Question 1

Why do marine osmoconformers use organic osmolytes in their ICF to attain osmotic balance instead of the more easily available inorganic osmolytes such as sodium, potassium and chloride ions?

Accepted Answer

A)  because organic osmolytes can be easily absorbed from the sea water 
B)  because organic osmolytes do not disrupt the function of macromolecules 
C)  because the cells can make organic osmolytes without using cellular energy 
D)  because the cells have to use energy to obtain inorganic osmolytes

Question 2

Which of the following statements is NOT true?

Accepted Answer

A)  In the ECF, Na+ is accompanied primarily by Cl- and to a lesser extent by HCO3-. 
B)  In the ICF K+ is accompanied by PO43-. 
C)  In most organisms Na+ is the primary ion in the ICF. 
D)  A fluid compartment found in all animals is produced by the digestive tract. 
E)  All plasma constituents except proteins are freely exchanged between plasma and interstitial fluid.

Question 3

Freshwater animals have more NaCl in the ECF and little or no amino acid osmolyes in
 the ICF.

Accepted Answer

A) True 
 B)False

Question 4

Match each sentence with the most appropriate choice:
-Uremic acidosis

Accepted Answer

A)  Severe renal failure 
B)  Excretion of salt by marine birds and reptiles 
C)  Mediates interconversion of CO2 and bicarbonates in RBC 
D)  Fish odor 
E)  Special cells in the gills of marine fish
F) Decaying sea weeds
G) Strict osmoconformers
H) Osmoregulators with tolerance for different salinities
I) Fresh water organisms
J) Marine bony fishes

Question 5

Increase in ECF osmolarity

Accepted Answer

A)  stimulates the osmoreceptors in the hypothalamus and causes the release of vasopressin (ADH). 
B)  may decrease systemic blood pressure. 
C)  may cause vasodilation in order to increase arterial blood pressure. 
D)  may cause the release of vasopressin and a decrease in systemic blood pressure. 
E)  may decrease systemic blood pressure and cause vasodilation.

Question 6

Excretory organs are the third line of defense against changes in [H+].

Accepted Answer

A) True 
 B)False

Question 7

When sodium ions enter a cell

Accepted Answer

A)  osmotic pressure of the cell increases. 
B)  water molecules accompany sodium ions. 
C)  the cell becomes swollen. 
D)  all these. 
E)  none of these.

Question 8

The most important factor regulating the mammalian ECF volume and blood pressure is

Accepted Answer

A)  vasopressin. 
B)  thirst. 
C)  increase of Na+ ions in ECF. 
D)  renin-angiotensin-aldosterone system. 
E)  decrease of K+ ions in ECF.

Question 9

Mammalian herbivores

Accepted Answer

A)  have more K+ ions than Na+ ions in their ECF. 
B)  swap Na+ for K+ in the distal tubule secretion. 
C)  drink more water than carnivores. 
D)  have more K+ ions than Na+ ions in their ECF and swap Na+ for K+ in the distal tubule secretion. 
E)  swap Na+ for K+ in the distal tubule secretion and drink more water than carnivores.

Question 10

Compare and contrast sodium handling by chloride cells with sodium handling in
 the mammalian kidney.

Accepted Answer

The answer of Compare and contrast sodium handling by chloride...

Question 11

How do stenohaline organisms maintain osmotic balance between their body fluid and the sea water surrounding them? Why do stenohaline organisms die when placed in fresh water?

Accepted Answer

The answer of How do stenohaline organisms maintain osmotic balance...

Question 12

pH of arterial blood is slightly higher than that of venous blood because

Accepted Answer

A)  arterial blood has more hydrogen ions. 
B)  arterial blood has less acidic metabolites such as carbon dioxide and lactic acid. 
C)  venous blood has less carbon dioxide. 
D)  arterial blood always has more oxygen. 
E)  of the H+ ions generated during the formation of HCO3-.

Question 13

Citing examples, describe the differences between hypo-ionic osmoconformers and hypo-osmotic osmoregulators. Your answer should specify how each group attains osmotic balance.

Accepted Answer

The answer of Citing examples, describe the differences between hypo-ionic...

Question 14

Match each sentence with the most appropriate choice:
-Trimethalamine (TMA)

Accepted Answer

A)  Severe renal failure 
B)  Excretion of salt by marine birds and reptiles 
C)  Mediates interconversion of CO2 and bicarbonates in RBC 
D)  Fish odor 
E)  Special cells in the gills of marine fish
F) Decaying sea weeds
G) Strict osmoconformers
H) Osmoregulators with tolerance for different salinities
I) Fresh water organisms
J) Marine bony fishes

Question 15

Animals living in intertidal zones are

Accepted Answer

A)  strict osmoconformers. 
B)  hypo-ionic osmoconformers. 
C)  euryhaline. 
D)  stenohaline. 
E)  not capable of changing the composition of ECF when the osmotic pressure of sea water changes.

Question 16

To overcome long-term osmotic challenges caused by osmotic changes in the external environment, osmoconformers

Accepted Answer

A)  raise their cellular content of sodium, potassium and chloride ions. 
B)  lower the level of sodium, potassium and chloride ions in the ICF. 
C)  raise the osmotic pressure of ICF by raising the level of organic osmolytes. 
D)  raise intracellular ion content and ICF osmotic pressure. 
E)  lower ICF ion content and osmotic pressure.

Question 17

Kidneys maintain acid-base balance in the body by

Accepted Answer

A)  removing hydrogen ions from all the sources in the body. 
B)  excreting bicarbonate ions rapidly when acidity of body fluid decreases. 
C)  secreting ammonia into the urine. 
D)  removing hydrogen ions and secreting ammonia into the urine. 
E)  removing hydrogen ions, secreting ammonia into the urine, and excreting bicarbonate ions when body fluid acidity decreases.

Question 18

Match each sentence with the most appropriate choice:
-Salt glands

Accepted Answer

A)  Severe renal failure 
B)  Excretion of salt by marine birds and reptiles 
C)  Mediates interconversion of CO2 and bicarbonates in RBC 
D)  Fish odor 
E)  Special cells in the gills of marine fish
F) Decaying sea weeds
G) Strict osmoconformers
H) Osmoregulators with tolerance for different salinities
I) Fresh water organisms
J) Marine bony fishes

Question 19

Blood plasma in birds is about ______ of the ECF.

Accepted Answer

A)  40% 
B)  15% 
C)  20% 
D)  70% 
E)  10%

Question 20

Insects have a feedforward activity for regulating pH in anticipation of increased activity.

Accepted Answer

A) True 
 B)False

Exam 13: Fluid and Acid-Base Balance

Why do marine osmoconformers use organic osmolytes in their ICF to attain osmotic balance instead of the more easily available inorganic osmolytes such as sodium, potassium and chloride ions?

Which of the following statements is NOT true?

Freshwater animals have more NaCl in the ECF and little or no amino acid osmolyes in the ICF.

Match each sentence with the most appropriate choice: -Uremic acidosis

Increase in ECF osmolarity

Excretory organs are the third line of defense against changes in [H⁺].

When sodium ions enter a cell

The most important factor regulating the mammalian ECF volume and blood pressure is

Mammalian herbivores

Compare and contrast sodium handling by chloride cells with sodium handling in the mammalian kidney.

How do stenohaline organisms maintain osmotic balance between their body fluid and the sea water surrounding them? Why do stenohaline organisms die when placed in fresh water?

pH of arterial blood is slightly higher than that of venous blood because

Citing examples, describe the differences between hypo-ionic osmoconformers and hypo-osmotic osmoregulators. Your answer should specify how each group attains osmotic balance.

Match each sentence with the most appropriate choice: -Trimethalamine (TMA)

Animals living in intertidal zones are

To overcome long-term osmotic challenges caused by osmotic changes in the external environment, osmoconformers

Kidneys maintain acid-base balance in the body by

Match each sentence with the most appropriate choice: -Salt glands

Blood plasma in birds is about ______ of the ECF.

Insects have a feedforward activity for regulating pH in anticipation of increased activity.