Deck 47: The Respiratory System

Question 1

The exchange of gases across a respiratory surface always occurs by

A)facilitated transport.
B)active transport.
C)diffusion.
D)bulk flow.
E)osmosis.

Answer 1

C

Question 2

Ciliated gills in clams,sharks continuously swimming with their mouths partly open,countercurrent flow of blood and water in fish gills,and the use of air sacs to effect unidirectional flow of air through bird lungs are all adaptations that optimize what factor in the formula for Fick's Law of diffusion?

A)D
B)Δp
C)d
D)A

Answer 2

B

Question 3

Each breath is initiated by neurons in the "respiratory control center" located in the

A)spinal cord.
B)larynx.
C)cerebellum.
D)medulla oblongata.
E)carotid body.

Answer 3

D

Question 4

In tissue capillaries,________ combines with water to form carbonic acid,which after being transported to the lungs,dissociates back to its constituents.

A)CO₂
B)O₂
C)H₂CO₃
D)hemoglobin
E)HCO₃^-

Question 5

The oxygen content of dry air in the atmosphere

A)is about 78.1%.
B)is about 21.0%.
C)is about 0.03%.
D)varies depending on the altitude.
E)is inversely proportional to the partial pressure of oxygen.

Question 6

Fick's law of diffusion states that the rate of diffusion of a gas across a membrane depends on all of the following except

A)the membrane surface area.
B)the concentration difference of the gas on the two sides of the membrane.
C)the width of the membrane.
D)the size of the gas molecule.
E)which membrane transport proteins are present.

Question 7

Where a given species of vertebrate lives has dramatically shaped the evolution of respiratory adaptations,particularly since the oxygen concentration in air is approximately 20 times that of the oxygen concentration in water.Per unit area of gas exchange surface,which group of vertebrates can extract the greatest total amount of oxygen from the external medium?

A)amphibians
B)birds
C)fish
D)mammals
E)reptiles

Question 8

Chemoreceptors located in the aortic and carotid bodies stimulate the respiratory control center in the brain when the blood ________ decreases.

A)P_O2
B)P_CO2
C)hemoglobin concentration
D)HCO₃^- concentration
E)pH

Question 9

What would a graph of internal lung pressure compared to atmospheric pressure look like during one inhalation/exhalation cycle in a frog?

A)A
B)B
C)C
D)D
E)E

Question 10

Imagine that you have been transported light years away to another planet with water-filled oceans.This distant planet has a barometric pressure of 1,000 mm Hg at sea level and air that contains 15 percent O₂.Would you take in much more oxygen,much less oxygen,or about the same amount of oxygen per breath on this planet as you would on Earth?

A)much less oxygen on the distant planet
B)much more oxygen on the distant planet
C)about the same amount of oxygen as on Earth

Question 11

Fish and crustaceans are similar in that both use ________ for gas exchange.

A)lungs
B)tracheal tubes
C)the walls of the mantle cavity
D)gills
E)the moist surface of their skin

Question 12

The most efficient lungs with respect to oxygen uptake are found in this group of vertebrates.

A)amphibians
B)birds
C)fish
D)mammals
E)reptiles

Question 13

The general term that describes the uptake of oxygen from the environment and the disposal of carbon dioxide at the body system level is

A)cellular respiration.
B)inspiration.
C)exhalation.
D)respiration.
E)diffusion.

Question 14

In the above graph,curve ________ is most likely the oxygen-binding curve for normal adult human hemoglobin,curve ________ is most likely that of llama hemoglobin (from a llama population that has lived in the mountains of Peru for thousands of years),and curve ________ is most likely that of myoglobin.

A)A; B; C
B)A; C; B
C)B; A; C
D)B; C; A
E)C; B; A

Question 15

When is the P_O2 an especially strong stimulant of the respiratory control center in the brain of healthy individuals?

A)while hyperventilating
B)while hypoventilating
C)while running a road race along the shoreline of Vancouver
D)while climbing to the summit of Mt.Everest
E)while free-diving to a coral reef 60 feet below the surface of the sea

Question 16

In the above graph,what does the A represent?

A)anatomical dead space
B)air that helps keep the alveoli inflated (open)after forced exhalation
C)air that is not used for gas exchange
D)air with a concentration of oxygen higher than that of air outside the body
E)air from a previous breath that does not mix with newly-inhaled air of the next breath

Question 17

The external gills of an adult axolotl are not as efficient as fish gills because________.

A)water flows over the axolotl gills at many different angles
B)blood flows though the axolotl gills more slowly than through fish gills
C)axolotl gills are not highly branched
D)axolotl gills are covered by thick layers of cells
E)axolotls are slow swimmers and all fish swim fast to ventilate their gills

Question 18

The large number of alveoli in mammalian lungs,the numerous lamellae in fish gills,the papulae of echinoderms,and the extensive tracheal system of insects are all adaptations that optimize what factor in the formula for Fick's Law of Diffusion?

A)D
B)Δp
C)d
D)A

Question 19

Four-year old Sammy is having a temper-tantrum.In a final attempt to get his way,he yells to his mom,"I'm gonna hold my breath 'til I die!" What is the primary reason that Sammy's mom is unconcerned by this statement?

A)Sammy is too young to hold his breath for more than 30 seconds.
B)It is impossible for Sammy to control the contraction of his diaphragm and intercostal muscles since they are made up of smooth muscle.
C)As Sammy holds his breath,the decreasing levels of oxygen in his blood will lead to stimulation of the respiratory control center in his brain.
D)As Sammy holds his breath,the increasing levels of carbon dioxide in his blood will lead to stimulation of the respiratory control center in his brain.

Question 20

Most simple invertebrates obtain their oxygen by diffusion directly from the surrounding

A)air.
B)water.
C)mud.
D)blood.

Question 21

Which group of animals has one-way flow of air through its lungs,whereas all the others have tidal flow?

A)birds
B)amphibians
C)mammals
D)reptiles

Question 22

Humans cannot survive long at altitudes greater than 6000 m because ________.

A)alveoli become compressed at the lower atmospheric pressures
B)there is much more CO₂ in the atmosphere at the higher altitudes than at sea level
C)the partial pressure of O₂ becomes less than half that at sea level
D)the diaphragm cannot be contracted enough to produce a full breath

Question 23

Most phyla of aquatic invertebrates have improved the rate of gas exchange by creating a water current over their respiratory surfaces,thereby ________.

A)decreasing the distance for diffusion
B)increasing the surface area for diffusion
C)increasing the concentration difference
D)changing the diffusion constant

Question 24

Major evolutionary changes have resulted in anatomical and physiological adaptations that optimize the rate of gas exchange in animals by each of these factors except ________.

A)increasing the surface area for diffusion
B)increasing the concentration difference driving diffusion
C)decreasing the distance for diffusion
D)increasing the diffusion constant for each gas

Question 25

The primary advantage of gills versus the body surface for gas exchange in aquatic animals is that ________.

A)gills are located near the mouth
B)all gills contain a countercurrent exchange system
C)gills have a much greater diffusion surface area
D)gills decrease resistance to movement

Question 26

What change would increase the rate of oxygen diffusing from lung alveoli into the blood?

A)An increase in the hemoglobin concentration of the red blood cells
B)A decrease in the partial pressure of oxygen in the alveoli
C)An increase in the partial pressure of oxygen in the blood entering the lungs
D)A decrease in the pH of the blood entering the lungs
E)An increase in the humidity of air in the lungs

Question 27

Which blood vessels carry oxygenated blood?

A)pulmonary arteries
B)pulmonary veins
C)systemic veins (such as the femoral vein in your leg)

Question 28

Tom is choking on a piece of steak that is stuck in his trachea,and he signals for his young son to call 911.It takes the paramedics four minutes to reach his house.Will this be in time to save Tom (and why),or will Tom already be dead (and why)?

A)Tom will be alive since the myoglobin in his muscles will release oxygen into the blood after he stops breathing.
B)Tom will be dead due to the lowered pH of his blood.
C)Tom will be alive since he had a reserve of about three-quarters of his hemoglobin still bound to oxygen when he started choking.
D)Tom will be dead since all the hemoglobin in his arterial blood will unload its oxygen during the first pass through the tissues after his last breath.

Question 29

In the future,it may be possible to screen for a number of different types of cancer by a simple blood test.If a blood test indicates a very early stage of lung cancer,where is the most likely place that the tumor will be growing?

A)in the wall of a large bronchus
B)in the wall of an alveolus
C)in the wall of a pulmonary vein
D)in the visceral pleural membrane
E)in the parietal pleural membrane

Question 30

Soft-shelled turtles can remain submerged underwater for several hours without ventilating their lungs because ________.

A)they also have rudimentary gills
B)the partial pressure of O₂ is higher underwater
C)they can use cutaneous respiration through the soft lining of their throats
D)they can store some air in special air sacs under the shell

Question 31

During your dissection of a fish,what structure would you have to remove to see the gills?

A)operculum
B)spiracle
C)jaw bone
D)glottis
E)trachea

Question 32

The gas exchange surfaces in a mammalian lung are organized into structures that look like clusters of hollow grapes.The hollow,grape-like structures are the________.

A)spiracles
B)lamellae
C)alveoli
D)papulae
E)bronchi

Question 33

The respiratory systems of fish and birds are similar in that both________.

A)employ countercurrent exchange.
B)utilize air sacs.
C)have unidirectional flow of the environmental medium over the gas exchange surfaces.
D)have similar partial pressures of oxygen in the environmental medium.

Question 34

During an asthma attack,allergens trigger the release of histamine,which causes severe constriction of the ________.

A)bronchi
B)pleural cavities
C)larynx
D)trachea
E)rib cage

Question 35

What is the likely outcome if you were able to force water through fish gills in the opposite direction to how it normally flows over the gills?

A)The blood's oxygen concentration would not be able to exceed 50%.
B)Gas exchange would be inhibited and movement of oxygen into the blood would cease.
C)The direction of blood flow would reverse through the gills to compensate for the reversed direction of water flow.
D)The movement of carbon dioxide from the blood into the water would increase.
E)There would be no effect,and maximal oxygenation of blood would still occur.

Question 36

Which of these animals uses positive pressure breathing?

A)amphibians
B)reptiles
C)birds
D)mammals

Question 37

One possible reason that there are not any really large insects currently living on Earth is that

A)gas exchange across their moist skin surfaces cannot support the metabolic needs of a large body.
B)their lungs never evolved to be as highly branched as a mammal's.
C)their gills do not have as many lamellae as fish gills.
D)the bulk flow of air through their tracheal tubes would be more difficult the larger the body and longer the tracheal tubes.
E)they do not have as many papulae as echinoderms.

Question 38

In the countercurrent exchange in a fish's gills,the oxygen concentration is always ________ in the water than the blood along the entire pathway of each lamella.

A)higher
B)lower
C)the same

Question 39

Which dissolved gas cannot be transported by hemoglobin?

A)nitric acid (NO)
B)oxygen (O₂)
C)carbon dioxide (CO₂)
D)carbon monoxide (CO)
E)nitrogen (N₂)

Question 40

What respiratory adaptation was important for the invasion of land by arthropods?

A)cutaneous respiration in moist habitats
B)positive pressure breathing to increase gas exchange
C)the ability to close spiracles to prevent water loss
D)countercurrent exchange surrounding the trachea
E)gas- and water-permeable exoskeletons

Question 41

During exercise,the blood returning to a person's heart contains hemoglobin that is about ________ saturated.

A)3%
B)22%
C)35%
D)75%
E)97%

Question 42

Ram ventilation is used by ________ during respiration.

A)frogs
B)tuna
C)whales
D)penguins
E)salamanders

Question 43

During exhalation,the diaphragm ________.

A)contracts and moves down
B)relaxes and moves up
C)relaxes and moves down
D)contracts and moves up

Question 44

The many lamellae in the gills of fish improve respiratory efficiency by ________.

A)decreasing the distance for diffusion
B)increasing the surface area for diffusion
C)increasing the concentration difference
D)changing the diffusion constant

Question 45

What is the order of structures or spaces that a surgeon will pass through to operate on a human lung?

A)skin -> intercostal muscles -> parietal pleural membrane -> pleural cavity -> visceral pleural membrane -> lung tissue
B)skin -> intercostal muscles -> pleural cavity -> parietal pleural membrane -> visceral pleural membrane -> lung tissue
C)skin -> visceral pleural membrane -> intercostal muscles -> pleural cavity -> parietal pleural membrane -> lung tissue
D)skin -> intercostal muscles -> visceral pleural membrane -> pleural cavity -> parietal pleural membrane -> lung tissue
E)skin -> pleural cavity -> intercostal muscles -> visceral pleural membrane -> parietal pleural membrane -> lung tissue

Question 46

Protruding papulae on the surface of echinoderms improve respiratory efficiency by ________.

A)decreasing the distance for diffusion
B)increasing the surface area for diffusion
C)increasing the concentration difference
D)changing the diffusion constant

Question 47

The large number of alveoli in lungs improve gas exchange by ________.

A)decreasing the distance for diffusion
B)increasing the surface area for diffusion
C)increasing the concentration difference
D)changing the diffusion constant

Question 48

In which P_O2 environment would hemoglobin most easily release its O₂?

A)40 mm Hg
B)65 mm Hg
C)75 mm Hg
D)90 mm Hg
E)100 mm Hg

Question 49

The North American pronghorn antelope can run almost as fast as a cheetah,but unlike the cheetah,can also sustain speeds of 30-40 mph for miles.The pronghorn is about the size of a large,domestic goat.You would predict the antelope to have a ________ than the goat.

A)smaller trachea
B)higher concentration of hemoglobin
C)smaller lung volume
D)lower concentration of myoglobin
E)lower concentration of bicarbonate

Question 50

Air enters human lungs from the mouth by passing through the ________.

A)trachea
B)nasal cavities
C)spiracles
D)posterior air sacs
E)esophagus

Question 51

The axolotl,an aquatic amphibian,uses ________ for gas exchange.

A)internal gills
B)external gills
C)lungs
D)tracheal tubes
E)papulae

Question 52

Every winter,many individuals tragically die in their sleep due to faulty heaters that leak carbon monoxide (CO)during the night.How does CO poisoning lead to death?

A)CO binds more tightly to carbonic anhydrase than does carbon dioxide.
B)CO binds to oxygen,and the CO-oxygen complex cannot bind to hemoglobin.
C)CO coats the surfaces of the alveoli,preventing diffusion of oxygen into the blood.
D)CO inhibits the chemosensitive neurons in the aortic and carotid bodies.
E)CO binds more tightly to hemoglobin than does oxygen.

Question 53

Which part of a hemoglobin molecule binds to a molecule of O₂?

A)the surface of an α globin chain
B)the surface of a β globin chain
C)the iron atom in the center of a heme group
D)the copper atom wedged between an α and a β globin chain
E)the hydrophobic pocket between two α chains

Question 54

The close proximity of capillaries to the alveoli in lungs improve respiratory efficiency by ________.

A)decreasing the distance for diffusion
B)increasing the surface area for diffusion
C)increasing the concentration difference
D)changing the diffusion constant