"Bladder" redirects here. For other uses, see bladder (disambiguation).
| Urinary bladder |
1. Human urinary system: 2. Kidney, 3. Renal pelvis, 4. Ureter, 5. Urinary bladder, 6. Urethra. (Left side with frontal section)
7. Adrenal gland
Vessels: 8. Renal artery and vein, 9. Inferior vena cava, 10. Abdominal aorta, 11. Common iliac artery and vein
With transparency: 12. Liver, 13. Large intestine, 14. Pelvis |
| Details |
| Precursor |
urogenital sinus |
| System |
Urinary system |
| Artery |
Superior vesical artery
Inferior vesical artery
Umbilical artery
Vaginal artery |
| Vein |
Vesical venous plexus |
| Nerve |
Vesical nervous plexus |
| Identifiers |
| Latin |
vesica urinaria |
| MeSH |
A05.810.161 |
Dorlands
/Elsevier |
Urinary bladder |
| TA |
A08.3.01.001 |
| FMA |
15900 |
| Anatomical terminology
[edit on Wikidata]
|
The urinary bladder is a hollow muscular organ that collects urine from the kidneys before disposal by urination. A hollow[1] muscular, and distensible (or elastic) organ, the bladder sits on the pelvic floor. Urine enters the bladder via the ureters and exits via the urethra. The typical human bladder capacity is between 300 and 500 mL.[2][3]
Contents
- 1 Structure
- 1.1 Histology
- 1.2 Detrusor muscle
- 1.3 Lymphatic supply
- 1.4 Nerve supply
- 1.5 Development
- 2 Function
- 3 Clinical significance
- 4 Other animals
- 5 Additional images
- 6 See also
- 7 References
- 8 External links
Structure
Anatomy of the female bladder, showing transitional epithelium as well as part of the wall in a histological cut-out.
The bladder is a hollow muscular organ situated at the base of the pelvis. Urine collects in the bladder from the two ureters, which open into the bladder at its back and connect to the kidneys. Urine leaves the bladder via the urethra, a single muscular tube which ends in the urethral orifice. Anatomically, the bladder is divided into a fundus at the top, two ureteric orifices, and an opening for the urethra which surrounds the trigone of the bladder. In men, the prostate gland lies outside the opening for the urethra.
The bladder is situated below the peritoneal cavity near the pelvic floor. In men, it lies in front of the rectum, separated by a space. In women, it lies in front of the uterus.
Histology
The urinary bladder is lined with transitional epithelium. It does not produce mucus.[4] The internal lining of the bladder wall is termed the urothelium and lamina propria, and this layer is thought to regulate some aspects of the overall bladder physiology in response to stimuli such as stretch during filling.[5]
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Vertical section of bladder wall.
-
Layers of the urinary bladder wall and cross section of the detrusor muscle.
Detrusor muscle
The detrusor muscle is a layer of the urinary bladder wall made of smooth muscle fibers arranged in spiral, longitudinal, and circular bundles. When the bladder is stretched, this signals the parasympathetic nervous system to contract the detrusor muscle. This encourages the bladder to expel urine through the urethra. A meta-analysis on the effect of voiding position on urodynamics in males found that sitting down allows for improved contraction of the detrusor muscle.[6]
Lymphatic supply
The fundus of the bladder is lymphatically drained by the external iliac lymph nodes.
Nerve supply
The bladder receives motor innervation from both sympathetic fibers, most of which arise from the hypogastric plexuses and nerves, and parasympathetic fibers, which come from the pelvic splanchnic nerves and the inferior hypogastric plexus.[7]
Sensation from the bladder is transmitted to the central nervous system (CNS) via general visceral afferent fibers (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.[7]
For the urine to exit the bladder, both the autonomically controlled internal sphincter and the voluntarily controlled external sphincter must be opened. Problems with these muscles can lead to incontinence.[8]
Development
The human urinary bladder is derived from the urogenital sinus and, it is initially continuous with the allantois. 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 rectovesical excavation. 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 uterus by the vesicouterine excavation. In infants and young children, the urinary bladder is in the abdomen even when empty.[9]
Function
Main article: Urination
Urine, excreted by the kidneys, collects in the bladder before disposal by urination. The urinary bladder usually holds 300-350 ml of urine. 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.[10]
Clinical significance
Main article: Urinary bladder disease
Urinary bladder (black butterfly-like shape) and hyperplastic prostate (BPH) visualized by Medical ultrasonography technique.
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 overactive bladder is when a person urinates more than eight times per day,[11] though there can be other causes of urination frequency.[citation needed] Though both urinary frequency and volumes have been shown to have a circadian rhythm, meaning day and night cycles,[12] it is not entirely clear how these are disturbed in the overactive bladder.
A diverticulum of the bladder
Disorders of or related to the bladder include:
- Bladder cancer
- Bladder exstrophy
- Bladder infection
- Bladder spasm
- Bladder sphincter dyssynergia, a condition in which the sufferer cannot coordinate relaxation of the urethra sphincter with the contraction of the bladder muscles
- Bladder stones
- Cystitis
- 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
- Interstitial Cystitis
- Overactive bladder, a condition that affects a large number of people
- Paruresis
- Urinary incontinence
- Urinary retention
Other animals
Bladders occur throughout much of the animal kingdom, but are very diverse in form[further explanation needed] and in some cases are not homologous with the urinary bladder in humans.[citation needed] The pig bladder is very similar to the human bladder.
Additional images
-
Vertical section of bladder, penis, and urethra.
-
The bladder can be seen highlighted in yellow in the illustration.
See also
- Artificial urinary bladder
- Bladder augmentation
- Neurogenic bladder
- Ureterocele
- Urodynamics
- Uvula of urinary bladder
- Vesicouretic reflux
References
- ^ Howard A. Werman, Keith J. Karren.[full citation needed]
- ^ Boron, Walter F.; Boulpaep, Emile L. (2016). Medical Physiology. 3: Elsevier Health Sciences. p. 738. ISBN 9781455733286. Retrieved 1 June 2016.
- ^ Walker-Smith, John; Murch, Simon (1999). Cardozo, Linda, ed. Diseases of the Small Intestine in Childhood (4 ed.). CRC Press. p. 16. ISBN 9781901865059. Retrieved 1 June 2016.
- ^ Chin T, Liu , Tsai H, Wei C (September 2007). "Vaginal reconstruction using urinary bladder flap in a patient with cloacal malformation". Journal of Pediatric Surgery 42 (9): 1612–5. doi:10.1016/j.jpedsurg.2007.04.040. PMID 17848259.
- ^ Moro C, Uchiyama J, Chess-Williams R (December 2011). "Urothelial/lamina propria spontaneous activity and the role of M3 muscarinic receptors in mediating rate responses to stretch and carbachol". Urology. 76 (6): 1442.e9–15. doi:10.1016/j.urology.2011.08.039. PMID 22001099.
- ^ de Jong, Y; Pinckaers, JH; Ten Brinck, RM; Lycklama À Nijeholt, AA; Dekkers, OM (2014). "Urinating Standing versus Sitting: Position Is of Influence in Men with Prostate Enlargement. A Systematic Review and Meta-Analysis.". PLOS ONE 9 (7): e101320. doi:10.1371/journal.pone.0101320. PMC 4106761. PMID 25051345.
- ^ a b Moore, Keith; Anne Agur (2007). Essential Clinical Anatomy, Third Edition. Lippincott Williams & Wilkins. pp. 227–228. ISBN 0-7817-6274-X.
- ^ "Urinary Incontinence - Causes". NHS. Retrieved 2013-08-21.
- ^ Moore, Keith L.; Dalley, Arthur F (2006). Clinically Oriented Anatomy (5th ed.). Lippincott Williams & Wilkins.
- ^ Marieb, Mallatt. "23". Human Anatomy (5th ed.). Pearson International. p. 700.
- ^ "Overactive Bladder". Cornell Medical College. Retrieved 2013-08-21.
- ^ Negoro, Hiromitsu (2012). "Involvement of urinary bladder Connexin43 and the circadian clock in coordination of diurnal micturition rhythm". doi:10.1038/ncomms1812.
External links
|
Wikimedia Commons has media related to Urinary bladder. |
- Histology at KUMC epithel-epith09 "Urinary Bladder"
- Anatomy photo: Urinary/mammal/bladder/bladder1 - Comparative Organology at University of California, Davis — "Mammal, bladder (LM, Medium)"
- Virtual Slidebox at Univ. Iowa Slide 445
- Anatomy photo:43:07-0100 at the SUNY Downstate Medical Center — "The Female Pelvis: The Urinary bladder"
- Anatomy photo:44:04-0103 at the SUNY Downstate Medical Center — "The Male Pelvis: The Urinary bladder"
- Bladder (ISSN 2327-2120) — An open-access journal on bladder biology and diseases.
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Human systems and organs
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| Musculoskeletal |
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Skeletal system
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- Bone
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Muscular system
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Cardiovascular system
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- peripheral
- Artery
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Lymphatic system
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- primary
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- CNS equivalent
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- Skin
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- Mouth
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| Urinary system |
- Genitourinary system
- Kidney
- Ureter
- Bladder
- Urethra
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| Reproductive system |
- Female
- Uterus
- Vagina
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- Male
- Scrotum
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- Testicle
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| Endocrine system |
- Pituitary
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- Thyroid
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- Adrenal
- Islets of Langerhans
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General anatomy: systems and organs, regional anatomy, planes and lines, superficial axial anatomy, superficial anatomy of limbs
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Anatomy of the urinary system
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| Kidneys |
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Layers
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- Fascia
- Capsule
- Cortex
- Medulla
- sinus
- pyramids
- medullary interstitium
- Lobe
- Cortical lobule
- Medullary ray
- Nephron
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Circulation
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- Arteries
- Renal artery
- segmental
- interlobar
- arcuate
- interlobular
- afferent
- Veins
- Renal vein
- Peritubular capillaries
- Vasa recta
- arcuate
- interlobar
- efferent
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Nephron
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Renal corpuscle
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- Glomerulus
- Bowman's capsule
- Glomerular basement membrane
- Podocyte
- Filtration slits
- Mesangium
- Intraglomerular mesangial cell
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Renal tubule
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- Proximal convoluted tubule
- Loop of Henle
- Descending
- Thin ascending
- Thick ascending
- Distal convoluted tubule
- Connecting tubule
- Tubular fluid
- Renal papilla
- Minor calyx
- Major calyx
- Renal pelvis
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Juxtaglomerular apparatus
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- Macula densa
- Juxtaglomerular cells
- Mesangium
- Extraglomerular mesangial cell
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| Ureters |
- Orifice of ureter
- Ureteropelvic junction
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| Bladder |
- Apex
- Uvula
- Neck
- Median umbilical ligament
- Muscular layer
- Mucosa
- Submucosa
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| Urethra |
- Urethral sphincters
- External sphincter
- Internal sphincter
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| Authority control |
- GND: 4072323-9
- NDL: 00560840
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