Deck 46: Gas Exchange: the Respiratory System

Question 1

The ____ cells are most sensitive to reduced O₂ levels. ​

A)heart
B)kidney
C)liver
D)brain
E)pancreatic

Answer 1

D

Question 2

Diffusion of respiratory gases is enhanced by ____. ​

A)a large surface area
B)a thick epithelial layer
C)cool temperatures
D)the presence of active transport pumps
E)the presence of carbon dioxide

Answer 2

A

Question 3

The ____ are respiratory structures composed of moist evaginations. ​

A)tracheal tubes
B)lungs ​
C)gills
D)skin
E)nasal passages

Answer 3

C

Question 4

The ____ are air-filled respiratory system structures common in insects. ​

A)gills
B)tracheal tubes
C)lungs
D)integumentary surfaces
E)air sacs

Question 5

Amphibians often use ____ as a respiratory surface. ​

A)skin ​
B)a tracheal system
C)internal gills
D)external gills
E)scales

Question 6

As elevation increases, O₂ ____. ​

A)availability increases ​
B)availability decreases
C)availability remains constant
D)levels increase, but there is none present above 20,000 feet
E)levels decrease, until there is none present above 20,000 feet

Question 7

Why does countercurrent exchange optimize gas exchange across some gills? ​

A)It sustains an optimal thermal environment for gas exchange.
B)It optimizes perfusion to the respiratory surface.
C)It sustains an optimal respiratory gas concentration gradient, allowing diffusion to occur across the entire respiratory surface.
D)It optimizes delivery of the respiratory medium to the respiratory surface.
E)It minimizes the area of diffusion.

Question 8

Choose the correct order of tracheal system structures from most external to most internal.

A)spiracles, tracheae, tracheal branches, tracheoles
B)tracheoles, tracheae, tracheal branches, spiracles
C)tracheoles, tracheal branches, tracheae, spiracles
D)spiracles, tracheal branches, tracheae, tracheoles
E)spiracles, tracheoles, tracheae, tracheal branches

Question 9

Planes maintain an atmospheric pressure equivalent to about 8,000 feet to sustain ____. ​

A)a stable temperature
B)oxygen levels ​
C)oxygen availability
D)oxygen levels and availability
E)oxygen availability and reduce buildup of carbon dioxide

Question 10

Water is an optimal respiratory medium because ____. ​

A)water holds less O₂ than air ​
B)O₂ concentration in water is affected by solute concentration
C)the density of water allows maximal ventilation over the respiratory surface
D)O₂ concentration in water increases at higher temperatures
E)water keeps the respiratory surface wetted

Question 11

Which respiratory surface lacks physical protection from the external environment? ​

A)tracheal system tubes
B)human lungs
C)external gills
D)internal gills
E)bird lungs

Question 12

In aquatic animals, the most disadvantaged in terms of respiratory media are those living in ____. ​

A)cold saltwater
B)cold freshwater
C)warm saltwater
D)warm freshwater
E)warm brackish water

Question 13

Gas exchange between the air and a cell in an insect tracheal system occurs at the ____. ​

A)trachea ​
B)tracheal branches
C)gill filaments
D)tracheoles
E)spiracles

Question 14

Countercurrent exchange allows for the removal of ____ percent of O₂ from water flowing over gills. ​

A)50 - 60 ​
B)60 - 70
C)70 - 80
D)80 - 90
E)90 - 100

Question 15

In humans, ____ is involved in both cellular and physiological respiration. ​

A)the circulatory system
B)the respiratory surface
C)mitochondria
D)the respiratory medium
E)blood

Question 16

The process of ____ is the exchange of gases between a respiratory surface and the circulatory system. ​

A)ventilation
B)cellular respiration
C)perfusion
D)bulk flow
E)physiological respiration

Question 17

Air is the least optimal respiratory medium because ____. ​

A)air flow increases evaporation of water from the respiratory surface
B)air contains 30 times as much O₂ as water
C)air is 1000 times less dense than water
D)air requires more energy to ventilate over the respiratory surface
E)O₂ diffuses more rapidly in air than in water

Question 18

The ____ represent an internal respiratory system. ​

A)skin folds on an amphibian
B)broad, flat body of a flatworm
C)branched gill filaments
D)folds within human lungs
E)gills on a salamander

Question 19

O₂ is transported from air in the lungs into the blood through the process of ____. ​

A)active transport ​
B)simple diffusion
C)facilitated diffusion
D)osmosis
E)active transport

Question 20

Why is proper ventilation important for a respiring animal? ​

A)It directly increases gas exchange between the blood and cells. ​
B)It maintains proper O₂ and CO₂ levels on the external side of the respiratory surface so diffusion across it can be maintained.
C)It maintains blood circulation within the body of an animal.
D)It maintains proper O₂ and CO₂ levels on the internal side of the respiratory surface so diffusion across it can be maintained.
E)It directly maintains proper O₂ and CO₂ levels in tissues.

Question 21

The ____ are the initial branches of the trachea that lead into each lung. ​

A)bronchioles
B)alveoli ​
C)pleura
D)bronchi
E)larynx

Question 22

During resting exhalation in humans, the diaphragm ____ and the internal intercostal muscles ____. ​

A)contracts; relax ​
B)relaxes; contract
C)contracts; contract
D)relaxes then contracts; contract then relax
E)relaxes; relax

Question 23

The ____ is/are responsible for closing off the airway during swallowing. ​

A)larynx
B)epiglottis
C)pharynx
D)intercostal muscles
E)pleura

Question 24

During forceful exhalation, the ____ muscles contract. ​

A)diaphragm and abdominal
B)external intercostal
C)internal intercostal
D)diaphragm and external intercostal
E)diaphragm and internal intercostal

Question 25

Air movement to the mammalian respiratory surfaces can be reduced when smooth muscle in the walls of the ____ contract(s). ​

A)epiglottis
B)bronchioles
C)large bronchi
D)trachea
E)aorta

Question 26

The ____ changes during exercise. ​

A)residual volume
B)tidal volume
C)vital capacity
D)lung capacity
E)lung volume

Question 27

During exhalation, the chest cavity ____ in size, which causes air pressure in the lungs to ____. ​

A)increases; increase
B)decreases; decrease
C)increases; decrease
D)decreases; increase
E)expands; remain the same

Question 28

During human inhalation, the diaphragm ____ and the external intercostal muscles ____. ​

A)contracts; relax
B)relaxes; contract
C)contracts; contract
D)relaxes; relax
E)expands; vibrate

Question 29

Air becomes deoxygenated during the ____ of a bird's respiratory cycle. ​

A)first inhalation
B)first exhalation
C)second inhalation
D)second exhalation
E)third exhalation

Question 30

Airways of the mammalian respiratory system function to ____. ​

A)filter oxygen from carbon dioxide
B)moisten external air
C)cool external air
D)filter water out of the air
E)keep water out of the lungs

Question 31

The ____ in the mammalian airway acts as the "windpipe". ​

A)bronchus ​
B)trachea
C)larynx
D)bronchiole
E)pharynx

Question 32

The ____ drives inhalation by stimulating contraction of the diaphragm and intercostal muscles. ​

A)ventral interneuron group
B)pons interneuron groups
C)carotid bodies
D)dorsal respiratory group
E)aortic bodies

Question 33

A ____ uses positive pressure breathing to ventilate its lungs. ​

A)bird
B)frog
C)dog
D)reptile
E)human

Question 34

The respiratory surfaces of mammalian lungs are called ____. ​

A)alveoli
B)bronchi
C)tracheae
D)bronchioles
E)air sacs

Question 35

Among air breathing animals, birds have the most effective mechanism of extracting oxygen from air because ____. ​

A)birds utilize crosscurrent exchange ​
B)bird lungs have more surface area
C)bird lungs are the largest among vertebrates
D)the air sacs provide additional respiratory surfaces
E)birds utilize positive force exchange

Question 36

A ____ uses air sacs to ventilate its lungs. ​

A)human ​
B)bird
C)frog
D)reptile
E)horse

Question 37

The ____ keeps the lungs from completely deflating, even after a maximal exhalation. ​

A)residual volume ​
B)tidal volume
C)vital capacity
D)lung capacity
E)lung volume

Question 38

The ____ stimulates forceful inhalation and exhalation. ​

A)ventral interneuron group
B)pons interneuron groups
C)carotid bodies
D)dorsal respiratory group
E)aortic bodies

Question 39

The primary muscle(s)involved in human breathing is/are the ____. ​

A)external intercostals ​
B)internal intercostals
C)diaphragm
D)abdominal wall
E)lung

Question 40

The concentration of ____ has the greatest influence on the regulation of breathing rate. ​

A)O₂
B)CO₂
C)H⁺
D)N₂
E)CO

Question 41

An example of local control over breathing is ____.

A)automated lung ventilation and perfusion adjustments to changing O₂ levels in the blood ​
B)the aortic bodies signaling an increase in breathing rate when blood pH is acidic
C)refinement by the interneuron groups of the pons of contractions involved in inhalation and exhalation
D)the carotid bodies signaling an increase in breathing rate when O₂ levels are low
E)the ventral group of interneurons signaling an increase in breathing rate and depth during exercise

Question 42

Decreases in CO₂ concentration result in ____. ​

A)faster breathing ​
B)deeper breathing
C)faster and deeper breathing
D)slower and more shallow breathing
E)slower breathing

Question 43

During a dive, a marine mammal experiences an increase in the partial pressure of dissolved gases of about 1 atmosphere for every ____ meter(s)in depth. ​

A)1 ​
B)5
C)10
D)15
E)20

Question 44

As altitude increases, ____. ​

A)P_O2 increases ​
B)P_O2 decreases
C)P_CO2 increases
D)P_CO2 decreases
E)P_N2 increases

Question 45

As oxygenated blood enters tissue capillaries, the oxygen ____. ​

A)binds more tightly to hemoglobin
B)diffuses from blood plasma into body cells
C)diffuses from interstitial fluid into blood plasma
D)acts as a substrate for carbonic anhydrase
E)reaches equilibrium in blood plasma and interstitial fluid

Question 46

CO₂ is transported in the blood ____. ​

A)dissolved in the plasma exclusively
B)as bicarbonate ions exclusively
C)bound to hemoglobin exclusively
D)dissolved in the red blood cells exclusively
E)dissolved in the plasma, as bicarbonate ions, and bound to hemoglobin

Question 47

What would you predict would happen in an area of the body where P_O2 is relatively low? ​

A)O₂ would bind more readily to hemoglobin ​
B)CO₂ would bind more readily to hemoglobin
C)O₂ would release from hemoglobin
D)CO₂ would release from hemoglobin
E)binding of O₂ by hemoglobin would cease

Question 48

Most O₂ is transported in the blood ____. ​

A)dissolved in the plasma ​
B)as bicarbonate ions
C)bound to hemoglobin
D)as carbon dioxide
E)bound to bicarbonate ions

Question 49

Some deer mice are physiologically adapted to live at high altitudes because ____. ​

A)adults maintain fetal forms of hemoglobin
B)of mutations in hemoglobin that increase its oxygen-binding affinity
C)of mutations in myoglobin that increase its oxygen-binding affinity
D)of mutations that increase heart rates
E)of mutations that decrease heart rates

Question 50

Living at high altitudes can cause ____ as a respiratory adaptation. ​

A)elevated erythrocyte count ​
B)decreased number of alveoli
C)decreased number of lung capillaries
D)hemoglobin molecules with less affinity for O₂
E)decreased erythrocyte count

Question 51

The number-one risk factor for sudden infant death syndrome (SIDS)is ____. ​

A)an infant lying on their back
B)breast feeding an infant
C)premature feeding of solid foods
D)exposure to tobacco smoke
E)holding the infant

Question 52

Which event occurs in the lungs? ​

A)Free H⁺ binds to hemoglobin.
B)Plasma HCO₃ ^- enters erythrocytes.
C)CO₂ and H₂O are converted into HCO₃ ^- and H⁺ in the plasma.
D)Carbonic anhydrase converts CO₂ and H₂O into HCO₃ ^- and H⁺ in erythrocytes.
E)CO₂ binds to hemoglobin.

Question 53

Victims of CO poisoning turn "classic cherry red" in ____ percent of cases. ​

A)90
B)50
C)20
D)2
E)0

Question 54

The ____ are most sensitive to changes in CO₂. ​

A)aortic bodies
B)carotid bodies
C)receptors of the medulla
D)receptors of the aorta
E)medulla bodies

Question 55

Traveling to a high altitude can result in "altitude sickness;" however, the body eventually adjusts through ____. ​

A)increased hemoglobin circulation ​
B)decreased erythrocyte production
C)increased secretion of erythropoietin
D)decreased hemoglobin circulation
E)decreased secretion of erythropoietin

Question 56

Hemoglobin binds strongest to ____. ​

A)oxygen
B)carbon monoxide
C)carbon dioxide
D)carbonic acid
E)bicarbonate ions

Question 57

The function of carbonic anhydrase is to increase the rate ____. ​

A)of conversion of CO₂ and H₂O into HCO₃ ^- and H⁺ ​
B)of conversion of HCO₃ ^- and H⁺ into CO₂ and H₂O
C)at which CO₂ binds to hemoglobin
D)at which O₂ binds to hemoglobin
E)of conversion of HCO₃ ^- and H⁺ into CO₂ and H₂O, and the rate at which CO₂ binds to hemoglobin

Question 58

What would you predict would happen in an area of the body where blood was relatively acidic (low pH)? ​

A)O₂ would bind more readily to hemoglobin.
B)CO₂ would bind more readily to hemoglobin.
C)O₂ would release from hemoglobin.
D)CO₂ would release from hemoglobin.
E)Binding of O₂ by hemoglobin would cease.

Question 59

If N₂ gas comprises 79 percent of atmospheric air at sea level, what is P_N2? ​

A)about 300 mm Hg ​
B)about 400 mm Hg
C)about 500 mm Hg
D)about 600 mm Hg
E)about 700 mm Hg

Question 60

A man is found dead with no marks on his body in a small enclosed furnace closet. The medical examiner rules death by hypoxia. However, the criminal investigation finds that the room has adequate air flow. What is the most reasonable explanation for the cause of death that should be investigated further? ​

A)There was too little oxygen in the room.
B)The furnace was faulty and burned up all the oxygen. ​
C)The furnace was faulty and released carbon monoxide which accumulated in the closet.
D)There was too much carbon dioxide in the room.
E)The man strangled himself but the rope disappeared.

Question 61

Marine mammals use ____ to extend dive times.  ​

A)decreased blood volume
B)increased erythrocyte count
C)increased in lung volume
D)reduced concentrations of muscle myoglobin
E)elevated circulation to nonessential organs

Question 63

Which animal uses positive pressure breathing to ventilate its lungs? ​

A)human ​
B)lizard
C)bird
D)cat
E)salamander

Question 64

Which breathing abnormalities can occur in neonatal mammals exposed to nicotine? ​

A)reduced ventilatory output
B)increased duration of apneas
C)SIDS
D)reduced ventilatory output and increased duration of apneas
E)reduced ventilatory output, increased duration of apneas, and SIDS

Question 65

Respiratory neurons from the dissected brainstem of a neonatal rodent can maintain rhythmic firing for ____ hours. ​

A)0.5
B)1.0
C)4.5
D)6.0
E)8.5

Question 69

Studies indicate that in utero nicotine exposure can cause breathing abnormalities in neonatal mammals, including ____. ​

A)elevated breathing rate while awake ​
B)increased frequency of apneas during sleep
C)delayed arousal from sleep in response to hypoxia
D)elevated breathing rate while awake and increased frequency of apneas during sleep
E)increased frequency of apneas during sleep and delayed arousal from sleep in response to hypoxia

Question 72

Changes in humans caused by high altitude exposure are ____. ​

A)always temporary
B)always permanent
C)temporary or permanent depending on duration of exposure
D)temporary or permanent depending on developmental timing of exposure
E)temporary or permanent depending on duration and developmental timing of exposure

Question 73

Which mechanism is used to encourage the movement of water over gills? ​

A)beating of cilia
B)contraction of the diaphragm
C)relaxation of a muscular mantle
D)a fish swimming with its mouth closed
E)relaxation of body muscles

Question 76

The ____ of marine mammals receives normal blood supply during deep dives. ​

A)lungs
B)heart
C)brain
D)blood vessels
E)heart, brain, and blood vessels

Question 77

Research indicates that the Tibetan and Han Chinese inherited a variant EPAS1 allele from ____. ​

A)a common Denisovan ancestor
B)interbreeding with Denisovans while still a common ancestral group
C)interbreeding with Denisovans as distinct groups with overlapping territories
D)an ancestor common to all humans
E)an ancestor shared with the Andean people

Question 78

Tibetan people have ____ in their blood despite living at high altitude. ​

A)less oxygen
B)more erythropoietin
C)less erythropoietin
D)more hemoglobin
E)less hemoglobin