Deck 49: Excretory Systems and Salt and Water Balance

Question 1

The main reason sodium and potassium ions CANNOT easily diffuse through plasma membranes is

A) these are large atoms and size prevents their diffusion through membranes.
B) they have a high solubility in lipids.
C) they have a low solubility in lipids.
D) they have a high solubility in water.
E) they have both a high solubility in water and a low solubility in lipids.

Answer 1

they have both a high solubility in water and a low solubility in lipids.

Question 2

An increase in the extracellular concentration of salts will cause body cells to ____ water and __.

A) lose, shrink
B) lose, swell
C) gain, shrink
D) gain, swell
E) metabolize, heat up

Answer 2

lose, shrink

Question 3

You have a patient who complains of pain in his joints. You ask whether he drinks much water during the day and find out he does not. You therefore suspect conversion of his usual nitrogenous waste ___________ into __________, followed by deposition into his joints.

A) ammonia, urea
B) urea, ammonia
C) uric acid, urea
D) urea, uric acid
E) uric acid, ammonia

Answer 3

urea, uric acid

Question 4

If you contrast the salt and water balance adaptations of freshwater and saltwater fishes, you find that

A) freshwater fishes do not drink water.
B) saltwater fishes do drink water.
C) freshwater fishes actively transport salts into their bodies at the gills.
D) saltwater fishes actively transport salts out of their bodies at the gills.
E) All of the choices for this question are correct.

Question 5

Water that organisms gain in the synthesis of ATP is termed ____ water.

A) metabolic
B) biochemical
C) recovered
D) condensation
E) None of the choices for this question are correct.

Question 6

You would expect water derived from the synthesis of ATP to be especially important for

A) small desert dwelling animals.
B) rain forest amphibians.
C) arctic mammals.
D) sea birds.
E) marine mammals.

Question 7

An animal that does NOT maintain a relatively constant internal water concentration as the osmolarity of its environment varies is termed an

A) osmoconformer.
B) osmoregulator.
C) isoconformer.
D) isoregulator.
E) hydroconformer.

Question 8

The primary disadvantage of an osmoregulator strategy is

A) pumping ions into or out of the body is energetically expensive.
B) pumping ions into or out of the body is not a significant energetic expense usually.
C) keeping relatively constant internal conditions deprives the central nervous system of critical information about the environment.
D) pumping water into or out of the body is energetically expensive.
E) physiological systems do not typically perform well under relatively constant conditions.

Question 9

An osmoconformer strategy is common to

A) birds.
B) fishes.
C) insects.
D) marine invertebrates.
E) mammals.

Question 10

Sharks are osmoconformers, but have a rectal gland that is similar in function to the salt gland of sea birds and sea turtles. This is an adaptation to which of the following problems?

A) loss of ions
B) gain of ions
C) loss of water
D) gain of water

Question 11

Freshwater flatworms have a _______ system that is primarily important in osmoregulation, so you would expect the urine in these tubules to have an osmolarity ____ the osmolarity of the body fluids.

A) protonephridial, lower than
B) protonephridial, higher than
C) metanephridial, lower than
D) metanephridial, higher than
E) protonephridial, similar to

Question 12

Mammals such as the vampire bat have the ability to generate a urine with a concentration of approximately 3,600 millisomoles (mOsm). If the concentration of their blood is approximately 300 mOsm, their water loss is ______ by producing a concentrated urine.

A) reduced by approximately 11/12
B) reduced by approximately ½
C) actually increased by approximately ½
D) reduced by approximately 5/6
E) not reduced

Question 13

Which of the following correctly describes the path of urine from formation to excretion in the mammalian kidney?

A) collecting duct ? renal pelvis ? ureter ? urinary bladder ? urethra
B) renal pelvis ? ureter ? urinary bladder ? urethra ? collecting duct
C) ureter ? collecting duct ? renal pelvis ? urinary bladder ? urethra
D) collecting duct ? ureter ? urinary bladder ? renal pelvis ? urethra
E) urethra ? collecting duct ? renal pelvis ? ureter ? urinary bladder

Question 14

Which of the following correctly describes the path of fluid as it is filtered from the blood and flows through the nephron?

A) Bowman's capsule ? proximal convoluted tubule ? loop of Henle ? distal convoluted tubule ? collecting duct
B) collecting duct ? Bowman's capsule ? proximal convoluted tubule ? loop of Henle ? distal convoluted tubule
C) Bowman's capsule ? loop of Henle ? proximal convoluted tubule ? distal convoluted tubule ? collecting duct
D) Bowman's capsule? distal convoluted tubule ? loop of Henle ? proximal convoluted tubule ? collecting duct
E) collecting duct ? distal convoluted tubule ? loop of Henle ? proximal convoluted tubule ? Bowman's capsule

Question 15

Which substances are reabsorbed in the proximal convoluted tubule?

A) K⁺ ions
B) Na⁺ ions
C) HCO₃^- ions
D) glucose
E) All of the choices for this question are correct.

Question 16

All of the following are functions of the mammalian kidney EXCEPT

A) water retention.
B) filtration of blood.
C) excretion of nitrogenous waste.
D) regulation of salt balance in the blood.
E) production of urea.

Question 17

The digestion and utilization of _______ creates the greatest need for nitrogenous waste secretion by the kidneys.

A) protein
B) starch
C) fat
D) oil
E) simple sugars

Question 18

Diabetes mellitus translates roughly as "copious urination" + "honey." This disease results from disorders of glucose uptake by systemic cells and can cause, among other symptoms, high levels of glucose in the blood and glucose appearing in the urine (this is what diastix measure). Which of the following is a reasonable explanation of this observation?

A) The reabsorption capacity of the kidney for glucose is exceeded.
B) A lack of sodium in the filtrate blocks the function of the Na⁺/glucose symport protein.
C) High levels of glucose interfere with ADH function.
D) The high levels of glucose induce a "dehydrated" state that promotes production of a large amount of dilute urine.
E) None of the choices given are a logical explanation for this observation.

Question 19

Sodium and potassium ions can easily diffuse through the lipid bilayer of plasma membranes.

Question 20

Transport of salts against their concentration gradients is energetically expensive.

Question 21

Animals that do not control internal water concentration also typically do not control the concentrations of ions like sodium and potassium.

Question 22

An animal that exhibits broad tolerance for changes in the salinity of its environment is said to be "euryhaline."

Question 23

The materials in urine are ONLY those that are filtered from the blood or hemolymph and not reabsorbed by the body following filtration.

Question 24

Malpighian tubules of insects secrete rather than filter to eliminate waste products.