Bladder location and associated structures in the male In humans, the bladder is a hollow muscular organ situated at the. Collects in the bladder, fed from the two that connect the bladder with the. Urine leaves the bladder via the, a single muscular tube ending in an opening – the, where it exits the body. Anatomists divide the bladder into. a broad.
The urinary bladder is a muscular sac in the pelvis, just above and behind the pubic bone. When empty, the bladder is about the size and shape of a pear. Urine is made in the kidneys and travels. Genetics and family history. People with this disease also have a higher risk of bladder cancer. Lynch syndrome (also known as hereditary non-polyposis colorectal cancer, or HNPCC) is linked mainly to colon and endometrial cancer. People with this syndrome might also have an increased risk of bladder cancer (as well as other cancers of the urinary tract).
a body. an apex.
a neck The apex (prev. Vertex) is directed forward toward the upper part of the, and from there the continues upward on the back of the anterior abdominal wall to the. The is carried by it from the apex on to the to form the. The neck of the bladder is the area at the base of the trigone that surrounds the that leads to the urethra. In males the neck of the urinary bladder is adjacent to the. The three openings, two, and the internal urethral orifice mark the triangular area called the.
These openings have mucosal flaps in front of them that act as valves in preventing the backflow of urine into the ureters, known as. 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 a area that forms the floor of 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. In men, the lies outside the opening for the urethra.
The middle lobe of the prostate causes an elevation in the mucous membrane behind the internal urethral orifice called the uvula of urinary bladder. The uvula can enlarge when the prostate becomes enlarged. The bladder is situated below the near the and behind the. In men, it lies in front of the rectum, separated by the, and is supported by fibres of the and of the prostate gland. In women, it lies in front of the, separated by the, and is supported by the elevator ani and the upper part of the vagina. The wall of the urinary bladder is normally 3–5 mm thick.
When well distended, the wall is normally less than 3 mm. The inner walls have a series of ridges, thick mucosal folds known as that allow for the expansion of the bladder. The Latin phrase for 'urinary bladder' is vesica urinaria, and the term vesical or prefix vesico - appear in connection with associated structures such as. The modern Latin word for 'bladder' - cystis - appears in associated terms such as (inflammation of the bladder). Microanatomy The outside of the bladder is protected by a. The bladder wall itself is.
The inner side of the bladder is lined with a consisting of a surface that protects the cells beneath it from urine, the (a form of ), a, and the. The mucosal lining also offers a urothelial barrier against the passing of infections. Anatomy of the male bladder, showing transitional epithelium and part of the wall in a histological cut-out. Detrusor muscle The is a layer of the urinary bladder wall made of arranged in spiral, longitudinal, and circular bundles.
In the bladder signal the nervous system to stimulate the in the detrusor to contract the muscle when the bladder is extended. This encourages the bladder to expel urine through the urethra.
The main receptor activated is the, although are also involved and whilst outnumbering the M3 receptors they are not so responsive. The main relaxant pathway is via the pathway, activated. The detrusor muscle is unusually able to change its length.
It can also contract for a long time whilst, and it stays relaxed whilst the bladder is filling. The urothelium and lamina propria (also termed the bladder mucosa) line the inside of the detrusor muscle, and can release regulators to influence general contractility of the detrusor muscle, maintain normal bladder tone, and potentially mediate bladder diseases such as overactive bladder. Blood- and lymph-supply The bladder is supplied by the and drained by the. The supplies blood to the upper part of the bladder. The lower part of the bladder is supplied by the in males and by the in females, both of which are branches of the.
In females, the provides additional blood supply. Venous drainage begins in a network of small vessels on the lateral and posterior surfaces of the bladder, which coalesce and pass backwards along the lateral ligaments of the bladder into the.
The drained from the bladder begins in a series of networks throughout 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. Nerve supply The bladder receives motor innervation from both sympathetic fibers, most of which arise from the and and nerves, and from parasympathetic fibers, which come from the. Sensation from the bladder is transmitted to the (CNS) via (GVA).
GVA fibers on the superior surface follow the course of the sympathetic efferent nerves back to the CNS, while GVA fibers on the inferior portion of the bladder follow the course of the parasympathetic efferents. For the urine to exit the bladder, both the controlled internal and the controlled external sphincter must be opened.
Problems with these muscles can lead to. Development The human urinary bladder derives from the, and it is initially continuous with the. The upper and lower parts of the bladder develop separately and join together around the middle part of. At this time the ureters move from the to the trigone. In males, the base of the bladder lies between the rectum and the pubic symphysis. It is superior to the, and separated from the by the. In females, the bladder sits inferior to the uterus and anterior to the vagina; thus its maximum capacity is lower than in males.
It is separated from the by the. In and young children the urinary bladder is in the even when empty. Function. Calcifications on bladder wall caused by urinary is the presence of bacteria in the urine which can indicate a such as. Incontinence and retention Frequent urination can be due to excessive urine production, small bladder capacity, irritability or incomplete emptying. Males with an urinate more frequently. One definition of an is when a person urinates more than eight times per day.
An overactive bladder can often cause. Though both urinary frequency and volumes have been shown to have a circadian rhythm, meaning day and night cycles, it is not entirely clear how these are disturbed in the overactive bladder.
Can help to explain the symptoms. An is the condition where there is a difficulty in passing urine and is the main symptom of a. Frequent urination at night may indicate the presence of. Disorders of or related to the bladder include:., a condition in which the sufferer cannot coordinate relaxation of the urethra sphincter with the contraction of the bladder muscles.
Disorders of bladder function may be dealt with surgically, by re-directing the flow of urine or by replacement with an. The volume of the bladder may be increased. May be severe enough to warrant surgery. Cancer. – the most common type is.
Investigation. A of the bladder can help to explain the symptoms. Other animals Reptiles In all reptiles the urinogenital ducts and the both empty into an organ called a.
In some reptiles, a midventral wall in the cloaca may open into a urinary bladder, but not all. It is present in all turtles and tortoises as well as most lizards, but is lacking in the, the. It is absent in the snakes, alligators, and crocodiles.: p. 474 Many turtles, tortoises, and lizards have proportionally very large bladders. Noted that the had a bladder which could store up to 20% of its body weight. Such adaptations are the result of environments such as remote islands and deserts where water is very scarce.: 143 Other desert-dwelling reptiles have large bladders that can store a long-term reservoir of water for up to several months and aid in.
Turtles have two or more accessory urinary bladders, located lateral to the neck of the urinary bladder and dorsal to the pubis, occupying a significant portion of their body cavity. Their bladder is also usually bilobed with a left and right section. The right section is located under the liver, which prevents large stones from remaining in that side while the left section is more likely to have. Amphibians Most aquatic and semi-aquatic amphibians have a membranous skin which allows them to absorb water directly through it.
Some semi-aquatic animals also have similarly permeable bladder membrane. As a result, they tend to have high rates of urine production to offset this high water intake, and have urine which is low in dissolved salts. The urinary bladder assists such animals to retain salts.
Some aquatic amphibian such as do not reabsorb water, to prevent excessive water influx. For land-dwelling amphibians, dehydration results in reduced urine output.: p. 184 The amphibian bladder is usually highly distensible and among some land-dwelling species of frogs and salamanders may account for between 20% and 50% of their total body weight.: p. 184 Fish The gills of most 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 is permeable to water, though this is less true for freshwater dwelling species than saltwater species.: p. 219 Most fish also have an organ called a which is unrelated to the urinary bladder except in its membranous nature. The, and are among 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 and behind the. Mammals All mammals have a urinary bladder. This structure begins as an. In the vast majority, this eventually becomes differentiated into a dorsal part connected to the intestine and a ventral part which becomes associated with the urinogenital passage and urinary bladder.
The only mammals in which this does not take place are the and the 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 multiple epithelial layers. The urinary bladder of the (whales and dolphins) is proportionally smaller than that of land-dwelling mammals. Birds In the whole class of there is no urinary bladder per se.
Although all birds have kidneys, the open directly into a which serves as a reservoir for urine, fecal matter, and eggs. Crustaceans In, the urinary bladder consists of two sets of lateral and central lobes. Additional images.
The kidneys filter the blood and help remove wastes and extra fluid from the body. The kidneys also help control the body's chemical balance. The kidneys are part of the urinary system, which also includes the ureters, bladder, and urethra. Muscle changes and changes in the reproductive system can affect bladder control. AGING CHANGES AND THEIR EFFECTS ON THE KIDNEYS AND BLADDER As you age, your kidneys and bladder change. This can affect their function. Changes in the kidneys that occur with age:.
Amount of kidney tissue decreases. Number of filtering units (nephrons) decreases. Nephrons filter waste material from the blood. Blood vessels supplying the kidneys can become hardened. This causes the kidneys to filter blood more slowly. Changes in the bladder:.
The bladder wall changes. The elastic tissue becomes tough and the bladder becomes less stretchy. The bladder cannot hold as much urine as before. The bladder muscles weaken. The urethra can become blocked. In women, this can be due to weakened muscles that cause the bladder or vagina to fall out of position (prolapse). In men, the urethra can become blocked by an enlarged.
In a healthy aging person, kidney function remains normal. But illness, medicines, and other conditions can affect kidney function. Griebling TL. Aging and geriatric urology.
In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology. Philadelphia, PA: Elsevier; 2016:chap 88. Smith PP, Kuche GA. Aging of the urinary tract. In: Fillit HM, Rockwood K, Young J, eds. Brocklehurst's Textbook of Geriatric Medicine and Gerontology.
Philadelphia, PA: Elsevier; 2017:chap 22. Common clinical sequelae of aging. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. Philadelphia, PA: Elsevier Saunders; 2016:chap 25.
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