Extract from notes:
"FUNCTION OF THE NEPHRON
ULTRAFILTRATION – process by which blood plasma is filtered through the walls of the Bowman’s capsule under pressure; occurs in the glomerulus and the cells lining the Bowman’s capsule
- Urea, along with salt, water and glucose, etc., is extracted from the blood in the kidney
- Glomerulus is supplied w/ blood by a wide AFFERENT arteriole (from the renal artery)
- Blood leaves through the narrower EFFERENT arteriole; large pressure in the capillaries forces blood out of the glomerulus capillary walls fluid passes through the basement membrane (network of collagen fibres & proteins; the second filter)
- Plasma contents can pass through the basement membrane, but erythrocytes and large plasma proteins are RETAINED in the capillary"