Deck 13: Fluid and Acid-Base Balance

Question 1

Blood plasma in birds is about ______ of the ECF.

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

Answer 1

40%

Question 2

In vertebrates

A) the ECF and ICF have the same composition.
B) the plasma and the interstitial fluid have similar composition.
C) the cellular proteins freely permeate into the ECF from ICF.
D) the concentration of sodium ions and potassium ions in ECF and ICF is the same.
E) all these.

Answer 2

the plasma and the interstitial fluid have similar composition.

Question 3

Which of the following statements is NOT true?

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 PO₄^3-.
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.

Answer 3

In most organisms Na⁺ is the primary ion in the ICF.

Question 4

The net transfer of water between the interstitial fluid and ICF across the plasma membrane

A) is mainly due to the difference in the osmotic force between the ICF and the interstitial fluid.
B) is controlled by the channel proteins in the plasma membrane.
C) is primarily due to the difference in the hydrostatic pressure between ICF and the interstitial fluid.
D) all these.
E) none of these.

Question 5

When sodium ions enter a cell

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 6

Insects prevent water loss and disturbance in the osmotic balance in cells by

A) having a water-proof cell wall around each cell.
B) having a cuticle that makes the body water-proof.
C) having an outer epidermis made of keratinized cells.
D) having equal concentration of molecules in ECF and ICF.

Question 7

Which of the following is NOT correctly paired?

A) organic osmolytes and compatible solutes
B) counteracting solute and TMAO
C) methylamine and proline
D) carbohydrate and myo-inositol
E) none of these.

Question 8

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

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 9

Important organic osmolytes in marine osmoconformers are

A) polyols and sugars.
B) glycine and taurine.
C) methylamine and methylsulfonium.
D) urea.
E) all of these.

Question 10

Which among the following byproducts of bacterial action on an organic osmolyte in fish is used as an indicator of fish spoilage?

A) urea
B) ammonia
C) trimethylamine (TMA)
D) dimethylsufoxide (DMS)
E) taurine

Question 11

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?

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 12

Stenohaline osmoconformers such as sea anemones and sea stars

A) can tolerate a wide range of osmotic changes in their marine environment.
B) have limited tolerance to changes in salinity of the surrounding sea water.
C) are adapted to live in marine and fresh water habitats.
D) use methylamines and amino acids in ECF to maintain osmotic balance.
E) regulate the osmolytes in ICF and ECF in order to survive extreme changes in salinity of sea water.

Question 13

Animals living in intertidal zones are

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 14

Marine sharks and rays

A) are ureosmotic conformers.
B) are hyper-ionic osmoconformers.
C) have ICF and ECF with equal or slightly higher osmotic pressure than the sea water.
D) two of these.
E) all of these.

Question 15

In sharks and rays TMAO

A) is present in a 2:1 ratio with urea.
B) counteracts the toxic effect of urea.
C) serves as a hyper-ionic regulator.
D) two of these.
E) all of these.

Question 16

Osmoregulators:

A) change the ECF osmotic pressure when osmotic pressure in the surrounding water changes.
B) have to regulate ICF organic osmolytes to counteract cell volume changes.
C) maintain a relatively steady ECF osmotic pressure even when the osmotic pressure changes in the external environment.
D) are hyperosmotic in marine environments.
E) are hypo-osmotic in freshwater environments..

Question 17

Muscle is about _________ water.

A) 25%
B) 45%
C) 60%
D) 75%
E) None of these.

Question 18

Fresh water vertebrates

A) are hyper-osmotic regulators.
B) produce large volumes of hypotonic urine.
C) maintain lower internal osmolarities in order to minimize water intake.
D) are adapted to take in ions of sodium, chlorine and calcium by means of gills, chloride cells and moist skin.
E) all these.

Question 19

In osmoregulators such as mammals

A) the osmotic balance between the ECF and the ICF is carefully monitored and controlled by the kidneys.
B) cells will lose water if the ECF becomes hypertonic.
C) some cells exhibit RVI (regulatory volume increase) as a way of compensating water loss when the ECF becomes hypertonic.
D) the ICF is influenced by changes in the ECF.
E) all of these.

Question 20

Camels are perfectly adapted to desert conditions because

A) they can tolerate up to 30% loss of body water without any severe consequences.
B) they can slow down their metabolism when dehydration causes hypertonicity of ECF.
C) they have the ability to maintain plasma volume at the same homeostatic range even when the interstitial fluid becomes hypertonic.
D) their body cells do not go into osmotic shock when they drink water rapidly after prolonged dehydration.
E) all of these.

Question 21

Vasopressin and thirst are inhibited when

A) ECF increases.
B) plasma volume increases.
C) arterial blood pressure is raised.
D) ECF and plasma volumes increase
E) all of these.

Question 22

Increase in ECF osmolarity

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 23

Mammalian herbivores

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 24

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

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

Question 25

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

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 26

Acidosis in humans

A) results when blood pH goes below 7.35.
B) reduces oxygen delivery to cells by hemoglobin.
C) depresses the central nervous system, and may lead to coma and death.
D) two of these.
E) all of these.

Question 27

When [H⁺] in the blood increases from the optimum

A) kidney (renal) tubules remove hydrogen ions by tubular secretion.
B) kidney tubules retain more potassium ions than what the body needs.
C) retained potassium ions adversely affect cardiac functions.
D) kidney tubules secrete H⁺ and absorb K⁺.
E) all of these.

Question 28

The major source of hydrogen ions in the body is

A) dietary intake of acids such citric acid and acetic acids.
B) phosphoric acids and sulfuric acids formed by protein metabolism.
C) fatty acid metabolites such as keto acids.
D) carbon dioxide produced by cellular respiration.
E) hydrochloric acid produced by gastric glands.

Question 29

Buffering of lactic acid produced during anaerobic glycolysis in the Painted Turtle (Chrysemys picta) during winter is by

A) the carbon dioxide-carbonic acid buffers.
B) the massive shell of the turtle.
C) the phosphate buffers.
D) the protein buffers.
E) all of these.

Question 30

Which of the following is NOT correctly paired?

A) distal tubule and intercalated cells
B) Type A intercalated cells and H⁺ secretion
C) Type A intercalated cells and HCO₃^- reabsorption
D) proximal tubule and H⁺ secretion
E) fish gills and H+ ATPase pumps

Question 31

Kidneys maintain acid-base balance in the body by

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 32

During acidosis, the renal tubules:

A) secrete more hydrogen ions into the filtrate.
B) filter out more bicarbonate ions from blood.
C) retain more hydrogen ions in blood.
D) reabsorb less bicarbonates from the filtrate.
E) two of these.

Question 33

During alkalosis, the renal tubules

A) secrete less hydrogen into the filtrate.
B) filter out more bicarbonate ions from blood into the filtrate.
C) reabsorb very little bicarbonate ions from the filtrate.
D) all of these.
E) none of these.

Question 34

Transcellular fluids consist of a number of small specialized fluid volumes that are
secreted by specific cells into a particular cavity to perform some specialized function.

Question 35

Mammalian cerebrospinal fluid decreases in volume when the body as a whole is
experiencing a negative water balance.

Question 36

Hyperosmotic regulation is found in all freshwater animals.

Question 37

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

Question 38

An animal with abnormally low sodium levels is suffering from hyponatremia

Question 39

Insects and arachnids get water from water vapor in humid air.

Question 40

A cold water fish will have a lower internal pH than a warm water fish.

Question 41

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

Question 42

Anytime the [HCO₃^-]/[CO₂] ratio falls below 10:1, an acidosis exists.

Question 43

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

Question 44

Match each sentence with the most appropriate choice:

-Trimethalamine (TMA)

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 45

Match each sentence with the most appropriate choice:

-DMSP (dimethyl sulfonopropionate)

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 46

Match each sentence with the most appropriate choice:

-Stenohaline

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 47

Match each sentence with the most appropriate choice:

-Euryhaline

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 48

Match each sentence with the most appropriate choice:

-Hyperosmotic regulators

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 49

Match each sentence with the most appropriate choice:

-Hyposomotic regulators

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 50

Match each sentence with the most appropriate choice:

-Uremic acidosis

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 51

Match each sentence with the most appropriate choice:

-Carbonic anhydrase

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 52

Match each sentence with the most appropriate choice:

-Chloride cells

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 53

Match each sentence with the most appropriate choice:

-Salt glands

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 54

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

Question 55

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?

Question 56

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

Question 57

Compare and contrast the use of compatible and counteracting organic osmolytes by osmoconformers and discuss the impact these substances have on ECF and ICF.