11.3 The Kidney and Osmoregulation

Understandings:

• 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

Applications:

• 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

Skills:

• Drawing and labelling a diagram of the human kidney

• Annotation of diagrams of the nephron