When a dehydrated human patient needs to be given fluids intravenously, he or she is given:
- water, which is hypotonic with respect to body fluids
 - saline at a concentration that is isotonic with respect to body fluids
 - glucose because it is a non-electrolyte
 - blood
 
The sodium ion is at the highest concentration in:
- intracellular fluid
 - extracellular fluid
 - blood plasma
 - none of the above
 
Cells in a hypertonic solution tend to:
- shrink due to water loss
 - swell due to water gain
 - stay the same size due to water moving into and out of the cell at the same rate
 - none of the above
 
The macula densa is/are:
- present in the renal medulla.
 - dense tissue present in the outer layer of the kidney.
 - cells present in the DCT and collecting tubules.
 - present in blood capillaries.
 
The osmolarity of body fluids is maintained at ________.
- 100 mOsm
 - 300 mOsm
 - 1000 mOsm
 - it is not constantly maintained
 
The gland located at the top of the kidney is the ________ gland.
- adrenal
 - pituitary
 - thyroid
 - thymus
 
Active transport of K+ in Malpighian tubules ensures that:
- water follows K+ to make urine
 - osmotic balance is maintained between waste matter and bodily fluids
 - both a and b
 - neither a nor b
 
Contractile vacuoles in microorganisms:
- exclusively perform an excretory function
 - can perform many functions, one of which is excretion of metabolic wastes
 - originate from the cell membrane
 - both b and c
 
Flame cells are primitive excretory organs found in ________.
- arthropods
 - annelids
 - mammals
 - flatworms
 
BUN is ________.
- blood urea nitrogen
 - blood uric acid nitrogen
 - an indicator of blood volume
 - an indicator of blood pressure
 
Human beings accumulate ________ before excreting nitrogenous waste.
- nitrogen
 - ammonia
 - urea
 - uric acid
 
Renin is made by ________.
- granular cells of the juxtaglomerular apparatus
 - the kidneys
 - the nephrons
 - All of the above.
 
Patients with Addison's disease ________.
- retain water
 - retain salts
 - lose salts and water
 - have too much aldosterone
 
Which hormone elicits the “fight or flight” response?
- epinephrine
 - mineralcorticoids
 - anti-diuretic hormone
 - thyroxine