Structure of the nepron

the structure of the nephron, it’s designed to filter blood and form urine, each kidney’s packed with around a million of these tiny units. it starts with the Bowman’s capsule, a cup-shaped structure that surrounds a bunch of capillaries called the glomerulus—together they form the renal corpuscle. blood enters through the afferent arteriole, gets filtered in glomerulus, and exits via the efferent arteriole. that pressure inside glomerulus forces water, salts, glucose, urea into the capsule, but big stuff like blood cells, proteins stay behind.

next comes the proximal convoluted tubule (PCT)—it reabsorbs most useful stuff like glucose, amino acids, water, ions back into blood. after PCT, fluid enters the Loop of Henle, a U-shaped tube with descending and ascending limbs. the descending limb lets water out, but not salt; the ascending limb does opposite—pumps out salt, keeps water in, helps set up the medullary concentration gradient.

then fluid enters the distal convoluted tubule (DCT), where more ions are adjusted—under control of hormones like aldosterone. finally, the collecting duct gathers urine from multiple nephrons, concentrates it by reabsorbing more water (under ADH’s control), and sends it down to the renal pelvis.

surrounding all this’s a network of peritubular capillaries and vasa recta, which help exchange materials between tubules and blood. whole nephron structure’s tightly regulated, so body can control water balance, pH, salt levels, and remove wastes efficiently.