Deck 23: External Respiration: the Physiology of Breathing

Question 1

One of the exceptional adaptations of tuna is

A) their exceptionally large gill mass to body mass ratio.
B) their exceptionally large gill surface area.
C) their exceptionally high pressure opercular suction pump.
D) their exceptionally fast opercular pumping rate.

Answer 1

B

Question 2

During high-speed swimming, many fish rely on a method of ventilation called

A) ram ventilation.
B) opercular pumping ventilation.
C) the opercular suction pump.
D) buccal pressure pumping ventilation.

Answer 2

A

Question 3

Which statement is the most accurate definition of external respiration?

A) Bulk flow (convection) of air or water to and from the gas-exchange membrane.
B) The process by which O₂ is transported to the gas-exchange membrane from the environmental medium and by which CO₂ is transported away from the membrane into the environmental medium.
C) The process by which CO₂ is transported to the gas-exchange membrane from the environmental medium and O₂ is transported away from the membrane into the environmental medium.
D) Diffusion of O₂ and CO₂ across the gas exchange membrane.

Answer 3

B

Question 4

Which animal is an example of a bimodal breather?

A) Dog
B) Frog
C) Lizard
D) Crocodile

Question 5

The rate of O₂ uptake by the breathing organ depends on the

A) volume flow of air or water per unit of time.
B) amount of O₂ removed from each unit of volume.
C) amount of CO₂ needing to be removed.
D) volume flow of respiratory medium per unit time and the amount of O₂ removed from each unit volume.

Question 6

Which morphology sets up the least efficient gas exchange?

A) Cocurrent gas exchange
B) Convex current gas exchange
C) Cross-current gas exchange
D) Countercurrent gas exchange

Question 7

Refer to the figure shown.
The diagram is referring to what physiological process?

A) Cocurrent gas exchange
B) Countercurrent gas exchange
C) Nondirectional ventilation and gas exchange
D) Cross-current gas exchange

Question 8

Refer to the figure shown.
At I in the diagram, O₂ partial pressures are _______ the corresponding medium values and _______ from left to right.

A) lower than; increase
B) lower than; decrease
C) higher than; increase
D) higher than; decrease

Question 9

Refer to the figure shown.
O₂ partial pressures at II in the diagram are always _______ those at III.

A) equal to
B) lower than
C) higher than
D) half of

Question 10

CO₂ is more easily transferred into water across respiratory membranes compared to O₂ because CO₂

A) is more soluble in water.
B) moves faster.
C) is a smaller molecule.
D) has a higher cohesive force.

Question 11

Refer to the figure shown.
Which area indicates free HIF-1?

A) I
B) II
C) III
D) IV

Question 12

Refer to the figure shown.
When O₂ in a cell drops

A) more of compound I is created via enzymatic reactions.
B) more of compound II is created via enzymatic reactions.
C) more of compound I is produced by inhibiting its breakdown.
D) product III formation is catalyzed directly by low O₂.

Question 13

HIF-1 and HIF-2 can help increase the O₂-carrying ability of the blood by

A) increasing the secretion of erythropoietin.
B) increasing ventilation rate.
C) decreasing the diffusion distance at the lungs.
D) increasing circulation rate.

Question 14

Walking around at an altitude of 5000 m, you could expect which of the following responses at the whole-body level?

A) increase in the secretion of erythropoietin in certain cells
B) increase in heart rate
C) decreasing the diffusion distance at the lungs
D) increase in formation of HIF-1

Question 15

Which animal is likely to have the highest O₂ and CO₂ exchange percentage via the skin?

A) Goldfish
B) Bullfrog larva
C) Lungless salamander
D) Adult bullfrog

Question 16

In all vertebrates, the central pattern generators for breathing are located in the

A) cerebellum.
B) lungs.
C) cortex.
D) medulla.

Question 17

Refer to the figure shown.
Of the animals in the figure, which one represents a primarily aquatic animal using lungs as the primary source for O₂ uptake?

A) I
B) II
C) III
D) IV

Question 18

How does a typical teleost fish, such as a goldfish, maintain ventilation of its gills when stationary in the water column?

A) With a buccal pressure pump
B) With an opercular suction pump
C) Via ram ventilation
D) With both a buccal pressure pump and an opercular suction pump

Question 19

Choose the best statement regarding buccal-opercular pumping.

A) The opercular pump develops positive pressure while the buccal pump is being refilled, and the buccal pump sucks while the opercular pump is being emptied.
B) The opercular pump sucks while the buccal pump is being refilled, and the buccal pump sucks while the opercular pump is being emptied.
C) The opercular pump sucks while the buccal pump is being refilled, and the buccal pump develops positive pressure while the opercular pump is being emptied.
D) The opercular pump develops positive pressure while the buccal pump is being refilled, and the buccal pump develops positive pressure while the opercular pump is being emptied.

Question 20

Fish make use of _______ exchange in their gills.

A) cross-current
B) concurrent
C) cocurrent
D) countercurrent

Question 21

Which statement about air-breathing fish is false?

A) In most air-breathing fish, some part or branch of the alimentary canal has become specialized as an air-breathing organ.
B) Most air-breathing fish have lost gill function.
C) Air-breathing fish typically void most of their CO₂ into the water.
D) Many air-breathing fish are able to shunt blood.

Question 22

An adult bullfrog excretes CO₂ primarily through its

A) skin.
B) gills.
C) lungs.
D) cloaca.

Question 23

During metamorphosis, a frog utilizes which gas-exchange organs?

A) Gills only
B) Lungs only
C) Gills and lungs
D) Gills, skin, and lungs

Question 24

During the _______ developmental stage, the bullfrog splits oxygen uptake (roughly 50:50) between the gills and the skin.

A) aquatic tadpole
B) air-breathing tadpole
C) postmetamorphic froglet
D) adult

Question 25

Refer to the figure shown.
Which pair of lines best represents the lungs of the bullfrog?

A) I and IV
B) II and IV
C) I and VI
D) III and V

Question 26

Refer to the figure shown.
Which line best represents the excretion of CO₂ via the skin?

A) I
B) II
C) III
D) IV

Question 27

Which is primarily responsible for moving air into the lungs of a lizard?

A) The buccal pump
B) The buccopharyngeal pump
C) The intercostal muscles
D) The diaphragm

Question 28

Which statement is a recently discovered similarity between alligator respiration and bird respiration?

A) Cross-current gas exchange takes place.
B) Air sacs are present.
C) Ventilation is tidal.
D) Ventilation is unidirectional.

Question 29

Crocodilians and turtles have _______ lungs, which have a significantly _______ surface area compared to _______ lungs.

A) unicameral; smaller; multicameral
B) multicameral; smaller; unicameral
C) multicameral; greater; unicameral
D) unicameral; greater; multicameral

Question 30

Which animal group(s) ventilate(s) with the use of negative pressure?

A) Reptiles
B) Mammals
C) Amphibians
D) Both reptiles and mammals

Question 31

In which structure does diffusion of oxygen to capillaries not play a major role?

A) Terminal bronchioles
B) Respiratory bronchioles
C) Alveolar ducts
D) Alveolar sacs

Question 32

Pulmonary surfactant

A) keeps the alveoli from collapsing by reducing the surface tension.
B) inflates the alveoli by increasing the surface tension.
C) keeps the alveoli from collapsing by increasing the surface tension.
D) increases the rate of gas exchange across the alveoli by the secretion of phospholipids.

Question 33

During heavy exercise, we observe a significant increase in the use of the _______ for exhalation compared to resting conditions.

A) diaphragm
B) internal intercostals
C) external intercostals
D) sternocleidomastoid

Question 34

The volume of air in the lungs following a complete exhalation of the expiratory reserve volume is

A) one-half the inspiratory reserve volume.
B) called the tidal volume.
C) very close to 0 mL.
D) called the residual volume.

Question 35

If the inspiratory reserve volume is 3000 mL, the tidal volume is 500 mL, the expiratory reserve volume is 1000 mL, and the residual volume is 1000 mL, what is the vital capacity?

A) 3500 mL
B) 4500 mL
C) 5000 mL
D) 5500 mL

Question 36

In the mammalian alveoli, the partial pressure of O₂ is _______ that of atmospheric air and the CO₂ partial pressure is _______ that of atmospheric air.

A) higher than; lower than
B) lower than; higher than
C) lower than; lower than
D) the same as; higher than

Question 37

Which animal group(s) has(have) a true diaphragm?

A) Reptiles and mammals
B) Birds and mammals
C) Mammals
D) Birds

Question 38

In mammals, ventilation is modulated by the chemosensation of

A) CO₂.
B) CO₂ and H⁺.
C) CO₂ and O₂.
D) CO₂, H⁺, and O₂.

Question 39

Hypoxia factors can respond to hypoxia (along with other possible cofactors or coactivators) with all of the following responses except

A) increased erythropoiesis.
B) increased synthesis of glucose transporters.
C) increased synthesis of enzymes of aerobic metabolism.
D) the promotion of angiogenesis.

Question 40

A rise in arterial blood CO₂ partial pressure by 5 mm Hg would increase ventilation frequency in humans. This mechanism would likely trigger increased ventilation in

A) all vertebrates.
B) just terrestrial vertebrates.
C) just aquatic vertebrates.
D) all animals.

Question 41

Which circumstance would increase ventilation frequency in humans?

A) A reduction in arterial blood CO₂ partial pressure by 15 mm Hg
B) A rise in venous blood CO₂ partial pressure by 15 mm Hg
C) A reduction in arterial blood O₂ partial pressure by 15 mm Hg
D) A rise in venous blood O₂ partial pressure by 15 mm Hg

Question 42

Suppose you are comparing blood samples and samples of alveolar gas from two native Peruvians resting in their dwellings-one at sea level and one at 4500 m altitude. The O₂ partial pressure would likely be the most similar in

A) their alveolar gas.
B) their arterial blood.
C) their venous blood.
D) the air in their tracheas.

Question 43

When lowlanders first ascend to high altitude, which of the following occurs?

A) Hypoventilation
B) Bradycardia
C) Lowering of V̇o_2max
D) Hyperventilation

Question 44

The rate at which new air is brought into the alveoli and other respiratory pathways is called the

A) alveolar minute volume.
B) respiratory minute volume.
C) tidal volume.
D) ventilation rate.

Question 45

As mammals get smaller, lung volume _______ and breathing frequency _______.

A) increases exponentially; increases exponentially
B) decreases exponentially; increases exponentially
C) decreases proportionally; increases exponentially
D) increases proportionally; decreases proportionally

Question 46

Bird respiration is characterized by _______ air flow and _______ gas exchange.

A) nondirectional; countercurrent
B) unidirectional; cross-current
C) nondirectional; cross-current
D) unidirectional; countercurrent

Question 47

Refer to the figure shown.
Which of the arrows in the figure is showing air movement during inhalation incorrectly?

A) I
B) II
C) III
D) IV

Question 48

Refer to the figure shown.
The figure represents the respiratory system of which group of animals?

A) Amphibians
B) Reptiles
C) Birds
D) Fish

Question 49

Which structure(s) is(are) primarily responsible for gas exchange in the bird respiratory system?

A) Mesobronchus
B) Secondary bronchi
C) Parabronchi
D) Air sacs

Question 50

Branchial papulae are essentially gill processes in which major animal group?

A) Annelids
B) Horseshoe crabs
C) Aquatic snails
D) Sea stars

Question 51

The evolution of sheetlike gills occurred in which major animal group?

A) Annelids
B) Horseshoe crabs
C) Echinoderms
D) Molluscs

Question 52

The evolution of the mantle cavity into a lung occurred in which major animal group?

A) Annelids
B) Horseshoe crabs
C) Sea stars
D) Snails

Question 53

An aquatic decapod crustacean moves water through the branchial chamber and ventilates the gills with its

A) opercular pump.
B) buccal pump.
C) mouth.
D) scaphognathite.

Question 54

Which statement about land crab respiration is true?

A) Most land crabs have evolved lungs.
B) They allow their gills to go dry and ventilate them with air.
C) Their gills are ventilated with water.
D) O₂ is taken up chiefly by their branchial-chamber epithelium.

Question 55

The entrance to the gas exchange system of insects is via

A) spiracles.
B) the mouth.
C) the scaphognathite.
D) the branchial chamber.

Question 56

Although tracheoles run between cells, they also very commonly penetrate _______ cells.

A) flight muscle
B) nervous system
C) circulatory system
D) heart muscle

Question 57

A key mechanism of gas transport through the tracheal system is

A) muscular contraction.
B) the scaphognathite.
C) diffusion.
D) spiracle size.

Question 58

Comparing insect and vertebrate breathing,

A) vertebrates rely on conspicuous ventilation and insects rely on diffusion.
B) both use conspicuous ventilation and diffusion.
C) insects rely on conspicuous ventilation and insects rely on diffusion.
D) both rely on diffusion and only vertebrates rely on conspicuous ventilation.

Question 59

What is the main vulnerability of the insect respiratory system?

A) The release of accumulated CO₂ is slow.
B) It is susceptible to evaporative water loss.
C) It must be continually ventilated.
D) O₂ uptake is very slow.

Question 60

Aquatic insects sometimes have evaginations of the body surface called _______ that are densely supplied with trachea and covered with a thin cuticle.

A) gills
B) book lungs
C) tracheal gills
D) spiracles

Question 61

Describe a bimodal breather and the advantages that bimodal breathing can offer an animal.

Question 62

The O₂ partial pressure in the blood leaving a breathing organ is considered the best single measure of the breathing organ's effectiveness. Why is the partial pressure of blood going toward the breathing organ not an effective measure?

Question 63

Compare and contrast cocurrent gas exchange with countercurrent gas exchange and indicate which is more efficient.

Question 64

Several morphological features of the bird respiratory system allow for more efficient gas exchange. Describe these features.

Question 65

What are the major stimuli for increasing ventilation in fish?

Question 66

Compare and contrast the uptake of O₂ and the excretion of CO₂ in bullfrog tadpoles and adults.

Question 67

Describe the quality of the gas within the alveoli of the mammalian lung and explain how it differs from atmospheric air.

Question 68

How do both CO₂ and H⁺ stimulate ventilation in mammals?

Question 69

Describe the physiological advantages of the bird respiratory system that make it more efficient than the mammalian system.

Question 70

How do insects combat the evaporative water loss that is inherent in a tracheal system?