The renal pelvis or pelvis of the kidney is the funnel-like dilated part of the
ureter in the
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
. It is formed by the covnvergence of the
major calyces, acting as a funnel for urine flowing from the major calyces to the ureter. It has a
mucous membrane and is covered with
transitional epithelium and an underlying
lamina propria
The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosae, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenit ...
of loose-to-dense
connective tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...
.
The renal pelvis is situated within the
renal sinus alongside the other structures of the renal sinus.
The renal pelvis is the location of several kinds of
kidney cancer and is affected by infection in
pyelonephritis
Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications ...
.
Clinical significance
The renal pelvis is the location of several kinds of
kidney cancer and is affected by infection in
pyelonephritis
Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications ...
. A large
"staghorn" kidney stone may block all or part of the renal pelvis.
The size of the renal pelvis plays a major role in the
grading of hydronephrosis. Normally, the anteroposterior diameter of the renal pelvis is less than 4 mm in
fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...
es up to 32 weeks of
gestational age and 7 mm afterwards.
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in: In adults, 13% of the normal population have a transverse pelvic diameter of over 10 mm.
Etymology and pronunciation
Like the
bony pelvis, the renal pelvis () gets its English name via
New Latin from the older
Latin
Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
word ''
pelvis'', "basin", as in "
wash basin".
In both cases the name reflects the shape of the structure, and in the case of the renal pelvis, it also reflects the function. The name reflects that each renal pelvis collects
urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Cellul ...
from the
calyces and funnels it into the
ureter like a wash basin collects
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
and funnels it into a
drain pipe. The renal pelvis is occasionally called the pyelum (from Greek πύελος ''pýelos'', "trough", ‘anything hollow’), and the
combining form
Neoclassical compounds are compound words composed from combining forms (which act as affixes or stems) derived from classical Latin or ancient Greek roots. New Latin comprises many such words and is a substantial component of the technical an ...
''
pyelo-'' denotes the renal pelvis (''pyelo-'' is not to be confused with ''
pyo-''). The words ''
infundibulum'' and ''
choana
The choanae (singular choana), posterior nasal apertures or internal nostrils are two openings found at the back of the nasal passage between the nasal cavity and the throat in tetrapods, including humans and other mammals (as well as crocodili ...
'' are other words for funnel-shaped cavities (which medical English got from the Latin and Greek words for "funnel", respectively), and the renal pelvis is sometimes called the renal infundibulum. The form ''*renal choana''
is logical but is not used.
Additional images
File:Gray1118.png, Depiction of the developing renal pelvis.
File:Slide17iii.JPG, Cutaway section of a preserved human kidney
See also
*
Renal sinus
*
Pyelectasis Pyelectasis is a dilation of the renal pelvis. It is a relatively common ultrasound finding in fetuses and is three times more common in male fetuses. In most cases pyelectasis resolves normally, having no ill effects on the baby. The significance ...
, the dilation of the renal pelvis
References
External links
* —"Section of the kidney, anterior view."
*
* —"Mammal, renal pelvis (Gross, Medium)"
* —"Mammal, renal pelvis (LM, Medium)"
{{Authority control
Kidney anatomy