Deck 31: Breathing

Question 1

_______ describes bulk flow of air or water between the gas exchange membranes in an animal and the outside world.

A) Diffusion
B) Breathing
C) External respiration
D) Ventilation
E) Cellular respiration

Answer 1

D

Question 2

If the partial pressure of oxygen in the blood is lower than the partial pressure of oxygen in the body's tissues,

A) oxygen will diffuse out of the blood into the tissues.
B) oxygen will diffuse into the blood from the tissues.
C) carbon dioxide will diffuse into the blood from the tissues.
D) there will be no diffusion of gases between the tissues and the blood.
E) oxygen will be pumped from the blood into the tissues via active transport.

Answer 2

B

Question 3

August Krogh determined that the maximum distance over which O₂ can flow across a tissue or tissue fluids and still meet the metabolic demands of the organism is

A) 0.05 mm.
B) 0.5 mm.
C) 5.0 mm.
D) 50.0 mm.
E) 5.0 cm.

Answer 3

B

Question 4

If oxygen is moving between a liquid and a gas,which factor is the most important in determining the direction in which that oxygen will diffuse?

A) Difference in the concentration of the oxygen in the liquid and the gas
B) Length of the diffusion path
C) Difference in the partial pressure of the oxygen in the liquid and the gas
D) Volume of the liquid
E) Surface area of the liquid

Question 5

The respiratory gases of animals are

A) carbon dioxide and water vapor.
B) oxygen and nitrogen.
C) nitrogen and carbon dioxide.
D) oxygen and carbon dioxide.
E) oxygen and water vapor.

Question 6

If the partial pressure of oxygen in the blood is higher than the partial pressure of oxygen in the body's tissues,

A) oxygen will diffuse out of the tissues into the blood.
B) oxygen will diffuse into the tissues from the blood.
C) carbon dioxide will diffuse into the tissues from the blood.
D) there will be no diffusion of gases between the tissues and the blood.
E) oxygen will be pumped from the blood into the tissues via active transport.

Question 7

The rate at which a gas diffuses between two locations is _______ the distance between those locations.

A) unrelated to
B) positively related to
C) the square root of
D) inversely related to
E) None of the above

Question 8

All animals undergoing cellular respiration must get rid of CO₂ because

A) as CO₂ increases,it interferes with lung function.
B) as CO₂ increases,it makes body fluids more acidic.
C) as CO₂ increases,it decreases brain function.
D) as CO₂ increases,it is less able to be stored as sugar.
E) CO₂ is incredibly toxic.

Question 9

Breathing provides the body with the oxygen required to support the energy metabolism of all cells and also eliminates _______,one of the waste products of cell metabolism.

A) carbon dioxide
B) carbon monoxide
C) carbon tetrachloride
D) calcium carbonate
E) carbonic acid

Question 10

The partial pressure of oxygen in a pond is lower than the partial pressure of oxygen in the air above the pond.The concentration of oxygen in the pond is higher than in the air.Under these conditions,

A) the oxygen will move into the pond.
B) the oxygen will move out of the pond.
C) there will be no movement of oxygen.
D) the oxygen will move concurrently with carbon dioxide.
E) the oxygen will move into the trees surrounding the pond.

Question 11

At sea level,O₂ makes up about _______ percent of the gas molecules in the air.

A) 1
B) 15
C) 21
D) 70
E) 100

Question 12

Many tiny _______ are believed to breathe by diffusion rather than ventilation.

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

Question 13

In your own body,which pathway is an example of the longest path an O₂ molecule must take to arrive at its destination?

A) From the nose to the lungs
B) From the alveoli to the capillaries in the lungs
C) From the capillary blood of the lungs to an erythrocyte
D) From the lungs to a calf muscle
E) From the tissue capillaries to a muscle cell

Question 14

Suppose the partial pressure of oxygen is measured in a region of your body.The readings indicate that the partial pressure of oxygen in the blood is 40 mm Hg and the partial pressure of oxygen in the surrounding tissue is 100 mm Hg.The region where these readings were taken is most likely in your

A) liver.
B) skeletal muscle.
C) heart.
D) lungs.
E) kidneys.

Question 15

Humans have difficulty obtaining enough oxygen while breathing at high elevations because _______ at low elevations.

A) CO₂ makes up a higher percentage of the air than it does
B) the temperature is lower than it is
C) the barometric pressure is higher than it is
D) the air is drier than it is
E) the partial pressure of O₂ is lower than it is

Question 16

Gas exchange in animals always involves

A) lungs.
B) breathing movements.
C) neural control.
D) diffusion between internal body fluids and the outside medium.
E) active transport of gases.

Question 17

According to Fick's law,which event would cause a decrease in the rate of diffusion?

A) A decrease in the size of the respiratory membrane (A)
B) A decrease in the distance (L)between the two surfaces
C) An increase in the partial pressure difference of the gas at its two locations (P₁ - P₂)
D) An increase in the size of the respiratory membrane (A)
E) None of the above

Question 18

If you were atop Mt.Everest,where 21 percent of the molecules in the air are O₂ and the partial pressure of oxygen is one-third that at sea level,approximately how many cubic meters of air would you need to breathe to gain the same number of oxygen molecules that you would gain from one cubic meter of air at sea level?

A) 1
B) 3
C) 5
D) 6
E) 9

Question 19

The gas exchange membranes of an animal consist of one to two layers of

A) adipose tissue.
B) epithelial tissue.
C) nervous tissue.
D) muscle.
E) connective tissue.

Question 20

Oxygen is exchanged between the body fluids of an animal and its environment by

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

Question 21

Bird and fish respiratory systems are similar in that both

A) employ a countercurrent exchanger.
B) have air sacs.
C) function by means of unidirectional flow of the environmental medium over the gas exchange membranes.
D) consist of infoldings of the body.
E) involve opercular flaps.

Question 22

The table below shows data on oxygen concentration in water and the use of oxygen by fish at different water temperatures.What is one conclusion that can be drawn from these data?

A) The solubility of oxygen in water increases as the temperature of the water increases.
B) An inactive fish uses less oxygen during respiration when its body temperature is warmer.
C) An active fish uses less oxygen than an inactive fish at higher water temperatures.
D) Both active and inactive fish use oxygen at higher rates in warm water than they do in cold water.
E) As water temperatures drop the amount of dissolved oxygen in the water decreases.

Question 23

What would be an expected outcome of a drop in water temperature in a pond?

A) An increase in the metabolism of fish living in the pond
B) A decrease in the amount of O₂ in the water
C) Increased blood flow in the fish living in the pond
D) Decreased O₂ consumption of the fish living in the pond
E) An increase in body temperature of the fish living in the pond

Question 24

Which is not an example of bulk flow of oxygen?

A) Wind blowing
B) Ventilation
C) Water currents
D) Flow of blood from the lungs through the blood vessels
E) Movement of oxygen from the lungs into the blood stream

Question 25

As water exits the gill cavity of fish,

A) the partial pressure of oxygen is higher than when it entered.
B) the partial pressure of oxygen is lower than when it entered.
C) the partial pressure of carbon dioxide is lower than when it entered.
D) it is colder than when it entered.
E) it is completely depleted of oxygen.

Question 26

Aquatic animals that lack specialized internal organs for transporting respiratory gases

A) may have flat,leaflike bodies.
B) get rid of CO₂ by diffusion.
C) may have cells organized around extensive internal passageways through which water circulates.
D) have cells that are all close to the respiratory medium.
E) All of the above

Question 27

Which statement about respiratory adaptations is false?

A) Internalization of respiratory surfaces leads to the need for ventilation.
B) External gills are found only in invertebrates.
C) Some fishes ventilate their gills by swimming with their mouths open.
D) In fish,water flows unidirectionally into the mouth,over the gills,and out from under the opercular flaps.
E) Desiccation of the respiratory surface is more likely to occur in lungs than in gills.

Question 28

Which group of animals lacks specialized breathing organs?

A) Mammals
B) Sponges
C) Reptiles
D) Insects
E) Fish

Question 29

Oxygen can be exchanged more easily in air than in water because

A) more energy is required to move air than water.
B) oxygen diffuses more rapidly in water than in air.
C) the oxygen content of air is higher than that of water.
D) air temperature is usually higher than water temperature.
E) Both a and b

Question 30

Which of the following characterizes the lungs of most terrestrial vertebrates?

A) Air sacs
B) Tidal ventilation
C) Complete emptying in exhalation
D) Crosscurrent airflow
E) Countercurrent airflow

Question 31

Rapid gas exchange can be accomplished more easily in air than in water because

A) the O₂ content of water is higher than that of air.
B) the CO₂ content of water is higher than that of air.
C) O₂ diffuses more rapidly in water than in air.
D) water is more dense and viscous than air.
E) more energy is required to move air than to move water.

Question 32

Which statement about the structure of the fish gill is false?

A) Afferent vessels bring blood to the gills and efferent vessels take blood away from the gills.
B) Exchange of respiratory gases occurs within the lamellae of the gill filaments.
C) The efferent and afferent vessels are the countercurrent flow system of the gills.
D) The lamellae greatly increase the surface area for gas exchange.
E) The opercular flaps cover the gill chambers.

Question 33

The delicate gills of fishes are supported by _______ and _______.

A) opercular flaps;gill arches
B) opercular flaps;gill filaments
C) gill filaments;gill arches
D) opercular flaps;a diaphragm
E) gill arches;a diaphragm

Question 34

Which group of animals has a respiratory system that involves countercurrent exchange?

A) Mammals
B) Sponges
C) Reptiles
D) Insects
E) Fish

Question 35

Which animal exhibits tidal ventilation?

A) Lobster
B) Shark
C) Catfish
D) Planarian
E) Turtle

Question 36

Which is not an adaptation seen in fish gills?

A) A countercurrent exchange system
B) Bidirectional ventilation
C) Morphological features that increase the surface area available for gas exchange
D) Morphological features that decrease the path length for diffusion of the respiratory gases
E) Morphological features that maximize the efficiency of O₂ extraction

Question 37

The rate of gas exchange in mammals is maximized by

A) an exceedingly high partial pressure of O₂ in the blood.
B) the opening of the larynx (voice box)into the trachea.
C) an enormous surface area for gas exchange.
D) the relatively small increase in size of the thoracic cavity during inhalation.
E) the use of mucus as a surfactant.

Question 38

Which statement about gills is false?

A) The respiratory membrane has a large surface area.
B) They are found in aquatic organisms.
C) They are folded outward from the body.
D) They are surrounded by the environmental medium.
E) They contain the environmental medium.

Question 39

Which animal exhibits unidirectional ventilation?

A) Lobster
B) Rabbit
C) Frog
D) Rattlesnake
E) Turtle

Question 40

Which is not one of the factors that accounts for the efficiency of gas exchange in fish gills?

A) Maximized surface area
B) Minimized path length for diffusion
C) Countercurrent flow of blood and water over opposite sides of the gas exchange surfaces
D) Great numbers of secondary lamellae
E) One-way flow of water coming in through the gills and exiting through the mouth

Question 41

Which sequence represents the correct pathway of air during inhalation in mammals?

A) Pharynx,larynx,trachea,bronchi,alveoli
B) Larynx,trachea,pharynx,bronchi,alveoli
C) Trachea,larynx,pharynx,bronchi,alveoli
D) Trachea,larynx,pharynx,alveoli,bronchi
E) Pharynx,trachea,bronchi,larynx,alveoli

Question 42

In the respiratory cycle of birds,inhaled air flows through the trachea,to the bronchi,and then

A) into the parabronchi and posterior air sacs.
B) back through the trachea.
C) to the air capillaries.
D) into the parabronchi and anterior air sacs.
E) into the anterior air sacs.

Question 43

Which term represents the volume of your normal breath?

A) Resting tidal volume
B) Residual volume
C) Respiratory minute volume
D) Vital capacity
E) Total lung capacity

Question 44

If you are healthy,the blood and air in your alveoli are only about _______ $\mu$ m apart,which promotes rapid diffusion of respiratory gases.

A) 0.05
B) 0.5
C) 5.0
D) 50.0
E) 500.0

Question 45

Which statement about lung surfactant is true?

A) It is found in reptiles,amphibians,and mammals.
B) It reduces the surface tension at the surfaces of lung epithelium.
C) It is composed of proteins and lipids.
D) It helps stabilize the three-dimensional structure of gas exchange membranes.
E) All of the above

Question 46

The _______ serve(s)as a joint passageway for air and food.

A) alveoli
B) bronchi
C) bronchioles
D) pharynx
E) trachea

Question 47

Maximal tidal volume is about _______ times the resting tidal volume.

A) 2
B) 6
C) 10
D) 12
E) 20

Question 48

In the following equation,which quantity represents the volume of your normal breath at rest? Total lung capacity = residual volume + expiratory reserve volume + inspiratory reserve volume + tidal volume

A) Total lung capacity
B) Residual volume
C) Expiratory reserve volume
D) Inspiratory reserve volume
E) Tidal volume

Question 49

Which structure is not part of the conducting airways in a mammal?

A) Trachea
B) Larynx
C) Primary bronchi
D) Respiratory bronchioles
E) Secondary bronchi

Question 50

Which structure(s)is/are a site of gas exchange in mammalian lungs?

A) Pharynx
B) Primary bronchi
C) Secondary bronchi
D) Trachea
E) Alveoli

Question 51

The gas exchange system of _______ includes air sacs that interact with the lungs,and air flowing unidirectionally through parabronchi.

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

Question 52

The respiratory system of insects consists of

A) branched air tubes called spiracles that supply capillaries.
B) branched air tubes called tracheae that open to the atmosphere through spiracles.
C) branching gill systems that end in openings called tracheae.
D) branching gill systems that end in openings called spiracles.
E) extensive layers of gas exchange tissue just under the exoskeleton.

Question 53

Air sacs of the avian respiratory system can be grouped into _______ air sacs.

A) lateral and ventral
B) anterior and posterior
C) posterior and ventral
D) lateral and dorsal
E) anterior and ventral

Question 54

If a new air pollutant were to damage the surfactant in people's lungs,one likely result would be

A) decreased surface tension of the fluid lining their alveoli.
B) increased uptake of CO₂ from the environment.
C) increased effort needed to breathe.
D) decreased levels of hydrogen bonding in the fluid of their alveoli.
E) Both a and c

Question 55

Which statement about the air sacs of birds is false?

A) They connect to airways in the lungs.
B) They are structured as anterior and posterior pairs.
C) They make the bird's respiratory system more efficient than a mammal's.
D) They allow for one-way airflow through the lungs.
E) They provide an extra gas exchange surface.

Question 56

In birds,upon exhalation,air sacs are _______,air passes through the _______,and it then passes out through the _______.

A) filled with air;anterior air sac;bronchi
B) contracted;posterior air sac;trachea
C) expanded;parabronchi;bronchi
D) compressed;lungs;trachea
E) expanded;bronchi;trachea

Question 57

Which organism does not require both external ventilation of its respiratory surfaces with the medium containing O₂ and internal ventilation of its respiratory surfaces with blood?

A) Crayfish
B) Rabbit
C) Insect
D) Fish
E) Bird

Question 58

Which statement about insect respiration is false?

A) Spiracles are the internal air tubes that carry the respiratory gases.
B) Because O₂ diffuses more quickly in air than in water,the insect respiratory system is highly efficient.
C) Tracheae have such extensive branching that they come close to every cell.
D) Air sacs found in many insects can be used to ventilate the tracheae.
E) Tracheae are lined with chitin.

Question 59

In mammals,the respiratory structure(s)that carry air into the lungs is/are the

A) bronchioles.
B) larynx.
C) trachea.
D) secondary bronchi.
E) primary bronchi.

Question 60

Which feature is similar in the respiratory systems of mammals and birds and distinguishes them from other terrestrial vertebrates?

A) High efficiency to support high metabolic rates
B) Unidirectional airflow
C) Air sacs
D) Parabronchi
E) Lung flexibility

Question 61

The caudal (posterior)side of the mammalian thoracic cavity is formed by the

A) diaphragm.
B) esophagus.
C) stomach.
D) ribs.
E) intercostal muscles.

Question 62

Since there are no active transport mechanisms for respiratory gases,they can be exchanged only by _______.

Question 63

Which statement about human breathing is true?

A) The volume of the thoracic cavity does not change.
B) You contract all your intercostal muscles to help expel air from your lungs.
C) You relax your diaphragm when you breathe in.
D) For a person at rest,less energy is expended for exhalation than for inhalation.
E) The thoracic cavity contracts during inhalation.

Question 64

The breathing centers in humans initiate ventilation in response to

A) a decrease in air pressure.
B) a decrease in O₂ partial pressure in the blood.
C) an increase in CO₂ partial pressure in the blood.
D) the time since the last breath.
E) the rate of gas exchange in the alveoli.

Question 65

In mammals,nodes that are sensitive to O₂ and blood pressure levels are located in the

A) aorta and carotid arteries.
B) brain stem capillaries.
C) hypothalamus.
D) pulmonary artery.
E) pulmonary vein.

Question 66

If the thoracic wall is punctured,air leaking in will cause the lung to collapse.Thus one can conclude that in the normal intact thoracic cavity,

A) lung expansion is passive.
B) air pressure is the same as it is on the outside.
C) air pressure is lower than it is on the outside,which helps keep the lungs inflated.
D) breathing movements keep the lungs inflated.
E) Both a and b

Question 67

In a mixture of gases,the portion of the total pressure exerted by any particular gas is called the _______.

Question 68

Chemoreceptors on the surface of the medulla oblongata are sensitive to

A) O₂.
B) N₂.
C) surfactant.
D) blood CO₂ partial pressure and pH.
E) None of the above

Question 69

Which is not an important factor in the control of ventilation rate?

A) Small changes in blood O₂ partial pressure
B) Small changes in blood CO₂ partial pressure
C) Blood pH
D) The medulla oblongata
E) Receptors detecting motion in muscle and joints

Question 70

The lungs in mammals expand during inhalation because

A) the diaphragm contracts upward.
B) the shoulder girdle moves upward.
C) the volume of the thoracic cavity increases.
D) lung tissue actively stretches.
E) the lung tissue rebounds from exhalation.

Question 71

The partial pressure of CO₂ in the blood is monitored carefully by the human body,and any changes lead quickly to changes in respiratory rate.Both an increase in partial pressure of CO₂ and _______ are stimuli that lead to increased respiratory gas exchange.

A) an increase in the partial pressure of N₂ in the blood
B) a decrease in the partial pressure of O₂ in the blood
C) the temperature as measured at the hypothalamus
D) increased acidity in the blood
E) a lowered pulse rate

Question 72

In studies of dogs running on treadmills,a researcher found that when the dogs were running at 3 mph,the average value of CO₂ partial pressure was 39.0 mm Hg and the average respiratory minute volume in L/min was 9.0.The treadmill speed was then increased to 6 mph;the initial recordings are shown in the tables below.You can conclude from these data that when the dogs started running at twice the speed,their

A) arterial CO₂ partial pressure was relatively unchanged.
B) arterial CO₂ partial pressure increased exponentially by a power of 2.
C) respiratory rate increased.
D) respiratory rate was unchanged.
E) Both a and c

Question 73

In mammals,centers in the brain that generate signals that control the rhythm of breathing are known as the

A) diaphragms.
B) pre-Bötzinger complexes.
C) carotid bodies.
D) aortic bodies.
E) hypoglossal nuclei.

Question 74

Breathing rhythm in mammals is generated in the

A) medulla oblongata.
B) lungs.
C) diaphragm.
D) frontal lobe.
E) cerebellum.

Question 75

In Fick's law of diffusion,the formula (P₁ - P₂)refers to the difference in the _______ of a gas at two locations.

Question 76

The carotid and aortic bodies of mammals

A) respond to significant drops in the blood O₂ partial pressure.
B) are blood vessels.
C) detect minor fluctuations in heart rate.
D) are electrosensors.
E) are located in the left ventricle of the heart.

Question 77

Which statement about human breathing is true?

A) It involves countercurrent gas exchange.
B) With maximum inhalation,a person can breathe in as much air as the lungs can hold.
C) A residual volume of air remains in the lungs even with maximum exhalation.
D) There is a long diffusion path between the blood and the air (greater than 0.5 mm).
E) The partial pressure of O₂ within the alveoli is the same as that of the external air.

Question 78

In mammals,neural control of breathing is a function of the

A) cerebrum.
B) diaphragm.
C) medulla oblongata.
D) olfactory lobe.
E) spinal cord.

Question 79

In studies of dogs running on treadmills,results stemming from a gradual increase in the slope of the treadmills supported the hypothesis that the partial pressure of CO₂ is the feedback signal controlling respiratory rate.However,a related experiment that did not support that hypothesis

A) compared respiratory rates of dogs versus cats.
B) compared sleeping versus barking dogs.
C) changed the speed at which the dogs ran instead of the slope of the treadmills.
D) changed the dogs' motivation by keeping them food-stressed.
E) involved the injection of dissolved O₂ into the dogs' arteries.

Question 80

When you are at rest,the process of exhalation involves

A) the contraction of all your intercostal muscles.
B) elastic recoil of your lung tissues.
C) the contraction of your diaphragm.
D) complete collapse of your lung tissue.
E) low pressure in your thoracic cavity.