Kidney

Neelam Maurya

8 years ago

KIDNEY

Kidney is a retroperitoneal organ, lying on the upper part of posterior abdominal wall.
Each kidney is 11cm long, 6cm wide & 3cm thick with average weight in male is 150gm & in female is 135gm.
Bean shaped with two poles (upper & lower), two borders (medial & lateral) & two surfaces (anterior & posterior).
Lateral border is convex.
Medial border is concave& shows a depression in middle part called hilus (or hilum).
Hilum contains following structures from anterior or posterior:- renal vein, renal artery, & renal pelvis.
Hilum is 5 cm away from L1 spine on the transpyloric plane.

DEVELOPMENT:

The mammalian kidney develops from intermediate mesoderm in Sacral region.
Ureteric bud (mesonephros) arise from mesonephric duct and gives rise to collecting system of kidney (renal pelvis, major and minor calyces, collecting tubule) and ureter.
Metanephric mesoderm (blastema or metanephors) arise from nephrogenic cord which in turn is derived from intermediate mesoderm. It gives rise to excretory unit (nephron), i.e. glomeruli, PCT, Loop of henle and DCT.
Kidney development, also called nephrogenesis, proceeds through a series of three successive developmental phases: the pronephros, mesonephros, and metanephros.

Excretory tubules (All parts of nephron)	Arises from metanephros
Collecting part (Pelves, calyces, ureter)	Arises from Ureteric bud (Mesonephros)

The neonatal kidney achieves concentrating ability equivalent to adult’s kidney by 1year.

LOCATION:

Located high in the abdominal cavity, one on each side of the spine, and lie in a retroperitoneal position at a slightly oblique angle.
Right kidney being slightly lower and smaller than the left, and related only to 12th rib.
The left kidney is approximately at the vertebral level T12 to L3.
The right kidney sits just below the diaphragm and posterior to the liver.
The left sits below the diaphragm and posterior to the spleen.
On top of each kidney is an adrenal gland.

RELATIONS:

Anterior Relations:

Left Kidney	Right Kidney
Supra – renal gland Small Intestine (jejunum) & Stomach Spleen & Its vessels, Splenic flexure Descending colon, Pancreas	Supra – renal gland Jejunum Second part of duodenum Hepatic flexure of colon & Liver. Hepatic & intestinal surfaces are covered by peritoneum.

Right kidney & liver are separated from each other by hepatorenal pouch of Morison.

Posterior Relations (of both kidneys):

Muscles(4)	Nerves(3)	Ligaments(2)	Vessel & Rib (each)
Diaphragm Psoas major Quadratus lumborum Transversus abdominis	Subcostal.N Iliohypogastric.N Ilioinguinal. N	Medial arcuate Lateral arcuate	Subcostal Vessels 12th rib- upper pole of right kidney Left kidney is related to 11th & 12th rib

Medial borderof each kidney is related to suprarenal gland above the hilus & ureter below the hilus.

Lateral border of right kidney is related to the right lobe of liver & hepatic flexure of colon.

Exam Question

Right kidney is lower & distal than the left kidney
Right kidney is related to duodenum
The neonatal kidney achieves concentrating ability equivalent to adult’s kidney by 1year
Development of human kidney begins in Sacral region
Between the renal pyramids are projections of cortex called renal columns (or Bertin columns).
Extent of kidney is from T12-L3
Kidney is supported by perirenal fat, renal fascia, and pararenal fat
Renal angle lies between 12th rib and lateral border of sacrospinalis
Excretory system of kidney is derived from Metanephros
Kidney develops from Metanephros, Mesonephric duct(Mesonephros), Blastema.
Collecting part of kidney develops from mesonephros or Ureteric bud

Don’t Forget to Solve all the previous Year Question asked on Kidney