MT 13LAB- Urinary System

• alone perform the functions of the urinary system

  Kidneys
• What does the other organs do?

  Other organs in the urinary system only provide temporary storage for urine or serve as transportation channels to carry it from the kidneys to the outside of the body
• The kidney is about the size of a

  large bar of soap
• What are the three protective layers of the kidney

  fibrous capsule, perirenal fat capsule, renal fascia
• most superficial layer of dense fibrous connective tissue; anchor

  Renal fascia
• transparent layer, gives glistening appearance


  fibrous capsule
• fatty mass, cushions the kidneys

  Perirenal fat capsule
• 3 regions of the kidney

  renal cortex, renal medulla, renal pelvis
• deep to the cortex; has renal pyramids


  renal medulla
• funnel-shaped tube; continuous with the ureter


  renal pelvis
• outer region of the kidney


  renal cortex
• Extensions of the renal pelvis; Form "drains" that enclose the tips of the pyramids

  Calyces (calyx)
• Function of the calyces

  Collect urine which continuously drain from the tips of the pyramids into the renal pelvis
• Approximately ______ of the total blood supply of the body passes through the kidneys each minute

  25%
• supplies the kidney w/ oxygenated & nutrient-rich blood

  Renal Artery
• Renal Blood Supply

  aorta-> renal artery-> segmental artery-> interlobar artery-> arcuate artery-> cortical radiate artery-> afferent arteriole-> glomerular capillaries-> efferent arterioles-> peritubular capillaries-> cortical radiate vein-> arcuate vein-> interlobar vein-> renal vein-> inferior vena cava
• Structural and Functional units of each kidney

  Nephrons
• Nephrons does what


  Responsible for forming urine
• Two main structures of the nephron

  renal corpuscle and renal tubule
• The renal capsule consists of

  glomerulus and bowman's capsule
• Glomerulus is a


  knot of capillaries
• Bowman's Capsule is a


  hollow structure encloses the glomerulus
• Bowman's Capsule is also known as


  glomerular capsule
• Inner layer of the renal corpuscle is made up of

  podocytes
• have foot processes that intertwine with each other


  Podocytes
• What are the openings of the podocytes called?

  filtration slits
• What does the filtration slit do?

  allow the podocytes to create a porous membrane which is ideal for filtration
• Extends from the glomerulus, then it coils and twists forming a hairpin loop and then coil and twist again before entering the collecting duct

  Renal tubule
• Path of renal tubule

  Glomerulus → Proximal Convoluted Tubule (PCT) → Loop of Henle → Distal Convoluted Tubule → Collecting Duct
• run downwards to the medullary pyramids

  Collecting ducts
• What does the collecting duct do?

  deliver the FINAL urine product into the calyces and renal pelvis
• Two types of nephrons

  cortical and juxtamedullary
• situated close to the cortex-medulla junction


  juxtamedullary nephron
• make up majority of the nephrons; almost entirely in the cortex

  cortical nephrons
• Fed by the afferent arteriole; and feeds into the efferent arteriole

  Glomerulus
• Main function of glomerulus


  Specialized for the filtration of blood
• The afferent arteriole has a larger diameter than the efferent, resulting in a ________ in the glomerular capillaries

  much higher blood pressure
• Most of the filtrate (______) is eventually reabsorbed by the renaltubule cells


  ~99%
• Arises from the efferent arteriole that drains the glomerulus

  Peritubular Capillary Bed
• What is the peritubular capillary bed?

  Low-pressure, porous vessels adapted for absorption instead of filtration