Page 728 - Atlas of Histology with Functional Correlations

KIDNEY

System consists of two kidneys, two ureters, a bladder, and a urethra
Hilum contains renal artery, renal vein, and renal pelvis surrounded by renal

sinus
Darker outer region of kidney is cortex; lighter inner region is medulla
Medulla contains numerous pyramids, which face the cortex at
corticomedullary junction

Round apex of each pyramid extends toward renal pelvis as renal papilla
Cortex that extends on each side of renal pyramid constitutes the renal
columns
Each papilla is surrounded by a minor calyx that joins to form a major calyx

Major calyces join to form funnel-shaped renal pelvis that narrows into
muscular ureter
Urine is formed as a result of blood filtration and absorption from and
excretion into the filtrate

Almost all filtrate is reabsorbed into the systemic circulation and about 1% is
voided as urine
Produces renin that regulates filtration pressure and erythropoietin for
erythrocyte production

Uriniferous Tubules

Functional unit of kidney is uriniferous tubule
Consist of nephron and collecting duct

Nephrons of Kidney

Two types of nephrons: cortical nephrons in cortex and juxtamedullary
nephrons in medulla

Nephron is subdivided into renal corpuscle and renal tubules

Renal Corpuscle

Blood is filtered in the glomerular capillaries of the corpuscle to form
ultrafiltrate

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