Plasma containing both wastes and nutrients passes into the nephrons of the kidneys where the nutrients are returned to the blood and the wastes left behind in a fluid called 'filtrate.' This filtrate is refined on its way to becoming 'urine.' In addition to removing waste from blood plasma the kidneys regulate the degree of hydration of the body.
This structure is outlined in black and begins near the upper left corner of the mind map. The cup-shaped Bowman's capsule is the first portion followed by the proximal convoluted tubule shown as a horizontal scalloped region.
Decending down the right side of the mind map is a straight region representing the decending limb of Henle. At the lower right corner of the map this bends back on itself to become the ascending limb of Henle. The walls of the ascending limb are thick to represent its impermeability to water.
The following region--also impermeable to water--bends to the left and is scalloped and horizontal; this is the early distal convoluted tubule. It is shown folding back on itself with its walls drawn as a thick but broken line that symbolizes its permeability to water is variable. This region is the late distal convoluted tubule.
The final region of the nephron is the collecting duct shown as a vertical extention of the late distal convoluted tubule. It's permeability to water is also variable.
The structure outlined in red represents the blood supply. Pressing into Bowman's capsule is the glomerulus. The region arching up and over Bowman's capsule is the efferent arteriole.
The next region that runs horizontally beneath the proximal convoluted tubule represents the peritubular capillaries. At the right the vessel is drawn straight and vertical to represent the decending limb of the vasa recta. At the bottom of the mind map it folds back upon itself and becomes the ascending limb of the vasa recta.
The next region that turns to the left to become horizontal represents, once more, the peritubular capillaires. Next there is a gap in this vascular system indicating we are leaving the kidneys. The separate U-shaped region represents the extrarenal vascular system
The new start of the vascular system represents a return to the kidneys as the afferent arteriole. As it passes upward it contacts the distal convoluted tubule forming the juxtaglomerular apparatus. This structure consists of two parts. On the vascular side is a region called the juxtaglomerular cells, JGC and on the nephron side is a region called the macula densa, MD.
At the center of the left margin of the mind map are two circles that represent the vasoconstrictor center, VC and the vasodilator center, VD.
Last Updated: 7/19/2005