• The following elements should be included in a drawing of the human kidney
  • The kidney should be?roughly oval in shape?with an?inward curve on the side?where it is?connected?to the?blood vessels and ureter
  • The?renal vein should be wider in diameter?than the?renal artery
  • All three kidney regions should be clearly shown
    • An?outer cortex?that takes up?roughly a fifth?of the kidney’s diameter
    • The?medulla within the cortex
      • The medulla has regions called ‘pyramids’?which should be visible
    • The?renal pelvis on the inward curve?of the kidney’s side, and?draining into the ureter
  • Lines should be drawn in?clear, dark pencil?with?no sketching
  • Label lines should?not cross each other?and should?cross as little of the drawing as possible
  • No shading or colour is required

A drawing of the kidney should be an accurate representation of the kidney’s shape, show the three main regions of the kidney, and show the kidney’s connections to blood vessels and the ureter

• Each kidney contains?thousands of tiny tubes, or?tubules, known as?nephrons
• Nephrons are the?functional unit of the kidney?and are responsible for the?formation of urine
• An annotated diagram of the nephron should include the following elements
• The?glomerulus
  • A?ball of capillaries?inside which blood flows at?high pressure?to bring about?ultrafiltration
• The?afferent?and?efferent arterioles?of the glomerulus
  • The afferent arteriole?brings blood into the glomerulus?from the renal artery and the efferent arteriole?carries blood away from the glomerulus?and into the peritubular capillaries
  • The?afferent arteriole is wider than the efferent arteriole?to generate high blood pressure in the glomerulus
  • Remember,?a?comes before?e?in the alphabet, and?afferent comes before?efferent in the blood flow through the kidney
• The?Bowman’s capsule
  • A cup-like structure into which the?blood of the glomerulus is filtered
• The?proximal convoluted tubule
  • The section of the kidney tubule in which?most reabsorption of sugars, water, and salts?occurs
  • It is lined with?tightly packed cells?that have?microvilli?and?many mitochondria?to aid the reabsorption process
  • Remember,?proximity means that something is?close by, so the?proximal convoluted tubule is?closest?to the glomerulus
• The?loop of Henle
  • A hairpin-like structure that?concentrates the filtrate?and?creates a concentration gradient?across the medulla in order to?maximise water reabsorption
  • The?descending?limb?descends?into the medulla, while the?ascending?limb?ascends?back up into the cortex
• The?distal convoluted tubule
  • The section of tubule that connects the loop of Henle with the collecting duct;?more water is reabsorbed here
  • The amount of water reabsorbed?depends on the amount of ADH?in the blood
  • Remember,?distant refers to something that is?far away, so the?distal convoluted tubule is?furthest away?from the glomerulus
• The?collecting duct
  • This tube?descends back into the medulla?and?drains into the renal pelvis
  • More water is reabsorbed?here
  • The amount of water reabsorbed?depends on the amount of ADH?in the blood
• The?vasa recta
  • The?capillary that flows alongside the loop of Henle?and into which water and salts are reabsorbed
• Peritubular capillaries and venules
  • Peritubular capillaries are a network of blood vessels in close proximity to the nephron into which substances are reabsorbed
  • Venules carry blood back towards the renal vein

Nephrons are the functional unit of the kidney