018-549: The detrusor to contract the muscle when the bladder is distended. This encourages the bladder to expel urine through the urethra. The main receptor activated is the M3 receptor , although M2 receptors are also involved and whilst outnumbering the M3 receptors they are not so responsive. The main relaxant pathway is via the adenylyl cyclase cAMP pathway, activated via the β3 adrenergic receptors. The β2 adrenergic receptors are also present in

6120-489: The dissolved salts in their urine are highly dilute. The urinary bladder helps these animals to retain salts. Some aquatic amphibians, such as Xenopus , do not reabsorb water from their urine, to prevent excessive water influx. For land-dwelling amphibians, dehydration results in reduced urine output. The amphibian bladder is usually highly distensible; among some land-dwelling species of frogs and salamanders, it may account for 20%–50% of total body weight. Urine flows from

6222-411: The few types of fish in which a urinary bladder is poorly developed. It is largest in those fish which lack an air bladder, and is situated in front of the oviducts and behind the rectum . In nearly all bird species, there is no urinary bladder per se. Although all birds have kidneys, the ureters open directly into a cloaca which serves as a reservoir for urine, fecal matter, and eggs. Unlike

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6324-419: The first investigations done to check for prostate cancer. PSA values are difficult to interpret, because a high value might be present in a person without cancer, and a low value can be present in someone with cancer. The next form of testing is often the taking of a prostate biopsy to assess for tumour activity and invasiveness. Because of the significant risk of overdiagnosis with widespread screening in

6426-536: The general population, prostate cancer screening is controversial. If a tumour is confirmed, medical imaging such as an MRI or bone scan may be done to check for the presence of tumour metastases in other parts of the body. Prostate cancer that is only present in the prostate is often treated with either surgical removal of the prostate or with radiotherapy or by the insertion of small radioactive particles of iodine-125 or palladium-103 , called brachytherapy . Cancer that has spread to other parts of

6528-547: The gland was conducted by Theodore Billroth in 1867. Transurethral resection of the prostate (TURP) replaced radical prostatectomy for symptomatic relief of obstruction in the middle of the 20th century because it could better preserve penile erectile function. Radical retropubic prostatectomy was developed in 1983 by Patrick Walsh. In 1941, Charles B. Huggins published studies in which he used estrogen to oppose testosterone production in men with metastatic prostate cancer. This discovery of "chemical castration " won Huggins

6630-545: The infection may be detected by a urine culture . Acute prostatitis and chronic bacterial prostatitis are treated with antibiotics . Chronic non-bacterial prostatitis, or male chronic pelvic pain syndrome is treated by a large variety of modalities including the medications alpha blockers , non-steroidal anti-inflammatories and amitriptyline , antihistamines , and other anxiolytics . Other treatments that are not medications may include physical therapy , psychotherapy , nerve modulators , and surgery . More recently,

6732-425: The internal urethral orifice called the uvula of urinary bladder. The uvula can enlarge when the prostate becomes enlarged. The bladder is located below the peritoneal cavity near the pelvic floor and behind the pubic symphysis . In males, it lies in front of the rectum, separated by the rectovesical pouch , and is supported by fibres of the levator ani and of the prostate gland. In females, it lies in front of

6834-444: The kidneys through the ureters into the bladder and is periodically released from the bladder to the cloaca. The gills of most teleost fish help to eliminate ammonia from the body, and fish live surrounded by water, but most still have a distinct bladder for storing waste fluid. The urinary bladder of teleosts is permeable to water, though this is less true for freshwater dwelling species than saltwater species. In freshwater fish

6936-490: The male prostate are widely unknown and a matter of research. Urinary bladder The bladder is a hollow organ in humans and other vertebrates that stores urine from the kidneys . In placental mammals , urine enters the bladder via the ureters and exits via the urethra during urination . In humans, the bladder is a distensible organ that sits on the pelvic floor . The typical adult human bladder will hold between 300 and 500 ml (10 and 17 fl oz ) before

7038-416: The most common is E coli . When a urinary tract infection or cystitis is suspected, a medical practitioner may request a urine sample . A dipstick placed in the urine may be used to see if the urine has white blood cells , or the presence of nitrates which may indicate an infection. The urine specimen may be also sent for microbial culture and sensitivity to assess if a particular bacteria grows in

7140-510: The mucosal, muscular and serosal layers. These then form three sets of vessels: one set near the trigone draining the bottom of the bladder; one set draining the top of the bladder; and another set draining the outer undersurface of the bladder. The majority of these vessels drain into the external iliac lymph nodes . The bladder receives both sensory and motor supply from sympathetic and the parasympathetic nervous systems . The motor supply from both sympathetic fibers, most of which arise from

7242-550: The neck of the urinary bladder and above the pubis, occupying much of the body cavity. Turtles' bladder is also usually divided into two lobes: the right lobe is under the liver, which prevents large stones from remaining in the lobe; the left lobe is likelier than the right to have calculi . Most aquatic and semi-aquatic amphibians can absorb water directly through their skin. Some semi-aquatic animals also have similarly permeable bladder membranes. They tend to have high rates of urine production, to offset this high water intake; and

7344-424: The normal prostate. About 150 of these genes are more specifically expressed in the prostate, with about 20 genes being highly prostate specific. The corresponding specific proteins are expressed in the glandular and secretory cells of the prostatic gland and have functions that are important for the characteristics of semen , including prostate-specific proteins , such as the prostate specific antigen (PSA) , and

7446-405: The operation, particularly if a cancer is very close to nerves. Ejaculation of semen will not occur during orgasm if the vasa deferentia are tied off and seminal vesicles removed, such as during a radical prosatectomy. This will mean a man becomes infertile . Sometimes, orgasm may not be able to occur or may be painful. The penis length may shorten slightly if the part of the urethra within

7548-430: The outer regions of the longer ducts. Basal cells surround the luminal epithelial cells in benign glands. The glands are formed as many follicles, which drain into canals and subsequently 12–20 main ducts, These in turn drain into the urethra as it passes through the prostate. There are also a small amount of flat cells, which sit next to the basement membranes of glands, and act as stem cells. The connective tissue of

7650-501: The presence of vesico-ureteric reflux ; the presence of outside structures in the urinary tract, such as urinary catheters ; and neurologic problems that make passing urine difficult. Infections that involve the bladder can cause pain in the lower abdomen (above the pubic symphysis , so called "suprapubic" pain), particularly before and after passing urine, and a desire to pass urine frequently and with little warning ( urinary urgency ). Infections are usually due to bacteria , of which

7752-459: The prostate and transurethral microwave thermotherapy . These outpatient procedures may be followed by the insertion of a temporary stent , to allow normal voluntary urination, without exacerbating irritative symptoms. Prostate cancer is one of the most common cancers affecting older men in the UK, US, Northern Europe and Australia, and a significant cause of death for elderly men worldwide. Often,

7854-409: The prostate can also be removed from within the urethra, called transurethral resection of the prostate (TURP). Open surgery may involve a cut that is made in the perineum , or via an approach that involves a cut down the midline from the belly button to the pubic bone . Open surgery may be preferred if there is a suspicion that lymph nodes are involved and they need to be removed or biopsied during

7956-539: The prostate include enlargement , inflammation , infection , and cancer . The word prostate is derived from Ancient Greek prostátēs ( προστάτης ), meaning "one who stands before", "protector", "guardian", with the term originally used to describe the seminal vesicles . The prostate is a exocrine gland of the male reproductive system . In adults, it is about the size of a walnut , and has an average weight of about 11 grams (0.39 oz), usually ranging between 7 and 16 grams (0.25–0.56 oz). The prostate

8058-410: The prostate include proteolytic enzymes , prostatic acid phosphatase , fibrinolysin , zinc , and prostate-specific antigen . Together with the secretions from the seminal vesicles, these form the major fluid part of semen. The prostate's changes of shape, which facilitate the mechanical switch between urination and ejaculation, are mainly driven by the two longitudinal muscle systems running along

8160-613: The prostate is also removed. General complications due to surgery can also develop, such as infections , bleeding , inadvertent damage to nearby organs or within the abdomen, and the formation of blood clots . The prostate was first formally identified by Venetian anatomist Niccolò Massa in Anatomiae libri introductorius (Introduction to Anatomy) in 1536 and illustrated by Flemish anatomist Andreas Vesalius in Tabulae anatomicae sex (six anatomical tables) in 1538. Massa described it as

8262-436: The prostate is called prostatectomy, and is usually done as a treatment for cancer limited to the prostate, or prostatic enlargement. When it is done, it may be done as open surgery or as laparoscopic (keyhole) surgery . These are done under general anaesthetic . Usually the procedure for cancer is a radical prostatectomy , which means that the seminal vesicles are removed and the vasa deferentia are also tied off. Part of

8364-449: The prostate is made up of fibrous tissue and smooth muscle . The fibrous tissue separates the gland into lobules. It also sits between the glands and is composed of randomly orientated smooth-muscle bundles that are continuous with the bladder. Over time, thickened secretions called corpora amylacea accumulate in the gland. About 20,000 protein-coding genes are expressed in human cells and almost 75% of these genes are expressed in

8466-423: 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 . It is dihydrotestosterone (DHT), a metabolite of testosterone, that predominantly regulates the prostate. The prostate gland enlarges over time, until the fourth decade of life. The prostate secretes fluid, which becomes part of

8568-459: The prostate, making it easier for urine to pass through. For people with persistent symptoms, procedures may be considered. The surgery most often used in such cases is transurethral resection of the prostate , in which 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 . Minimally invasive procedures include transurethral needle ablation of

8670-550: The prostatic urethra. These are the urethral dilator ( musculus dilatator urethrae ) on the urethra's front side, which contracts during urination and thereby shortens and tilts the prostate in its vertical dimension thus widening the prostatic section of the urethral tube, and the muscle switching the urethra into the ejaculatory state ( musculus ejaculatorius ) on its backside. In case of an operation, e.g. because of benign prostatic hyperplasia (BPH), damaging or sparing of these two muscle systems varies considerably depending on

8772-506: The relatively homogeneous cut surface of an adult prostate in no way resembled "lobes" and thus led to the description of "zones". Prostate cancer was first described in a speech to the Medical and Chiurgical Society of London in 1853 by surgeon John Adams and increasingly described by the late 19th century. Prostate cancer was initially considered a rare disease, probably because of shorter life expectancies and poorer detection methods in

8874-439: The same contribution to semen as in other mammals. The structure of the prostate varies, ranging from tubuloalveolar (as in humans) to branched tubular . The gland is particularly well developed in carnivorans and boars, though in other mammals, such as bulls, it can be small and inconspicuous. In other animals, such as marsupials and small ruminants , the prostate is disseminate, meaning not specifically localisable as

8976-416: The smooth muscle of the vas deferens and seminal vesicles, following stimulation, primarily of the glans penis . Stimulation sends nerve signals via the internal pudendal nerves to the upper lumbar spine ; the nerve signals causing contraction act via the hypogastric nerves . After traveling into the urethra, the seminal fluid is ejaculated by contraction of the bulbocavernosus muscle . The secretions of

9078-436: The treatment of the diseases of the prostate gland" by Everard Home in 1811, was important in the history of the prostate by describing and naming anatomical parts of the prostate, including the median lobe. The idea of the five lobes of the prostate was popularized following anatomical studies conducted by American urologist Oswald Lowsley in 1912. John E. McNeal first proposed the idea of "zones" in 1968; McNeal found that

9180-458: The upper part is largest and becomes the urinary bladder , and the lower part then changes depending on the biological sex of the embryo. The prostatic part of the urethra develops from the middle, pelvic, part of the urogenital sinus, which is of endodermal origin. Around the end of the third month of embryonic life, outgrowths arise from the prostatic part of the urethra and grow into the surrounding mesenchyme . The cells lining this part of

9282-406: The urethra differentiate into the glandular epithelium of the prostate. The associated mesenchyme differentiates into the dense connective tissue and the smooth muscle of the prostate. Condensation of mesenchyme , urethra , and Wolffian ducts gives rise to the adult prostate gland, a composite organ made up of several tightly fused glandular and non-glandular components. To function properly,

9384-602: The urethral wall. This means the urethra , a compressible tube used for urination, runs through the middle of the prostate; enlargement of the prostate can constrict the urethra so that urinating becomes slow and painful. Prostatic secretions vary among species. They are generally composed of simple sugars and are often slightly alkaline. In eutherian mammals, these secretions usually contain fructose . The prostatic secretions of marsupials usually contain N-Acetylglucosamine or glycogen instead of fructose. Because

9486-429: The urge to empty occurs, but can hold considerably more. The Latin phrase for "urinary bladder" is vesica urinaria , and the term vesical or prefix vesico- appear in connection with associated structures such as vesical veins . The modern Latin word for "bladder" – cystis – appears in associated terms such as cystitis (inflammation of the bladder). In humans, the bladder is a hollow muscular organ situated at

9588-453: The urine ; a physical medical examination may be otherwise normal, except in late disease. Bladder cancer is most often due to cancer of the cells lining the ureter, called transitional cell carcinoma , although it can more rarely occur as a squamous cell carcinoma if the type of cells lining the urethra have changed due to chronic inflammation, such as due to stones or schistosomiasis . Investigations performed usually include collecting

9690-590: The urine, and identify its antibiotic sensitivities . Sometimes, additional investigations may be requested. These might include testing the function of the kidneys by assessing electrolytes and creatinine ; investigating for blockages or narrowing of the renal tract with an ultrasound , and testing for an enlarged prostate with a digital rectal examination . Urinary tract infections or cystitis are treated with antibiotics , many of which are consumed by mouth . Serious infections may require treatment with intravenous antibiotics. Interstitial cystitis refers to

9792-476: The urinogenital ducts and the rectum both empty into the organ called the cloaca . In some reptiles, a midventral wall in the cloaca opens into a urinary bladder. The urinary bladder exists in all species of turtle and tortoise and most species of lizard. Monitor lizards , the legless lizards , snakes, alligators, and crocodiles do not have urinary bladders. Many turtles, tortoises, and lizards have proportionally very large bladders. Charles Darwin noted that

9894-502: The urinogenital passage and urinary bladder. The only mammals in which this does not take place are the platypus and the spiny anteater , both of which retain the cloaca into adulthood. The mammalian bladder is an organ that regularly stores a hyperosmotic concentration of urine. It therefore is relatively impermeable and has a multi-layer epithelium. The urinary bladders of cetaceans (whales and dolphins) are proportionally smaller than those of land-dwelling mammals. In all reptiles,

9996-441: The uterus and anterior to the vagina; thus its maximum capacity is lower than in males. It is separated from the uterus by the vesico-uterine pouch . In infants and young children the urinary bladder is in the abdomen even when empty. Urine is excreted by the kidneys and flows into the bladder through the ureters , where it is stored until urination (micturition). Urination involves coordinated muscle changes involving

10098-495: The variation in descriptions and definitions of lobes, the zone classification is used more predominantly. The prostate has been described as consisting of three or four zones. Zones are more typically able to be seen on histology , or in medical imaging , such as ultrasound or MRI . The "lobe" classification describes lobes that, while originally defined in the fetus, are also visible in gross anatomy, including dissection and when viewed endoscopically. The five lobes are

10200-567: Was describing what was considered to be a pair of organs (not the single two-lobed organ), and the Latin term prostatae that was used was a mistranslation of the term for the Ancient Greek word used to describe the seminal vesicles , parastatai ; although it has been argued that surgeons in Ancient Greece and Rome must have at least seen the prostate as an anatomical entity. The term prostatae

10302-399: Was first developed in the early 20th century and initially consisted of intraprostatic radium implants. External beam radiotherapy became more popular as stronger X-ray radiation sources became available in the middle of the 20th century. Brachytherapy with implanted seeds (for prostate cancer) was first described in 1983. Systemic chemotherapy for prostate cancer was first studied in

10404-565: Was taken rather than the grammatically correct prostator (singular) and prostatores (plural) because the gender of the Ancient Greek term was taken as female, when it was in fact male. The fact that the prostate was one and not two organs was an idea popularised throughout the early 18th century, as was the English language term used to describe the organ, prostate , attributed to William Cheselden . A monograph , "Practical observations on

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