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Glomerulus (kidney)
The glomerulus (plural glomeruli) is a network of small blood vessels (capillaries) known as a ''tuft'', located at the beginning of a nephron in the kidney. Each of the two kidneys contains about one million nephrons. The tuft is structurally supported by the mesangium (the space between the blood vessels), composed of intraglomerular mesangial cells. The blood is filtered across the capillary walls of this tuft through the glomerular filtration barrier, which yields its filtrate of water and soluble substances to a cup-like sac known as Bowman's capsule. The filtrate then enters the renal tubule of the nephron. The glomerulus receives its blood supply from an afferent arteriole of the renal arterial circulation. Unlike most capillary beds, the glomerular capillaries exit into efferent arterioles rather than venules. The resistance of the efferent arterioles causes sufficient hydrostatic pressure within the glomerulus to provide the force for ultrafiltration. The glome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowman's Capsule
Bowman's capsule (or the Bowman capsule, capsula glomeruli, or glomerular capsule) is a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine. A glomerulus is enclosed in the sac. Fluids from blood in the glomerulus are collected in the Bowman's capsule. Structure Outside the capsule, there are two "poles": * The vascular pole is the side with the afferent arteriole and efferent arteriole. * The urinary pole is the side with the proximal convoluted tubule. Inside the capsule, the layers are as follows, from outside to inside: *''Parietal layer''—A single layer of simple squamous epithelium. Does not function in filtration. *''Bowman's space (or "urinary space", or "capsular space")''—Between the visceral and parietal layers, into which the filtrate enters after passing through the filtration slits. *''Visceral layer''—Lies just above the thickened glomerular b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
