- Urinary bladder
Name = Urinary bladder
Latin = vesica urinaria
GraySubject = 255
GrayPage = 1227
Caption = Urinary system.
Caption2 = Bladder
Width = 300
Superior vesical artery Inferior vesical artery Umbilical artery Vaginal artery
Vesical venous plexus
Vesical nervous plexus
external iliac lymph nodes, internal iliac lymph nodes
MeshName = Bladder
MeshNumber = A05.810.161
DorlandsPre = v_07
DorlandsSuf = 12855244
anatomy, the urinary bladder is a hollow, muscular, and distensible (or elastic) organ that sits on the pelvic floorin mammals. It is the organ that collects urineexcreted by the kidneys prior to disposal by urination. Urine enters the bladder via the ureters and exits via the urethra.
In males, the bladder is superior to the
prostate, and separated from the rectumby the rectovesical excavation.
In females, the bladder is separated from the
uterusby the vesicouterine excavation.
detrusor muscleis a layer of the urinary bladder wall made of smooth musclefibers arranged in spiral, longitudinal, and circular bundles. When the bladder is stretched, this signals the parasympatheticnervous system to contract the detrusor muscle. This encourages the bladder to expel urinethrough the urethra.
For the urine to exit the bladder, both the
autonomically controlled internal sphincterand the voluntarily controlled external sphincter must be opened. Problems with these muscles can lead to incontinence. If the amount of urine reaches 100% of the urinary bladder volume, the voluntary sphincter becomes involuntary and the urine will be ejected instantly, although it is possible to "hold yourself" in order to prevent urination. The body cannot afford having the urinary bladder burst.
The urinary bladder usually holds 400–620 mL of urine, but it can hold twice this without rupturing if, for example, the outflow is obstructed.
The desire to urinate usually starts when the bladder reaches around 75% of its working volume. If the subject is distracted the desire can fade and return with more urgency as the bladder continues to fill.
Since the urinary bladder has a
transitional epithelium, compared to the intestine mucosa, the urinary bladder does not produce mucus. [ [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WKP-4PMK2X4-Y&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=89f27dee46151805e831331aace3a19f T . Chin , C . Liu , H . Tsai , C . Wei. Vaginal reconstruction using urinary bladder flap in a patient with cloacal malformation] ]
The fundus of the urinary bladder is the base of the bladder, formed by the posterior wall. It is
lymphaticallydrained by the external iliac lymph nodes. The peritoneum lies superior to the fundus.
Disorders of or related to the bladder include:
Overactive bladder, a condition which affects a large number of people.
Bladder sphincter dyssynergia, a condition in which the sufferer cannot coordinate relaxation of the urethra sphincter with the contraction of the bladder muscles
Hematuria, or presence of blood in the urine, is a reason to seek medical attention without delay, as it is a symptom of bladder cancer as well as bladder and kidney stones.
Bladder exstrophyjakes is hugee.
Besides its normal use to the possessor, animal bladders (usually
pigbladders) have been used to make balls (such as footballs, and even a musical instrument, the bumbass.
UrodynamicsThe study of the functional aspects of the detrusor muscle.
Uvula of urinary bladder
Urinary bladder disease
* "Urinary Bladder"
* - "Mammal, bladder (LM, Medium)"
* - "The Female Pelvis: The Urinary bladder"
* - "The Male Pelvis: The Urinary bladder"
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