Nephrons

• Nephrons - are the structural and functional units of the kidneys and are responsible for forming urine
• What are two main structures of each nephron?

  Renal Corpuscle, Renal Tubule
• Glomerulus - each renal corpuscle consists of this, which is a knot of capillaries
• Glomerular Capsule - a cup-shaped hallow structure that completely surrounds the glomerulus like a well-worn base-ball glove encloses a ball
• What is the other term for Glomerular Capsule?

  Bowman's Capsule
• Podocytes - are highly modified octopus-like cells that have long branching extensions
• Foot Processes - are long branching extensions that intertwine with one another and cling to the glomerulus
• Filtration Slits - are openings between foot processes that allow the podocytes to form a porous, or "leaky," membrane around the glomerulus ideal for filtration
• Renal Tubule - makes up the rest of the nephron, as it extends from the glomerular capsule to the collecting duct
• What are the regions of Renal Tubule?

  Proximal Convoluted Tubule, Nephron Loop, Distal Convoluted Tubule
• What is the other term for nephron loop?

  Loop of Henle
• Microvilli - covers the surfaces of the tubule cells in the PCT exposed to the filtrate, which increase their surface area
• Cortical Nephrons - most nephrons that are located entirely within the cortex
• Juxtamedullary Nephrons - nephrons that are situated close to the cortex-medulla junction and their nephron loops dip deep into the medulla
• Collecting Ducts - receives urine from many nephrons, run downward though the medullary pyramids, giving the pyramids a striped appearance
• Collecting Ducts deliver the final urine product into the calyces and renal pelvis
• What are the two capillary beds associated to each nephrons?

  Glomerulus, Peritubular Capillary Bed
• Afferent Arteriole - feeds the glomerulus with blood, which arises from a cortical radiate artery
• Efferent Arterioles - receives the blood as it leaves the glomerulus and branches out as peritubular capillaries
• Glomerulus - specialized for filtration, differs from any other capillary bed in the entire body
• What arterioles that has a larger diameter, which results in a much higher blood pressure?

  Afferent Arterioles
• Peritubular Capillary Bed - the second capillary bed that arises from the efferent arterioles that drains the glomerulus
• Peritubular Capillary Bed - are low-pressure, porous vessels adapted for absorption instead of filtration