NEPHROLOGY
NEPHROTIC SYNDROME
calculi may need to be broken up before
removal. Other methods of removal are
pyelolithotomy
and
lithotripsy
.
nephrology
The medical speciality con-
cerned with the normal functioning of
the
kidneys
and with the causes, diag-
nosis, and treatment of kidney disease.
Methods of investigating the kidneys
include kidney
biopsy
,
kidney function
tests
,
and
kidney imaging
techniques
such as
ultrasound scanning
and
intra-
venous urography
. Treatment of kidney
disorders
may
involve
drugs
and
surgery and, in advanced cases,
dialysis
or a
kidney transplant
.
nephron
The microscopic unit of the
kidney that consists of a glomerulus (a
filtering funnel made up of a cluster of
capillaries) and a tubule. There are
about
1
million nephrons in each kid-
ney. The nephrons filter waste products
from the blood and modify the amount
of salt and water excreted in urine,
according to the body's needs. This pro-
cess involves filtration of blood in the
glomerulus followed by further process-
ing as the filtrate flows through the
various parts of the tubule - the proxi-
mal convoluted tubule, loop of Henle,
and the distal convoluted tubule.
nephropathy
A term for any disease of
or damage to the
kidneys
.
Obstructive nephropathy refers to kid-
ney damage caused by a urinary tract
calculus
(stone), a tumour, scar tissue,
or pressure from an organ that is block-
ing the flow of urine and creating back
pressure within the kidney.
Reflux nephropathy refers to kidney
damage caused by backflow of urine
from the bladder towards the kidney. It
is caused by failure of the valve mecha-
nism at the lower end of the ureter.
Toxic nephropathy refers to damage
caused by various poisons or minerals
(such as carbon tetrachloride or lead).
nephrosclerosis
Hardening of the art-
erioles and arteries of the
kidney.
nephrosis
See
nephrotic syndrome
.
nephrostomy
The introduction of a
small tube into the
kidney
to drain urine
to the abdominal surface, bypassing the
ureter and bladder.
Nephrostomy is
sometimes performed after an operation
on the ureter or kidney-ureter junction.
nephrotic syndrome
A collection of
symptoms and signs resulting from
damage to the glomeruli (filtering units
of the
kidney
), causing severe
proteinuria
(loss of protein from the bloodstream
into the urine). The
syndrome may be
a result of
diabetes
mellitus
,
amyloido-
sis
(accumulation in
tissues of an abnor-
mal protein called
amyloid),
glomeru-
lonephritis
,
severe
hypertension
, reac-
tions to poisons,
and adverse reac-
tions to drugs.
The main symp-
tom is swelling of
the legs and face
due to
oedema
. Al-
so, fluid may collect
in the chest cavity,
resulting in
pleural
effusion
, or in the
abdomen, causing
ascites
.
Diarrhoea,
lethargy, and
ano-
rexia
may occur.
NEPHRON
Artery
Vein
Capillaries
Glomerular
capsule
Proximal
convoluted
5
L
tubule
Glomerulus
Urine
collecting
duct
Loop of Henle
N
393
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