Bowman's capsule

Bowman's capsule

Infobox Anatomy
Name = Bowman's capsule
Latin = capsula glomeruli
GraySubject = 253
GrayPage = 1222


Caption = Glomerulus. (Bowman's capsule not labeled, but visible at top.)


Caption2 = Glomerulus is red; Bowman's capsule is green.
Precursor = Metanephric blastema
System =
Artery =
Vein =
Nerve =
Lymph =
MeshName = Bowman+Capsule
MeshNumber =
DorlandsPre = c_07
DorlandsSuf = 12211408

The Bowman's capsule (other names: capsula glomeruli, glomerular capsule) is a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney. A glomerulus is enclosed in the sac. Fluids from blood in the glomerulus are collected in the Bowman's capsule (i.e., glomerular filtrate) and further processed along the nephron to form urine. This process is known as ultrafiltration.

Anatomy

Outside the capsule, there are two "poles":
* The vascular pole is the side with the afferent arteriole and efferent arteriole.
* the urinary pole is the side with the proximal convoluted tubule.

Inside the capsule, the layers are as follows, from outside to inside:

Physiology

The process of filtration of the blood in the Bowman's capsule is ultrafiltration (or glomerular filtration), and the normal rate of filtration is 125 ml/min, equivalent to ten times the blood volume daily.

Any proteins under roughly 30 kilodaltons can pass freely through the membrane, although there is some extra hindrance for negatively charged molecules due to the negative charge of the basement membrane and the podocytes.

Any small molecules such as water, glucose, salt (NaCl), amino acids, and urea pass freely into Bowman's space, but cells, platelets and large proteins do not.

As a result, the filtrate leaving the Bowman's capsule is very similar to blood plasma in composition as it passes into the proximal convoluted tubule.

Clinical significance

Measuring the glomerular filtration rate (GFR) is a diagnostic test of kidney function.

A decreased GFR may be a sign of renal failure.

A number of diseases can result in various problems within the glomerulus. Examples include acute proliferative (endocapillary) glomerulonephritis, mesangioproliferative glomerulonephritis, mesangiocapillary (membranoproliferative) glomerulonephritis, acute crescentic glomerulonephritis, focal segmental glomerulonephritis, and diabetic glomerulosclerosis.

Eponym

Bowman's capsule is named after Sir William Bowman (1816-1892), a British surgeon and anatomist.

Together with the glomerulus it is known as a renal corpuscle, or a Malpighian corpuscle, named after Marcello Malpighi (1628-1694), an Italian physician and biologist. This name is not used widely anymore, probably to avoid confusion with a Malpighian corpuscle in the spleen.

ee also

* mesangium


=Additional

References

External links

*
* [http://faculty.ircc.edu/faculty/tfischer/images/Bowman's%20capsule.jpgDiagram at ircc.edu]


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Look at other dictionaries:

  • Bowman's capsule — 1882, named for English surgeon William Bowman (1816 1892) …   Etymology dictionary

  • Bowman's capsule — Bow·man s capsule .bō mənz n a thin membranous double walled capsule surrounding the glomerulus of a vertebrate nephron through which glomerular filtrate passes to the proximal convoluted tubule called also capsule of Bowman, glomerular capsule… …   Medical dictionary

  • Bowman's capsule — noun Etymology: Sir William Bowman died 1892 English surgeon Date: circa 1860 a thin membranous double walled capsule surrounding the glomerulus of a vertebrate nephron …   New Collegiate Dictionary

  • Bowman's capsule — /boh meuhnz/, Anat. a membranous, double walled capsule surrounding a glomerulus of a nephron. Cf. Malpighian corpuscle. [1880 85; named after Sir William Bowman (1816 92), English surgeon] * * * …   Universalium

  • Bowman's capsule — Bow′man s cap′sule [[t]ˈboʊ mənz[/t]] n. anat. a membranous, double walled capsule surrounding a glomerulus of a nephron • Etymology: 1880–85; after Sir William Bowman (1816–92), English surgeon …   From formal English to slang

  • Bowman's capsule — the cup shaped end of a nephron, which encloses a knot of blood capillaries (glomerulus). It is the site of primary filtration of the blood into the kidney tubule. [Sir W. P. Bowman (1816–92), British physician] …   The new mediacal dictionary

  • Bowman's capsule — noun A cup like sac at the beginning of the tubular component of a nephron in the mammalian kidney. Syn: capsula glomeruli, glomerular capsule …   Wiktionary

  • Bowman's capsule — noun thin double membrane surrounding the glomerulus of a nephron • Syn: ↑glomerular capsule, ↑capsula glomeruli • Hypernyms: ↑membrane, ↑tissue layer • Part Holonyms: ↑malpighian body, ↑ …   Useful english dictionary

  • Bowman's capsule — the cuplike proximal end of a kidney tubule surrounding a glomerulus …   Dictionary of ichthyology

  • Bowman — may refer to:Places;Bowman Island* Bowman Peninsula;Australia * Division of Bowman, an electoral district in the Australian House of Representatives * Bowman Park, South Australia;Canada * Bowmanville, Ontario;United States * Bowman, Georgia *… …   Wikipedia

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