Each nephron consists of a small, cup-shaped structure called Bowman’s capsule. From the capsule a tiny tubule comes out and takes a tortuous course called the proximal convoluted tubule, then dips down to form a wide Henle’s loop, whose ascending limb forms a second tubular coil called the distal convoluted tubule which enters a large straight tube called the collecting tubule.
Image Source: yournursingtutor.com
ADVERTISEMENTS:
The collecting tubule receives the tubules of many nephrons. The collecting tubule carries the urine towards the pelvis.
In the cavity of Bowman’s capsule is a network of capillaries called the glomerulus. An afferent arteriole from a branch of renal artery forms the glomerulus.
The capillaries forming the glomerulus at the exit of Bowman’s capsule unite to form an efferent arteriole which goes towards the proximal convoluted tubule and forms another network of capillaries peritubular capillaries around the proximal convoluted tubule, the loop of Henle and the distal convoluted tubule.
These capillaries then form venules which join together to form the branch of the renal vein which removes the venous blood of the kidney.
ADVERTISEMENTS:
The afferent arterioles, glomeruli and efferent arterioles contain arterial blood. It should be noted that efferent arterioles have smaller diameters than afferent arterioles.
This increases the pressure in the glomerular capillaries, which is important for the process of urine formation.
The arterial blood changes to venous blood, while blood flows through the capillaries found around the proximal convoluted tubule, the loop of Henle and the distal convoluted tubule.
It is to be noted that formation of urine always takes place in the uriniferous tubules or nephrons where as the collecting tubules do not take any part in the urine formation but they simply convey the urine to the pelvis via pyramids for removal.