Topic 11.3: Kidney and Osmoregulation

Essential Idea:  All animals excrete nitrogenous waste products and some animals also balance water and solute concentrations.
At SHS, Topic 11.3 is taught in the following class unit(s):

Statements & Objectives:

11.3.U1  Animals are either osmoregulators or osmoconformers.
  • Define osmoregulator and osmoconformer.
  • List three example osmoregulator animals and hree example osmoconformer animals.
11.3.U2  The Malphigian tubule system in insects and the kidney carry out osmoregulation and removal of nitrogenous wastes.
  • Define osmoregulation.
  • State the nitrogenous waste products found in insects and mammals.
  • Outline the structure and function of the Malpighian tubule system.​
11.3.U3  The composition of blood in the renal artery is different from that in the renal vein.
  • State the functions of the kidney.
  • Distinguish between osmoregulation and excretion.
  • List 4 substances that are found in higher concentration in the renal artery than in the renal vein.
  • Compare the relative glucose, oxygen and carbon dioxide concentrations between the renal artery and the renal vein.
  • State that plasma proteins are not filtered by the kidney so should be present in the same concentration in the renal artery and renal vein.
11.3.U4  The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration.
  • Outline the cause and effect of high blood pressure in the kidney glomerulus.
  • List solutes found in glomerular filtrate.
  • Define filtrate and ultrafiltration.
  • Explain why plasma proteins and blood cells are not part of glomerular filtrate.
  • On a glomerulus diagram, label the basement membrane, fenestrations, podocyte foot processes, podocytes.
  • Outline the role of fenestration, the basement membrane and podocytes in ultrafiltration.
  • Describe the relationship between the glomerulus and Bowman’s capsule.
11.3.U5  The proximal convoluted tubule selectively reabsorbs useful substances by active transport.
  • List substances in the glomerular filtrate that are reabsorbed in the proximal convoluted tubule.
  • Explain why cells lining the lumen of the proximal convoluted tubule have microvilli and many mitochondria.
  • Outline the mechanism of selective reabsorption of sodium ions, chloride ions, glucose and water.
11.3.U6  The loop Henle maintains hypertonic conditions in the medulla.
  • State the overall function of the loop of Henle.
  • Outline the role of interstitial fluid in osmoregulation.
  • Describe the structure and function of the descending limb of the loop of Henle.
  • Describe the structure and function of the ascending limb of the loop of Henle.
  • Describe why the loop of Henle is a countercurrent multiplier system.
11.3.U7  The length of the loop of Henle is positively correlated with the need for water conservation in animals.
  • Outline the relationship between habitat and length of the loop of Henle.
  • Outline the relationship between habitat and relative medullary thickness.
11.3.U8  ADH controls reabsorption of water in the collecting duct.
  • Outline the tonicity of filtrate entering the distal convoluted tubule from the loop of Henle.
  • Outline the of low blood solute concentration on  the volume of urine produced, solute concentration in the urine, permeability of the distal convoluted tubule and collecting duct to water and volume of water reabsorbed.
  • Outline the of high blood solute concentration on  the volume of urine produced, solute concentration in the urine, permeability of the distal convoluted tubule and collecting duct to water and volume of water reabsorbed.
  • Outline the source and function of ADH in osmoregulation.
1.3.U9  The type of nitrogenous waste in animals is correlates with evolutionary history and habitat.
  • Outline the production and effect of ammonia in animals.
  • State the nitrogenous waste products released by:  aquatic organisms, terrestrial organisms, marine mammals, amphibians, birds and insects.
  • Compare urea and uric acid.
11.3.A1  Consequences of dehydration and over-hydration.
  • Outline the causes and consequences of dehydration.
  • Outline the causes and consequences of overhydration.
11.3.A2  Treatment of kidney failure by hemodialysis or kidney transplant.
  • List two common causes of kidney failure.
  • Outline the process of hemodialysis.
  • Outline the process of kidney transplant.
  • Outline the treatment of kidney stones by ultrasound.​
11.3.A3  Blood cells, glucose, proteins and drugs are detected in urinary tests.
  • Define urinalysis.
  • Outline the use of a urine test strip in detection of diabetes, kidney damage and drug use.
  • Outline the microscopic examination of urine for detection of infection, kidney stones or kidney tumors.
11.3.S1  Drawing and labeling a diagram of the human kidney.
  • Draw a diagram of a human kidney.
  • Label the renal artery, renal vein, cortex, medulla, renal pelvis and ureter on a diagram of the human kidney.
11.3.S2  Annotations of a diagram of the nephron.
  • Define nephron.
  • Annotate a diagram of the nephron with the following structures and associated functions:  Bowman’s capsule, proximal convoluted tubule, Loop of Henle,. distal convoluted tubule, collecting duct, afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries, vasa recta and venules.
11.3.NOS  Curiosity about particular phenomena- investigations were carried out to determine how desert animals prevent water loss in their wastes.
  • State that many scientific discoveries have come from simple curiosity about particular phenomena.
I give many of my IB Biology resources away, for the benefit of students and teachers around the world.  If you've found the materials helpful, please consider making a contribution of any amount to this Earthwatch Expedition Fund. 

​Did I forget something?  Know of a mistake? Have a suggestion?  Let me know by emailing me here. Cheers!

Before using any of the files available on this site, please familiarize yourself with the Creative Commons Attribution License.  ​​It prohibits the use of any material on this site for commercial  purposes of any kind.  ​

"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." 
 John Muir,   1911