Urinary System;
Urinary system consists of a pair of kidneys, ureter, urinary bladder and urethra.
 |
| urinary system |
Kidneys;
*Kidneys are the main organs of Urinary system.
*The right kidney is slightly lower than the left kidney due to the large size of right lobe of liver.
Location; kidneys lie behind peritoneum on posterior abdominal wall on either sides of vertebral column.
Color; Kidneys are reddish brown in color.
Area; Each kidney is about 10cm long and 5cm wide.
Protection; Last two pairs of rib bones of rib cage protect kidneys.
COVERINGS OF KIDNEY;
Both kidneys are covered by four coverings.
i)Fibrous Capsule;
ii)Perirenal Fat
iii)Renal Fascia
iv)Pararenal Fat
Structure of kidney;
*Kidney contain millions of nephrons.
*Structurally it is consist of following structures;
i)Renal Cortex;
Outer portion of kidney is called renal cortex.
*It is dark brown in color.
*It is granular in appearance.
*It contain renal corpuscles and convoluted tubules.
ii)Renal Medulla;
*Inner portion of kidney is called renal medulla.
*It is light brown in color.
*It contains vascular and tubular structures.
*it contains 8 to 18 medullary pyramids.
iv)Renal Pyramid;
*Renal pyramids are cone shaped structures.
*Base of each pyramid is in contact with cortex and apex of each pyramid is in contact with minor calyx as shown in the figure below.
Renal Sinus;
Renal sinus consists of following structures;
i)Renal Pelvis: Upper extended end of ureter is called renal pelvis.
ii)Major Calyces: Renal pelvis divides into two or three major calyces.
iii)Minor Calyces: Major Calyces divides into two or three minor calyces.
iv) Renal Papillia: The depression in the minor calyx due to renal pyramid is called renal papillia.
*Hilum; The depression portion of kidney through which blood vessels enter and exit the kidney is called hilum.
 |
| structures of kidney |
Important Relations of Right Kidney;
Anteriorly;
Following structures are present posterior to the left kidney.
i)Suprarenal Gland,
ii)Liver
iii)Second Part of Doudenum,
iv)Right Colic Flexure
Posteriorly;
Following structures are present posterior to the left kidney.
i)Little part of pluera,
ii)Psoas, quadratus lumborum and transverse abdominis muscle,
iii)subcostal, iliohypogastric, ilioinguinal nerves run behind right kidney.
iv)12th rib,
Important Relation of left Kidney:
Anteriorly:
Following structures are present anterior to the left kidney.
*Suprarenal Renal Gland,
*the Stomach,
*the spleen,
*the pancreas,
*left colic flexure,
*coils of jejenum,
Posteriorly:
Following structures are present posterior to the left kidney.
*the diaphragm,
*little part of pleura,
*11th and 12th ribs,
*Psoas, quaratus lumborum, and transverse abdominis muscles.
*Subcostal, iliohypogastric, ilioinguinal nerves run behind and laterally to left kidney.
Function of Kidney;
Kidney performs following functions:
1)Excretory functions of Kidney includes;
i)The filtration of nitrogenous waste from blood.
ii)Removal of nitrogenous waste outside the body in the form of urine.
2)Osmoregulatory Functions of Kidney Includes:
i) Formation of dilute urine during more availability of water.
ii)Formation of concentrated urine during less availability of water.
x