Deck 48: The Respiratory System

Question 1

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

Answer 1

C

Question 2

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

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

Answer 2

C

Question 3

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

A)while running a road race along the shoreline of Vancouver
B)while hyperventilating
C)while climbing to the summit of Mt.Everest
D)while hypoventilating

Answer 3

C

Question 4

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

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

Question 5

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

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

Question 6

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)B, C, A
B)C, B, A
C)A, B, C
D)B, A, C

Question 7

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)A
C) $\Delta$ p
D)d

Question 8

The exchange of gases across a respiratory surface always occurs by

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

Question 9

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

Question 10

Which blood vessels carry oxygenated blood?

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

Question 11

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)A
C)d
D) $\Delta$ p

Question 12

The oxygen content of dry air in the atmosphere

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

Question 13

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

Question 14

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

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

Question 15

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)It is impossible for Sammy to control the contraction of his diaphragm and intercostal muscles since they are made up of smooth muscle.
B)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.
C)Sammy is too young to hold his breath for more than 30 seconds.
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 16

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

Question 17

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)respiration.
B)diffusion.
C)exhalation.
D)cellular respiration.

Question 18

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

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

Question 19

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

A)P_CO2
B)hemoglobin concentration
C)pH
D)P_O2

Question 20

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)they do not have as many papulae as echinoderms.
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.

Question 21

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)gills have a much greater diffusion surface area
C)gills decrease resistance to movement
D)all gills contain a countercurrent exchange system

Question 22

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

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

Question 23

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)the same
C)lower

Question 24

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)alveoli
B)spiracles
C)papulae
D)lamellae

Question 25

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

Question 26

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

A)spiracle
B)glottis
C)operculum
D)trachea

Question 27

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

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

Question 28

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

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

Question 29

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

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

Question 30

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

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

Question 31

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

Question 32

Which dissolved gas cannot be transported by hemoglobin?

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

Question 33

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

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

Question 34

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

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

Question 35

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

Question 36

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

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

Question 37

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

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

Question 38

Which of these animals uses positive pressure breathing?

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

Question 39

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 dead since all the hemoglobin in his arterial blood will unload its oxygen during the first pass through the tissues after his last breath.
D)Tom will be alive since he had a reserve of about three-quarters of his hemoglobin still bound to oxygen when he started choking.

Question 40

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

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

Question 41

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 -> pleural cavity -> intercostal muscles -> visceral pleural membrane -> parietal 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

Question 42

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 43

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

A)papulae
B)internal gills
C)external gills
D)lungs

Question 44

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

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

Question 45

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

A)the hydrophobic pocket between two $\alpha$ chains
B)the copper atom wedged between an $\alpha$ and a $\beta$ globin chain
C)the iron atom in the center of a heme group
D)the surface of a $\beta$ globin chain

Question 46

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 binds more tightly to hemoglobin than does oxygen.

Question 47

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

A)posterior air sacs
B)trachea
C)spiracles
D)esophagus

Question 48

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

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