Deck 34: Circulation and Gas Exchange

Question 1

The semilunar valves of the mammalian heart

A)are the route by which blood flows from the atria to the ventricles.
B)are found only on the right side of the heart.
C)are the attachment sites where the pulmonary veins empty into the heart.
D)are able to prevent backflow of blood in the aorta and pulmonary arteries.

Answer 1

D

Question 2

A patient with a blood pressure of 120/75,a pulse rate of 40 beats/minute,a stroke volume of 70 mL/beat,and a respiratory rate of 25 breaths/minute will have a cardiac output of

A)500 mL/minute.
B)1,000 mL/minute.
C)1,750 mL/minute.
D)2,800 mL/minute.
E)4,800 mL/minute.

Answer 2

D

Question 3

Gas exchange in the aquatic salamander known as the axolotl is correctly described as

A)active transport to move oxygen into the salamander from the water.
B)facilitated diffusion to move oxygen into the salamander from the water.
C)facilitated diffusion of carbon dioxide from the salamander into the water.
D)simple diffusion of oxygen into the salamander from the water.
E)active transport of carbon dioxide from the salamander into the water.

Answer 3

D

Question 4

Circulatory systems compensate for

A)temperature differences between the lungs and the active tissue.
B)the slow rate at which diffusion occurs over large distances.
C)the problem of communication between the nervous system and respiratory system.
D)the need fetal organisms have for maintaining an optimal body temperature.

Question 5

The set of blood vessels with the slowest velocity of blood flow is

A)the arteries.
B)the arterioles.
C)the venules.
D)the capillaries.
E)the veins.

Question 6

Kevin is sitting quietly at home reading his biology textbook.His stroke volume is 70 mL per beat,and his resting heart rate is 60 beats per minute.What is Kevin's cardiac output?

A)4)2 L/minute
B)4)2 mL/minute
C)0)42 L/minute
D)42 L/minute
E)420 L/minute

Question 7

Hemolymph is found in the circulatory system of what kind of animal?

A)grasshopper
B)dog
C)eagle
D)earthworm

Question 8

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the

A)amphibians.
B)birds.
C)fishes.
D)mammals.
E)reptiles.

Question 9

Organisms with a circulating bodily fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have

A)an open circulatory system.
B)a closed circulatory system.

Question 10

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

A)systole of the left atrium
B)diastole of the right ventricle
C)systole of the left ventricle
D)diastole of the right atrium
E)systole of the right ventricle

Question 11

To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation,an organism would need a(n)

A)open circulatory system.
B)closed circulatory system.
C)lymphatic system.
D)two-chambered heart.
E)four-chambered heart.

Question 12

Edema,or swelling,is a potentially serious medical issue where a significant increase in the amount of interstitial fluid surrounding cells and tissues occurs.If edema were to occur in the interstitial fluid surrounding the capillary beds of a human's lungs,what is the most likely outcome?

A)an increase in the amount of carbon dioxide moving from the blood to the lungs
B)an increase in the amount of oxygen moving from the lungs into the blood
C)a decrease in the amount of oxygen moving from the lungs into the blood
D)an increase of pressure that would cause the capillary beds to burst
E)a decrease in the amount of work needed for effective ventilation of the lungs

Question 13

A human red blood cell is in an artery of the left arm and is on its way to deliver oxygen to a cell in the left thumb.To travel from the artery in the left arm to the cell in the left thumb,this red blood cell must pass through

A)one capillary bed.
B)two capillary beds.
C)three capillary beds.
D)four capillary beds.

Question 14

Which of the following is the correct sequence of blood flow in reptiles and mammals?

A)left ventricle → aorta → lungs → systemic circulation
B)right ventricle → pulmonary vein → pulmocutaneous circulation
C)pulmonary vein → left atrium → left ventricle → pulmonary circuit
D)vena cava → right atrium → right ventricle → pulmonary circuit
E)right atrium → pulmonary artery → left atrium → ventricle

Question 15

Damage to the sinoatrial node in humans

A)is a major contributor to heart attacks.
B)would block conductance between the bundle branches and the Purkinje fibers.
C)would cause blood flow rate to increase.
D)would disrupt the rate and timing of cardiac muscle contractions.
E)would have a direct effect on blood pressure monitors in the aorta.

Question 16

Heart rate will increase in the presence of increased

A)apolipoproteins.
B)immunoglobulins.
C)erythropoietin.
D)epinephrine.
E)platelets.

Question 17

All of the following are present in arterioles and in capillaries except

A)fully oxygenated blood.
B)plasma in which carbon dioxide has been added.
C)a lining of endothelial cells.
D)circular smooth muscle cells.
E)white blood cells and platelets.

Question 18

Why has natural selection favored the evolution of double circulation in birds and mammals?

A)because they are larger than reptiles and amphibians
B)because they use more energy than equivalent-size reptiles and amphibians
C)because they have more viscous blood than reptiles and amphibians
D)because they cannot obtain as much oxygen from the air as reptiles and amphibians

Question 19

The set of blood vessels with the lowest blood pressure driving flow is

A)the arteries.
B)the arterioles.
C)the venules.
D)the capillaries.
E)the veins.

Question 20

In which of the following organisms does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?

A)annelids
B)molluscs
C)fishes
D)frogs
E)insects

Question 21

Vasoconstriction of blood vessels delivering blood to the gut is a likely response when an individual is

A)lying down after standing up.
B)eating a meal.
C)stressed and secreting stress hormones.
D)responding to increased blood pressure.
E)having an allergy attack with lots of histamine secretion.

Question 22

Which of the following can cause the LDL/HDL ratio to increase and thus increase the likelihood of a myocardial infarction?

A)stopping smoking
B)eating more trans fats
C)exercising more
D)taking statin drugs

Question 23

The meshwork that forms the fabric of a blood clot is

A)epinephrine.
B)fibrin.
C)thrombin.
D)prothrombin.
E)collagen.

Question 24

Air in a testing chamber is specially mixed so that its oxygen content is 20% and its overall air pressure is 500 mm Hg.What is the partial pressure of oxygen in this chamber?

A)1000 mm Hg
B)100 mm Hg
C)10 mm Hg
D)1 mm Hg

Question 25

The sun shining on a tidal pool during a hot day heats the water.As some water evaporates,the pool becomes saltier,causing

A)a decrease in its carbon dioxide content.
B)a decrease in its oxygen content.
C)an increase in its ability to sustain aerobic organisms.
D)a decrease in the water's density.
E)a decrease in the movement of the water molecules.

Question 26

Dissolved proteins in human plasma include which of the following?

A)fibrinogen only
B)hemoglobin only
C)fibrinogen and immunoglobulin only
D)hemoglobin and immunoglobulin only
E)fibrinogen,hemoglobin,and immunoglobulin

Question 27

The diagnosis of hypertension in adults is based on the

A)measurement of fatty deposits on the endothelium of arteries.
B)measurement of the LDL/HDL ratio in peripheral blood.
C)percent of blood volume made up of platelets.
D)blood pressure being greater than 140 mm Hg systolic and/or >90 diastolic.
E)number of leukocytes per mm³ of blood.

Question 28

Large proteins such as albumin remain in capillaries rather than diffusing out,resulting in the

A)loss of osmotic pressure in the capillaries.
B)development of an osmotic pressure difference across capillary walls.
C)loss of fluid from capillaries.
D)increased diffusion of CO₂.
E)increased diffusion of Hb.

Question 29

The production of red blood cells is stimulated by

A)low-density lipoproteins.
B)immunoglobulins.
C)erythropoietin.
D)epinephrine.
E)platelets.

Question 30

Small swollen areas in the neck,groin,and axillary region are associated with

A)increased activity of the immune system.
B)blood sugar that is abnormally high.
C)dehydration.
D)sodium depletion.

Question 31

Dialysis is a medical process used to treat patients whose kidney function is below normal.During dialysis,blood is removed from the body and filtered by an artificial membrane,and plasma and its proteins are separated from the cells.Dialysis patients,who will have blood withdrawn,dialyzed,and then replaced,are always weighed when they enter the facility and then weighed carefully again before they leave,because

A)even small changes in body weight may signify changes in blood volume and therefore blood pressure.
B)many people who have dialysis are diabetic and must control their weight carefully.
C)dialysis removes blood proteins,and these weigh more than other blood components.
D)dialysis is likely to cause edema,and such swelling must be controlled.

Question 32

The hormone that stimulates the production of red blood cells and the organ where this hormone is synthesized are

A)insulin and pancreas,respectively.
B)erythropoietin and kidney,respectively.
C)epinephrine and adrenal gland,respectively.
D)prothrombin and platelets,respectively.

Question 33

The plasma proteins in humans

A)maintain the blood's osmotic pressure.
B)transport water-soluble lipids.
C)carry out gas exchange.
D)undergo aerobic metabolism.
E)transport oxygen.

Question 34

Lymphedema is a disorder in which the lymphatic vessels associated with capillary beds are blocked.What will be the long-term effect of lymphedema?

A)more fluid entering the venous capillaries
B)an increase in the blood pressure in the capillary bed
C)the accumulation of more fluid in the interstitial areas
D)fewer proteins leaking out of the blood to enter the interstitial fluid
E)the area of the blockage becoming abnormally small

Question 35

In a healthy human,the typical life span of a red blood cell is

A)24 hours.
B)1 week.
C)1 month.
D)4 months.

Question 36

If,during protein starvation,the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure,then

A)hemoglobin will not release oxygen.
B)fluids will tend to accumulate in tissues.
C)the pH of the interstitial fluids will increase.
D)most carbon dioxide will be bound to hemoglobin and carried away from tissues.
E)plasma proteins will escape through the endothelium of the capillaries.

Question 37

The velocity of blood flow is the lowest in capillaries because

A)the capillary walls are not thin enough to allow oxygen to exchange with the cells.
B)the capillaries are far from the heart,and blood flow slows as distance from the heart increases.
C)the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate.
D)the systemic capillaries are supplied by the left ventricle,which has a lower cardiac output than the right ventricle.
E)the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system.

Question 38

Which organism likely has the highest systolic pressure?

A)rat
B)snake
C)human
D)rhinoceros
E)giraffe

Question 39

A species that has a normal resting systolic blood pressure of >260 mm Hg is likely to be

A)an animal that is small and compact.
B)a species that has very wide-diameter veins.
C)an animal that has a very long distance between its heart and its brain.
D)an animal that makes frequent,quick motions.

Question 40

An increased concentration of nitric oxide within a vascular bed is associated with

A)vasoconstriction.
B)vasodilation.
C)a reduction in blood flow in that region.
D)a decreased amount of blood in the capillaries of that vascular bed.

Question 41

Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because

A)water is less dense than air.
B)water contains much less O₂ than air per unit volume.
C)gills have less surface area than lungs.
D)gills allow only unidirectional transport.
E)gills collapse in air.

Question 42

At an atmospheric pressure of 870 mm Hg of 21% oxygen,the partial pressure of oxygen is

A)100 mm Hg.
B)127 mm Hg.
C)15 mm Hg.
D)182 mm Hg.
E)219 mm Hg.

Question 43

Blood pH and cerebrospinal fluid pH are affected by carbon dioxide content.This enables the organism to sense a disturbance in gas levels as

A)the brain directly measures and monitors carbon dioxide and causes breathing changes accordingly.
B)the medulla oblongata,which is in contact with cerebrospinal fluid,monitors pH and uses this measure to control breathing.
C)the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide.
D)the lungs sense changes in oxygen concentration,which causes the medulla oblongata to speed up or slow breathing.
E)the medulla oblongata is able to control the concentration of bicarbonate ions in the blood.

Question 44

At sea level,atmospheric pressure is 760 mm Hg.Nitrogen gas is approximately 78% of the total gases in the atmosphere,so the approximate partial pressure of nitrogen is

A)5)9 mm Hg.
B)59.2 mm Hg.
C)76 mm Hg.
D)160 mm Hg.
E)592.8 mm Hg.

Question 45

Sponges,cnidarians,and flatworms lack a specialized gas-exchange surface because

A)they are too large for a circulatory system to operate well.
B)they live without the need for oxygen.
C)they do not produce carbon dioxide.
D)countercurrent exchange mechanisms cannot function well in their living conditions.
E)nearly all of their cells are in direct contact with the external environment.

Question 46

What happens to pH and breathing rate during exercise?

A)pH decreases,which causes breathing rate to increase.
B)pH decreases,which causes breathing rate to decrease.
C)pH increases,which causes breathing rate to increase.
D)pH increases,which causes breathing rate to decrease.

Question 47

The amount of air inhaled and exhaled in a normal breath is called

A)residual volume.
B)vital capacity.
C)tidal volume.
D)stroke volume.

Question 48

At the summit of a high mountain,the atmospheric pressure is 380 mm Hg.If the atmosphere is still composed of 21% oxygen,then the partial pressure of oxygen at this altitude is

A)0 mm Hg.
B)80 mm Hg.
C)160 mm Hg.
D)380 mm Hg.
E)760 mm Hg.

Question 49

Countercurrent exchange is evident in

A)the flow of water across the gills of a fish and that of blood within those gills.
B)the flow of blood in the dorsal vessel of an insect and that of air within its tracheae.
C)the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins.
D)the flow of water across the skin of a frog and that of blood within the ventricle of its heart.
E)the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary.

Question 50

The exhalation of air from human lungs is driven by

A)a decrease in the volume of the thoracic cavity.
B)a decrease in the residual volume of the lungs.
C)the contraction of the diaphragm.
D)the closure of the mouth.
E)the expansion of the rib cage.

Question 51

In mammals,most gas exchange between the atmosphere and the pulmonary blood occurs in the

A)trachea.
B)larynx.
C)bronchi.
D)bronchioles.
E)alveoli.

Question 52

Some human infants,especially those born prematurely,suffer serious respiratory failure because of

A)the overproduction of surfactants.
B)the incomplete development of the lung surface.
C)lung collapse due to inadequate production of surfactant.
D)mutations in the genes involved in lung formation.

Question 53

Countercurrent exchange in the fish gill helps to maximize

A)endocytosis.
B)blood pressure.
C)diffusion.
D)active transport.
E)osmosis.

Question 54

Air-breathing insects carry out gas exchange

A)in their specialized external gills.
B)in their specialized internal gills.
C)in the alveoli of their lungs.
D)across the finest branches of the trachea and cell membranes.
E)across all parts of their thin exoskeleton.

Question 55

Breathing is usually regulated by

A)erythropoietin levels in the blood.
B)the concentration of red blood cells.
C)hemoglobin levels in the blood.
D)CO₂ and O₂ concentration and pH-level sensors.
E)the lungs and the larynx.

Question 56

During most daily activities,the human respiration rate is most closely linked to the blood levels of

A)nitrogen.
B)oxygen.
C)carbon dioxide.
D)sodium.

Question 57

Atmospheric pressure at sea level is equal to a column of 760 mm Hg.Oxygen makes up 21% of the atmosphere by volume.The partial pressure of oxygen in such conditions is

A)160 mm Hg.
B)16 mm Hg.
C)1)6 mm Hg.
D)760 mm Hg.

Question 58

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it

A)coats their lungs.
B)blocks the openings into the tracheal system.
C)interferes with gas exchange across the capillaries.
D)clogs their bronchi.

Question 59

Damage to which brain structures will most likely cause impairment of a mammal's breathing cycle?

A)the cerebrum and cerebellum
B)the medulla oblongata and the pons
C)the adrenal medulla and the adrenal cortex
D)the thalamus and the hypothalamus
E)the frontal lobe and the temporal lobe

Question 60

Air rushes into the lungs of humans during inhalation because

A)the rib muscles and diaphragm contract,increasing the lung volume.
B)the volume of the alveoli increases as smooth muscles contract.
C)gas flows from a region of lower pressure to a region of higher pressure.
D)pulmonary muscles contract and pull on the outer surface of the lungs.
E)a positive respiratory pressure is created when the diaphragm relaxes.

Question 61

George is a 67-year-old male who was recently diagnosed with emphysema,a condition that causes shortness of breath due to damaged alveoli.George's physician measured his breathing ability and found that he was able to exhale less air than a healthy male should be able to.What is George's residual volume compared to a healthy male?

A)George's residual volume will be lower compared to a healthy male.
B)George's residual volume will be higher compared to a healthy male.
C)George's residual volume will be the same as compared to a healthy male.

Question 62

Valerie is a 55-year-old female who received an electrocardiogram (ECG)as part of a routine medical examination.She had the ECG performed both at rest and after running on a treadmill for 5 minutes.How would the ECG graphs differ between these two measurements?

A)The peaks on the resting ECG graph would be closer together than the peaks on the exercise ECG graph because her heart rate is higher at rest.
B)The peaks on the exercise ECG graph would be closer together than the peaks on the resting ECG graph because her heart rate is higher during exercise.
C)The peaks on the resting ECG graph would be closer together than the peaks on the exercise ECG graph because her stroke volume is higher at rest.
D)The peaks on the resting ECG graph would be closer together than the peaks on the exercise ECG graph because her stroke volume is higher during exercise.

Question 63

Hydrogen ions (protons)produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to

A)hemoglobin.
B)plasma proteins.
C)carbon dioxide.
D)carbonic acid.

Question 64

An increase in blood plasma pH from 7.3 to 7.4 will cause

A)hemoglobin to release all bound oxygen molecules.
B)an increase in the affinity of hemoglobin to bind oxygen molecules.
C)an increase in the binding of H⁺ by hemoglobin.
D)hemoglobin to more readily give up its oxygen molecules.

Question 65

At what point in the following figure would blood pressure be highest?

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

Question 66

In an animal species known for endurance running rather than fast sprinting,you would expect to find a

A)slower rate of oxygen consumption so that its breathing will not have to be accelerated.
B)decrease in myoglobin concentration in the muscles.
C)relatively slow heart rate in order to lower oxygen consumption.
D)lower pressure of oxygen in the alveoli.
E)much higher rate of oxygen consumption for its size.

Question 67

Hemoglobin and hemocyanin

A)are both found within blood cells.
B)are both red in color.
C)are both freely dissolved in the plasma.
D)both transport oxygen.
E)are both found in mammals.

Question 68

An "internal reservoir" of oxygen in rested muscle is found in oxygen molecules bound to

A)hemoglobin.
B)bicarbonate ion.
C)carbonic acid.
D)myoglobin.

Question 69

A group of students were investigating the effects of smoking on grass frogs for a research paper.They hypothesized that keeping the frogs in a smoke-filled environment for defined periods of time would result in the animals developing lung cancer.However,when they searched for previously published information to support their hypothesis,they discovered they were wrong in their original assessment.What potential harmful effects could carcinogens from tobacco smoke likely have on the frogs,if not lung cancer?

A)the amphibian equivalent of hypertension
B)skin cancer
C)gill abnormalities in the next generation of tadpoles
D)tracheal tube abnormalities

Question 70

Most of the carbon dioxide produced by humans is

A)converted to bicarbonate ions by an enzyme in red blood cells.
B)bound to hemoglobin.
C)transported in the erythrocytes as carbonic acid.
D)simply dissolved in the plasma.

Question 71

Mitral valve prolapse is a condition where the mitral valve (the left atrioventricular valve)does not close fully and thus allows blood to flow "backward," which may be minor or severe depending on the extent of the condition.Into what structure would blood flow immediately "backward" in a person with mitral valve prolapse?

A)left atrium
B)left ventricle
C)aorta
D)pulmonary artery

Question 72

The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in

A)the partial pressure of oxygen.
B)the partial pressure of carbon dioxide.
C)hemoglobin concentration.
D)temperature.
E)pH.

Question 73

Lisa is a healthy 21-year-old female with normal cardiovascular and respiratory function.Assuming she has a normal tidal volume and vital capacity,how much air is left in her lungs after a normal exhalation?

A)0)5 L
B)1)2 L
C)2)9 L
D)3)4 L

Question 74

A biologist discovers the carcass of an animal that was recently partially eaten by a predator in the jungle.The animal's heart was large,well-formed,and had four chambers,with no connection between the right and left sides.A reasonable conclusion supported by these observations is that the

A)animal had evolved from birds.
B)animal was endothermic and had a high metabolic rate.
C)animal was most closely related to alligators and crocodiles.
D)animal was likely an invertebrate animal.
E)species had little to no need to regulate blood pressure.

Question 75

In which of the following animals would you expect to find high concentrations of myoglobin?

A)lizard
B)frog
C)lion
D)seal

Question 76

The hemocyanin of arthropods and molluscs differs from the hemoglobin of mammals in that

A)the oxygen dissociation curve for hemocyanin is linear.
B)hemocyanin carries more carbon dioxide.
C)hemocyanin is bound to copper rather than iron.
D)the protein of hemocyanin is not bound to metals.
E)hemocyanin is bound to potassium ions.

Question 77

If a vial of blood if spun at high speeds in a centrifuge,it separates into three layers: erythrocytes,leukocytes and platelets,and plasma.Which component of blood is the least dense?

A)erythrocytes
B)leukocytes and platelets
C)plasma

Question 78

The longest time a human has been recorded holding their breath is over 22 minutes! When you hold your breath,what happens to your blood chemistry?

A)The CO₂ concentration increases,the hydrogen ion concentration increases,and the pH decreases.
B)The CO₂ concentration increases,the hydrogen ion concentration decreases,and the pH increases.
C)The CO₂ concentration decreases,the hydrogen ion concentration increases,and the pH decreases.
D)The CO₂ concentration decreases,the hydrogen ion concentration decreases,and the pH increases.

Question 79

To become bound to hemoglobin for transport in a mammal,atmospheric molecules of oxygen must cross

A)zero membranes-oxygen binds directly to hemoglobin,a protein dissolved in the plasma of the blood.
B)one membrane-that of the lining in the lungs-and then bind directly to hemoglobin,a protein dissolved in the plasma of the blood.
C)two membranes-in and out of the cell lining the lung-and then bind directly to hemoglobin,a protein dissolved in the plasma of the blood.
D)four membranes-in and out of the cell lining the lung and in and out of the endothelial cell lining an alveolar capillary-and then bind directly to hemoglobin,a protein dissolved in the plasma of the blood.
E)five membranes-in and out of the cell lining the lung,in and out of the endothelial cell lining an alveolar capillary,and into the red blood cell-to bind with hemoglobin.

Question 80

Atmospheric pressure at sea level is equal 760 mm Hg.Denver,Colorado,is at an elevation of 5,280 feet above sea level,and so the atmospheric pressure in Denver is ~623 mmHg.Oxygen is found in the same percentage at both sea level and in Denver.What is the partial pressure of oxygen in Denver compared to at sea level?

A)The partial pressure of oxygen is higher in Denver than at sea level.
B)The partial pressure of oxygen is lower in Denver than at sea level.
C)The partial pressure of oxygen is the same in Denver as at sea level.