Chapter 10 Respiration Exercise Physiology

Front 1

Cellular respiration refers to
a. the exchange of gases at the lungs.
b. oxygen utilization and carbon dioxide production at the tissues.
c. pulmonary respiration
d. the ability of the alveoli to exchange gases in the lungs

Back 1

b. oxygen utilization and carbon dioxide production at the tissues

Front 2

During exercise, the respiratory system plays a role in acid-base balance by
a. removing H+ from the blood by the HCO3- reaction.
b. aiding the kidney in the removal of lactic acid.
c. lowering the pH of the blood by hyperventilating.
d. increasing the pH of the blood by hyperventilating.

Back 2

a. removal H+ from the blood by the HCO3- reaction.

Front 3

The conducting zone of the respiratory system
a. serves as a passageway for air.
b. has alveoli which allow for gas exchange to occur.
c. functions to humidify and filter the air.
d. does both A and C.

Back 3

d. does both A and C.

Front 4

Expiration occurs when the pressure within the lungs exceeds atmospheric pressure and
a. involves the relaxation of the diaphragm.
b. is passive during normal, quiet breathing
c. requires contraction of the diaphragm only during exercise or voluntary hyperventilization.
d. all of the above.

Back 4

d. all of the above.

Front 5

At the onset of exercise, the primary drive to increase pulmonary ventilation is due to
a. the activity of higher brain centers
b. feedback from peripheral chemoreceptors
c. feedback from central chemoreceptors
d. all of the above

Back 5

a. activity of higher brain centers

Front 6

The region of the lung that receives the greatest percentage of the total ventilation is the
a. apical region
b. basal region
c. both the apical and the basal region receive the same percentage of the ventilation

Back 6

b. basal region

Front 7

Fick's law of diffusion states that the rate of gas transfer is proportional to
a. the tissue area for diffusion and the difference in the partial pressure of the gas on the two sides of the tissue
b. the tissue thickness and the tissue area for diffusion
c. the tissue area for diffusion, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue
d. none of the above

Back 7

a. the tissue area for diffusion and the difference in the partial pressure of the gas on the two sides of the tissue.

Front 8

The partial pressure of oxygen is
a. higher in the alveoli than in the pulmonary artery
b. higher in the pulmonar artery than the systemic arteries
c. higher in the systemic arteries than the alveoli
d. higher in the systemic veins than the arteries

Back 8

a. higher in the alveoli than the pulmonary artery

Front 9

The partial pressure of carbon dioxide is
a. higher in the alveoli than the pulmonary artery
b. higher in the pulmonary artery than the systemic arteries
c. higher in the alveoli than the systemic arteries.
d. higher in the systemic arteries than the veins

Back 9

b. higher in the pulmonary artery than the systemic arteries

Front 10

A V/Q relationship greater than 1.0 represents
a. a greater blood flow than ventilation
b. an ideal condition for gas exchange
c. a greater ventilation than blood flow
d. a higher than normal cardiac output

Back 10

c. a greater ventilation than blood flow

Front 11

During exercise, there is a shift in the oxygen-hemoglobin dissociation curve
a. to the right
b. which allows for greater unloading of oxygen to the tissues
c. which indicates a lower affinity of Hb for O2.
d. all of the above.

Back 11

d. all of the above

Front 12

Removal of CO2 from the blood will decrease hydrogen ion concentration and thus
a. decrease pH
b. increase pH
c. have no effect on pH

Back 12

b. increase pH

Front 13

Ventilation increases as a linear function of oxygen uptake up to a point known as the
a. the PCO2 inflection point.
b. the steady state inflection point
c. the ventilatory threshold
d. both b and c.

Back 13

c. the ventilatory threshold

Front 14

Input into the respiratory control center can be classified in which two ways?
a. pneumotaxic and apneustic
b. aortic and carotid
c. O2 and CO2
d. neural and humoral

Back 14

d. neural and humoral

Front 15

Central chemoreceptors are sensitive to changes in PCO2 and pH in
a. the blood
b. the cerebrospinal fluid
c. the sarcoplasm
d. all of the above

Back 15

b. the cerebrospinal fluid

Front 16

The likely mechanism that explains the alinear rise in ventilation during an incremental exercise test is
a. a circulatory deficiency
b. aortic and carotid bodies are depressed
c. blood hydrogen concentration
d. none of the above

Back 16

c. blood hydrogen concentration

Front 17

During high-intensity exercise, PO2 can drop in some elite athletes. This is due to
a. exceeding the mitochondrial capacity of the muscle
b. exercise-induced brochospasm
c. incomplete oxygenation of blood as a result of a very high cardiac output
d. breath holding

Back 17

c. incomplete oxygenation of blood as a result of a very high cardiac output

Front 18

During submaximal exercise, ventilation is fine-tuned by input from
a. muscle mechanoreceptors
b. central chemoreceptors
c. peripheral chemoreceptors
d. blood hydrogen ion concentration

Back 18

a. muscle mechanoreceptors

Front 19

The initial drive to inspire or expire comes from neurons located in the
a. medulla oblongata
b. cerebral cortex
c. adrenal medulla
d. cerebrum

Back 19

b. cerebral cortex

Front 20

The shift in the O2-Hb dissociation curve during exercise is caused by
a. higher blood temperature
b. higher blood pH
c. hypoxia
d. hypoglycemia

Back 20

a. higher blood temperature

Front 21

How is the majority of the carbon dioxide in the blood transported?
a. bound to hemoglobin
b. dissolved in the plasma
c. as bicarbonate
d. none of the above

Back 21

c. as bicarbonate

Front 22

Diffusion occurs rapidly bcause there is a large surface area within the lungs and a very _____ (short/long) diffusion distance between blood and gas in the lungs.

Back 22

short

Front 23

The human respiratory system consists of a group of passages that filter air and transport it into the lungs, where gas exchange occurs within microscopic air sacs called _______.

Back 23

alveoli

Front 24

The organs of the respiratory system include the nose, nasal cavity, pharynx, larynx, trachea, bronchial tree, and the lungs themselves. What respiratory muscle are the lungs closest to?

Back 24

Diaphragm

Front 25

Both the right and left lungs are enclosed by a set of membranes called _______.

Back 25

pleura

Front 26

The _______ pleura adheres to the outer surface of the lung, whereas the ________ pleura lines the thoracic walls and the diaphragm.

Back 26

visceral
parietal

Front 27

The pressure in the pleural cavity (intrapleural pressure) is _____ (greater/less) than atmospheric and becomes even lower during inspiration, causing air to inflate the lungs.

Back 27

less

Front 28

The ___________ zone contains all the trachea, bronchi, bronchioles, and terminal bronchioles that are passes through.

Back 28

conducting

Front 29

The region of the lung where gas exchange occurs is labeled the ___________ zone and includes the respiratory bronchioles, alveolar ducts, and alveolar sacs.

Back 29

respiratory

Front 30

In general, humans breathe through the nose until ventilation is increased to approximately __ to __ liters per minute, at which time the mouth becomes the primary passageway for air.

Back 30

20-30

Front 31

For gas exchange to enter or leave the trachea, it must pass through a valvelike opening called the ________.

Back 31

epiglottis

Front 32

Fill in the correct order of air entering the lungs: Nose, ______ ______, pharynx, ________, trachea, left and right trachea, bronchiole tree, bronchioles, alveolar ducts, ______

Back 32

nasal cavity
larynx
alveoli

Front 33

The conducting zone of the respiratory system not only serves as a passageway for air, but also functions to ______ and filter air as it moves toward the respiratory zone of the lung.

Back 33

humidify

Front 34

_______ secreted by the cells of the conducting zone, traps small inhealed particle. This ____ Is moved toward the oral cavity via tiny fingerlike projections called cilia.

Back 34

mucus

Front 35

A second means of protecting the lung from foreign particles is by the action of cells called ___________ that reside primarily in the alveoli. These literally engulf particles that reach the alveoli.

Back 35

macrophages

Front 36

Gas exchange in the lung occurs across about ____ alveoli. The rate of diffusion is further assisted by the fact that each alveolus is only one cell layer thick.

Back 36

300

Front 37

Some of the alveolar cells synthesize and release a material called ________ which lowers the surface tension for alveoli and thus prevents their collapse.

Back 37

surfactant

Front 38

Movement of air from the environment to the lungs is called pulmonary ventilation and occurs via a process known as _____ _____. This refers to the movement of molecules along a passageway due to a pressure difference between the two ends of the passageway.

Back 38

bulk flow

Front 39

__________ occurs due to the pressure in the lungs being reduced below atmospheric pressure. _________ occurs when the pressure within the lungs exceeds atmospheric pressure.

Back 39

inspiration
expiration

Front 40

The ________ is the most important muscle of inspiration and is the only skeletal muscle essential for life. What nerves innervate this muscle?

Back 40

diaphragm
phrenic nerves

Front 41

When the diaphragm contracts, it forces the abdominal contents downward and ________ and the ribs are lifted outward.

Back 41

forward

Front 42

This expansion of the lungs results in a _________ in intrapulmonary pressure below atmospheric, which allows airflow into the lungs.

Back 42

reduction

Front 43

During normal, quiet breathing the diaphragm performs most of the work of inspiration. However, during exercise, __________ muscles of inspiration are called into play. These include the external intercostal muscles, pectoralis minor, the scalene muscles and the sternocleidomastoids. Collectively, these muscles assist the diaphragm in increasing the volume of the ______, which aids in inspiration.

Back 43

accessory
thorax

Front 44

True/False There is no muscular effort necessary for expiration to occur at rest.

Back 44

True

Front 45

This is true because the lungs and chest walls are _____ and tend to return to equilibrium position after expanding during inspiration.

Back 45

elastic

Front 46

During exercise and voluntary hyperventilation, expiration becomes active. The most important muscle involved in expiration are those found in the __________ wall, which include the rectus abdominus and the internal oblique. When these muscles contract, the diaphragm is pushed upward and the ribs are pulled downward and inward. This results in an increase in intrapulmonary pressure and expiration occurs

Back 46

abdominal

Front 47

At any given rate of airflow into the lungs, the pressure difference that must be developed depends on the _________ of the airways. Mathematical relationship is
Airflow = (P1-P2)/Resistance

Back 47

resistance

Front 48

Airflow is (decreased/increased) any time there is an increase in the pressure gradient across the pulmonary system, or if there is a decrease in airway resistance.

Back 48

increased

Front 49

The most important variable contributing to airway resistance is the _________ of the airway.

Back 49

diameter

Front 50

Airways that are reduced in size due to disease offer (less/more) resistance to flow than healthy, open airways.

Back 50

more

Front 51

Amount of air inhaled or exhaled in one breath during quiet breathing. Typical value: 500 mL

Back 51

tidal volume

Front 52

Amount of air in excess of tidal volume that can be inhaled with maximum effort. Typical volume: 3,000 mL

Back 52

inhaled reserve volume

Front 53

Amount of air in excess of tidal volume that can be exhaled with maximum effort. Typical volume: 1,200 mL

Back 53

exhaled reserve volume

Front 54

Amount of air remaining in the lungs after maximum expiration; that is, the amount of air that can never be voluntarily exhaled. Typical volume: 1,300 mL

Back 54

residual volume

Front 55

Amount of air that can be forcefully exhaled following a maximum inspiration ___ = (ERV + TV + IRV).
Typical volume: 4,700 mL.

Back 55

Vital Capacity
VC

Front 56

Maximum amount of air that can be inhaled following a normal expiration ___ = (TV + IRV) Typical volume: 3,500 mL.

Back 56

Inspiratory Capacity
IC

Front 57

Maximum amount of air in the lungs at the end of a maximum inspiration ___ = (RV + VC). Typical volume: 6,000 mL

Back 57

Total Lung Capacity
TLC

Front 58

It is important to understand that not all of the air that passes the lips reaches the alveolar gas compartment, where gas exchange occurs. Part of each breath remains in conducting airways and thus does not participate in gas exchange. This "unused" ventilation is called dead-space ventilation and the space it occupies is known as __________ ______ ______.

Back 58

anatomical dead space

Front 59

The volume of inspired gas that reaches the respiratory zone is referred to as _________ __________.

Back 59

alveolar ventilation

Front 60

The amount of gas ventilated per minute is the product of the frequency of breathing and the amount of gas moved per breath (________ ________). V = Vt x f

Back 60

tidal volume

Front 61

The total minute ventilation can be subdivided into dead space ventilation and alveolar ventilation: V =

Back 61

VA + VD

Front 62

The basal region of the lung receives (less/more) ventilation than the apex region, particularly during quiet breathing.

Back 62

more

Front 63

Pulmonary volumes can be measured via a technique known as ________.

Back 63

spirometry

Front 64

Spirometry is useful in diagnosing COPD. COPD patients will have a diminished ______ _____ an a reduced rate of expired airflow during maximal expiratory effort. Further, because of increased airway resistance and airway closure during expiration, COPD patients cannot expire as much gas as healthy individuals, this results in trapped gas in the lungs and an abnormally high residual volume.

Back 64

vital capacity

Front 65

According to Dalton's law, the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert independently, this is known as _____ _________.

Back 65

partial pressures

Front 66

Diffusion of a gas across tissues is described by _____ ____ of ________, which states that the rate of gas transfer (V gas) is proportional to the tissue area, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue, and is inversely proportional to the thickness.

V gas = (A/T) x D x (P1-P2)
A: Area
T: Thickness
D: Diffusion
P1-P2: difference in partial pressure

Back 66

Fick's law of diffusion

Front 67

The amount of oxygen or carbon dioxide dissolved in blood obey's _______ ____ and is dependent on the temperature of blood, the partial pressure of the gas, and the solubility of the gas.

Back 67

Henry's law

Front 68

The pulmonary circulation begins at the pulmonary artery, which receives mixed venous blood from the right ventricle. Mixed venous blood is then circulated through the pulmonary _________ where gas exchange occurs and this oxygenated blood is returned to the left atrium via the pulmonary vein to be circulated throughout the body.

Back 68

capillaries

Front 69

True/False The rate of blood flow throughout the pulmonary circulation is equal to that of the systemic circulation.

Back 69

True

Front 70

True/False The pressures in the pulmonary circulation are relatively HIGH when compared to those in the systemic circulation.

Back 70

False LOW

Front 71

During exercise, blood flow to the apex of the lung is (decreased/increased).

Back 71

increased

Front 72

________ describes the blood flow to the alveolus. If ventilation and perfusion do not match up, normal gas exchange does not occur.

Back 72

Perfusion

Front 73

The ideal ventilation-to-perfusion (V/Q) is ___ or slightly higher. In the apex of the lung the V/Q is 3.4 and in the base of the lung the V/Q is 0.64.

Back 73

1.0

Front 74

Approximately 99% of the oxygen transported in the blood is chemically bound to ________, which is a protein contained in the red blood cells (erythrocytes).

Back 74

hemoglobin

Front 75

Each molecule of hemoglobin can transport four oxygen molecules. The binding of oxygen to hemoglobin forms ___________, hemoglobin that is not bound to oxygen is referred to as _______________.

Back 75

oxyhemoglobin
deoxyhemoglobin

Front 76

Normal hemoglobin concentrations for a healthy male and female are ___ g and ___ g respectively.

Back 76

150
130

Front 77

The combo of oxygen with hemoglobin in the lung (alveolar capillaries) is sometimes referred to as ______ and the release of oxygen from hemoglobin at the tissues is called ________.

Back 77

loading
unloading

Front 78

A high PO2 and Hb-O2 affinity causes oxygen to bind to hemoglobin. The effect of PO2 on the combo of oxygen and hemoglobin can best be illustrated by the oxyhemoglobin dissociation curve. This is a _______ (S-shaped) curve.

Back 78

sigmoidal

Front 79

The strength of the blood between oxygen and hemoglobin is weakened by a decrease in pH (increased _______), which results in an unloading of oxygen to the tissues. This is represented by a right shift in the oxyhemoglobin curve and is called the _____ ______. The mechanism to explain the Bohr effect is the fact that protons bind to hemoglobin, which reduces its oxygen transport capacity. Therefore, when there is a higher-than-normal concentration of H+ in the blood there is a reduced hemoglobin affinity for oxygen.

Back 79

acidity
Bohr effect

Front 80

The affinity of hemoglobin for oxygen is inversely related to blood temperature.That is, a decrease in temperature results in loading, whereas an increase in temperature results in _______.

Back 80

unloading

Front 81

Red blood cells are unique in that they do not contain a nucleus or mitochondria. Therefore, they must rely on anaerobic glycolysis to meet the cell's energy needs. A by-product of RBC glycolysis is the compound 2,3 DPG, which can combine with hemoglobin and (reduce/increase) hemoglobin's affinity for oxygen.

Back 81

reduce

Front 82

_______ is an oxygen-binding protein found in skeletal muscle fibers and cardiac muscle and acts as a shuttle to move oxygen from the muscle cell membrane to the mitochondria.

Back 82

Myoglobin

Front 83

Myoglobin has a _______ affinity for oxygen than hemoglobin.

Back 83

greater

Front 84

Carbon dioxide is transported in the blood in three forms: 1. _______ CO2 (10%)
2. CO2 bound to _________ (20%)
3. __________ (70%)

Back 84

dissolved
hemoglobin
bicarbonate

Front 85

A high PCO2 causes CO2 to combine with H2O, (H2CO3), which is catalyzed by the enzyme carbonic anhydrase. After formation H2CO3 dissociates into a hydrogen ion and a bicarbonate ion. These carbonate ion diffuses out of the RBC into the plasma. There is a _______ ______.

Back 85

chloride shift

Front 86

Removal of CO2 from blood results in a increase in pH. Therefore, pulmonary ________ causes an exhalation of additional CO2 and results in a reduction of blood PCO2 and a lowering of hydrogen ion concentration.

Back 86

ventilation

Front 87

Arterial PO2 _______ and arterial PCO2 ________slightly in the transition from rest to steady-state exercise.

Back 87

decreases
increases

Front 88

Ventilation increases as a ______ function of oxygen uptake up to 50% to 75% of O2 max, where ventilation begins to rise exponentially. This point is known as the __________ __________.

Back 88

linear
ventilatory threshold

Front 89

Some elite athletes developed exercise induced _______, which is a low PO2.

Back 89

hypoxemia

Front 90

Contraction and relaxation of respiratory muscles are directly controlled by _______ _____ neurons in the spinal cord. Motor neuron activity, in turn, is directly controlled by the respiratory control center in the ________ ________.

Back 90

somatic motor
medulla oblongata

Front 91

The stimulus for inspiration comes from four distinct respiratory rhythm centers located within both the medulla oblongata and the pons regions of the brain stem. The rhythm generating centers in the medulla are named the preBotzinger _______ and the __________ nucleus

Back 91

complex
retrotrapezoid

Front 92

The rhythm generating centers in the pons are composed of two clusters of neurons called the pneumotaxic _____ and the caudal ____.

Back 92

center
pons

Front 93

The normal rhythm of breathing occurs due to an interaction between pacemaker neurons in each of these regions. At rest, the breathing rhythm appears to be dominated by pacemaker neurons in the ________ with assistance fro other regulatory regions.

Back 93

preBotC

Front 94

True/False During exercise, the preBotC interacts with other respiratory rhythm centers to regulate breathing to match the metabolic demand.

Back 94

True

Front 95

(Humoral/Neural) input to the respiratory control center refers to the influence of some blood-borne stimuli reaching a specialized chemoreceptor.

Back 95

Humoral

Front 96

(Humoral/Neural) input refers to afferent or efferent input to the respiratory control center from neurons that are excited by means other than blood borne stimuli.

Back 96

Neural

Front 97

Humoral ______ chemoreceptors are located in the medulla and are effected by changes in PCO2 and H+ of the cerebrospinal fluid. An increase in these values results in afferent input to respiratory center to increase ventilation.

Back 97

central

Front 98

Humoral _______ chemoreceptors located in the aorta are called aortic bodies, and those found in the carotid artery are called carotid bodies.

Back 98

peripheral

Front 99

Expiratory ventilation increases as a ______ function of arterial PCO2, which is likely due to peripheral carotid bodies and central chemoreceptors.

Back 99

linear

Front 100

It appears that ventilatory control during exercise has similarities to the control of the cardiovascular system. The increased ventilation during exercise is due to neural input from higher brain centers (_______ command), and both neural and humoral input to the respiratory control center. It seems likely that efferent neural mechanisms from higher brain centers provide the primary drive to breathe during exercise, with humoral chemoreceptors and neural feedback from working muscles providing a means of precisely matching ventilation with the amount of CO2 produced via metabolism.

Back 100

central

Front 101

The rise in blood lactate and reduction in blood pH observed at the lactate threshold can stimulate ventilation and may be a primary mechanism to explain the __________ threshold.

Back 101

ventilatory

Front 102

True/False High intensity exercise can limit can be limited by the pulmonary system.

Back 102

True

Front 103

True/False Exercise induced hypoxemia negatively effects an athletes ability to deliver oxygen to their muscles and can be a limiting factor.

Back 103

True