11.3  The Kidney and Osmoregulation

big ninja

Essential Idea:

All animals excrete nitrogenous waste products and some

animals also balance water and solute concentrations


  • All animals are either osmoregulators or osmoconformers
  • The Malpighian tubule system in insects and the kidney carry out osmoregulation and the removal of nitrogenous wastes
  • The composition of blood in the renal artery is different from that in the renal vein
  • The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration
  • The proximal convoluted tubule selectively reabsorbs useful substances by active transport
  • The loop of Henle maintains hypertonic conditions in the medulla
  • ADH controls reabsorption of water in the collecting duct
  • The length of the loop of Henle is positively correlated with the need for water conservation in animals
  • The type of nitrogenous waste in animals is correlated with evolutionary history and habitat


  • Consequences of dehydration and overhydration
  • Treatment of kidney failure by hemodialysis or kidney transplant
  • Blood cells, glucose, proteins and drugs are detected in urinary tests


  • Drawing and labelling a diagram of the human kidney
  • Annotation of diagrams of the nephron