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Exercise Physiology > Pulmonary > Flashcards

Pulmonary Flashcards

1
Q

the ventilatory system is subdivided into zones of ventilation

A

conducting zones

transitional and respiratory zones

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2
Q

what is the conducting zones

A

trachea and terminal bronchioles

considered anatomic dead space

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3
Q

functions of the conducting zone

A

air transport humidification warming particle filtration vocalization immunoglobulin secretion

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4
Q

what is the transitional respiratory zones

A

bronchioles alveolar ducts and alveoli

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5
Q

functions of the transitional and respiratory zones

A

gas exchange surfactant production molecule activation and inactivation blood clotting regulation and endocrine function

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6
Q

more then ____ million alveoli provide the surface for gas exchange between lung tissue and blood

A

600

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7
Q

characteristics of the alveoli

A

elastic
thin walled
surface for gas exhcnage
pore of kohn - surfactant

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8
Q

what is surfactant

A

resistance to expansion of the ling cavity and alveoli increases during inspiration from the effect of surface tension

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9
Q

surfactant consists of a ____

A

lipoprotein mixture of phospholipids proteins and calcium ions produced by alveolar epithelial cells that reduces surface tension, this reduces the energy required for alveolar inflation and deflation

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10
Q

ficks law of diffusion states

A

that the rate of transfer of a gas through a tissue is directly proportional to the partial pressure differential between the two sides tissue surface area a diffusion constant and inversely proportional to the tissue thickness

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11
Q

volume of gas diffused is proportional to

A

partial pressure
surface area
diffusion constant

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12
Q

volume of gas diffused is inversely proportional to

A

the thickness of the tissue through which the gas is moving

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13
Q

what are static lung volumes

A 
tidal volume 
inspiratory reserve volume 
expiratory reserve volume
total lung capacity 
residual lung volume 
forced vital capacity 
inspiratory capacity 
functional residual capacity
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14
Q

total lung capacity =

A

RLV + FVC

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15
Q

phases of inspiration

A

diaphragm contracts, flattens, and moves downward toward the abdominal cavity

elongation and enlargement of the chest cavity expands the air in the lungs causing its intrapulmonic pressure to decrease to slightly below atmospheric pressure

lungs inflate as the nose and mouth suck air inward

finishes when thoracic cavity expansion ceases, causing equality between intrapulmonic and ambient atmospheric pressure

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16
Q

during exercise the scaleni and external intercostal muscles between the ribs contract causing

A

the ribs to rotate and lift up and away from the body

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17
Q

inspiratory action _____ during exercise when the diaphragm ____ the ribs swing upward and the sternum thrusts outward

A

increases

descends

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18
Q

athletes often bend forward at the waist to facilitate breathing following exercise because

A

promotes blood flow back to the heart

minimizes antagonistic effects of gravity on the usual upward direction of inspiratory movements

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19
Q

during rest and light exercise represents a passive process of air movement out of the lungs resulting from

A

natural recoil of the stretched lung tissue and relaxation of the inspiratory muscles

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20
Q

what are the phases of expiration

A

sternum and ribs drop diaphragm rises decreasing chest cavity volume and compressing alveolar gas so air moves from respiratory tract to atmosphere

ends when the compressive force of expiratory muscles ceases and intrapulmonic pressure decreases to atmospheric pressure

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21
Q

diring exercise internal intercostal and abdominal muscles act powerfully on the ribs and abdominal cavity to

A

reduce thoracic dimensions

by reducing the dimensions exhalation becomes more rapid and extensive

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22
Q

what is tidal volume

A

air moved during inspiratory or expiratory phase of each breathing cycle 0.4-1L of air per breath

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23
Q

what is inspiratory reserve volume

A

inspiring as deeply as possible following a normal inspiration 2.5-3.5L above inspired tidal air

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24
Q

what is expiratory reserve volume

A

after a normal exhalation continuing to exhale and forcing as much as a possible from the lung 1-1.5L

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25
Q

what is forced vital capacity

A

total volume of air voluntarily moved in one breath includes TV plus IRV and ERV

4-5L in young men and 3-4 L in young women

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26
Q

what is residual lung volume

A

air volume in the lungs after exhaling as deeply as possible

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27
Q

what is the average for residual lung volume

A

0.8-1.2L for collage aged women 0.9-1.4L for collage aged men and increases with age

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28
Q

what does the residual lung volume allow

A

an uninterrupted exchange of gas between the blood and alveoli to prevent fluctuations in blood gases during phases of the breathing cycle

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29
Q

RLV plus FVC constitutes ___

A

total lung capacity

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30
Q

effects of previous exercise on RLV

A

RLV temporarily increases from an acute bout of either short term or prolonged exercise due to

closure of the small peripheral airways

increase in thoracic blood volume

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31
Q

dynamic ventilation depends on

A

maximum stroke volume of the lungs (FVC)

speed of moving a volume of air (breathing rate)

determined by lung compliance or the resistance of the respiratory passages to air and the stiffness imposed by the chest and lung

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32
Q

FEV1.0/FVC indicates

A

pulmonary airflow capacity

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33
Q

healthy people average __ of FVC in 1 second

A

85%

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34
Q

obstructive diseases result in significantly lower

A

FEV1

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35
Q

restrictive diseases result in normal or above normal ___ but the volume of air moved is reduced

A

FEV1

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36
Q

two ways to view pulmonary ventilation

A

volume of air moved into or out of total respiratory tract each minute = minute ventilation

air volume that ventilates only alveolar chambers each minute = alveolar ventilation

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37
Q

what is minute ventilation

A

volume of air breathed each minute (VE)

= tidal volume x breath rate
= o.5L x 12 breaths/min
= 6Lmin

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38
Q

what is alveolar ventilation

A

remember that anatomic dead space averages 150-200mL

therefore only about 350-300mL of the 500mL TV enters alveoli

anatomic dead space increases

despite the increase in dead space, increases in TV result in more effective alveolar ventilation

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39
Q

dead space ___ with tidal volume ( to a less degree)

A

increases

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40
Q

hyperventilation

A

an increase in pulmonary ventilation that exceeds O2 needs of metabolism

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41
Q

hyperventilation ___ PCO2 and H

A

decreases

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42
Q

dyspnea

A

subjective distress in breathing

during exercise respiratory muscles may fatigue, resulting in shallow, ineffective breathing and increased dyspnea

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43
Q

volume of gas diffused is proportional to

ficks law

A

partial pressure
surface area
diffusion constant

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44
Q

volume of gas diffused is ____ to the thickness of the tissue through which the gas is moving

A

inversely proportional

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45
Q

bodys supply of oxygen depends on

A

concentration of ambient air

pressure of ambient air

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46
Q

what is the concentration of ambient air

A
  1. 93% O2
  2. 04% N2
  3. 03% CO2
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47
Q

what is torr

A

the pressure of air molecules that raises a column of mercury in a barometer to a height of 760mm

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48
Q

1 torr equals the pressure necessary to raise

A

a 1mm column of mercury 1mm high at 0 degrees celcius against the standard acceleration of gravity at 45 degrees north latitude

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49
Q

the molecules of each specific gas in a mixture of gases exert

A

their own partial pressure

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50
Q

partial pressure computes as follows

A

partial pressure = percentage concentration of specific gas / total pressure of gas mixture

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51
Q

partial pressures of gases in dry ambient air at sea level

A

PO2 = 159mm Hg

PCO2 = 0.2mm Hg

PN2 = 600mm Hg

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52
Q

partial pressure =

A

% of [gas] x total pressure of mixture

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53
Q

symbols for gas pressure

A 
P = PARTIAL PRESSURE 
S = SATURATION 
A = ALVEOLAR 
a = arterial blood
v = mixed venous blood
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54
Q

o2 and co2 in the environmental inspired air

A

o2 = 159

co2 = 0.2-0.3

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55
Q

air in the trachea becomes saturated air with humidity what are the o2 and co2 values

A 
o2 = 149
co2 = 0.3
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56
Q

alveolar air is diluted with carbon dioxide coming out of the blood
PAO2 and PACO2 values

A 
PAO2 = 100
PACO2 = 40
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57
Q

what is the o2 and co2 in venous blood

A 
PVO2 = 40
PVCO2 = 46
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58
Q

what is the o2 and co2 in arterial blood

A 
PaO2 = 100
PaCO2 = 40
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59
Q

what is the o2 and co2 in contracting muscle

A 
PO2 = 40
PCO2 = 46
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60
Q

at rest blood tends to move through the capillaries in ___ seconds. at max exercise that transient time is as short as ___ seconds, even so that is sufficient time for the blood to become fully saturated in a healthy lung with large alveolar area

A
  1. 75 seconds

0. 40 seconds

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61
Q

what is henrys law

A

the mass of a gas that dissolves in a fluid at a given temperature varies in direct proportion to the pressure of the gas over the liquid

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62
Q

what factors in henrys law govern the rate of gas diffusion into a fluid

A

the pressure differential between the gas above the fluid and the gas dissolved in the fluid

the solubility of the gas in the fluid

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63
Q

o2 travels from a __ to ___ pressure as it dissolves and diffuses through the alveolar membranes into the blood

A

higher to lower pressure

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64
Q

co2 exists under a slightly greater pressure in returning venous blood then in the ____ causing net diffusion of co2 from the ___ into the ____

A

alveoli

blood into the lungs

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65
Q

N2 ___ in alveolar-capillary gas

A

remains essentially unchanged

66
Q

alveolar gas-blood gas equilibrium takes place in ___seconds

A

1/4

67
Q

factors that impair gas transfer capacity at the alveolar capillary membrane

A

buildup of a pollutant layer that thickens the alveolar membrane

reduction in alveolar surface area

each factor extends the time before alveolar-capillary gas equilibrates

68
Q

for individuals with impaired lung function the added demand for rapid gas exchange in exercise compromises

A

aeration

negatively affecting exercise performance

69
Q

the blood carriers oxygen in two ways

A

in physical solution dissolved in the fluid portion of blood

in loose combination with hemoglobin the iron-protein molecule within the red blood cell

70
Q

oxygens relative insolubility in water keeps its

A

concentration low within bodily fluids

71
Q

functions of oxygen transported in solution

A

establishes the po2 of the plasma and tissue fluids

helps to regulate breathing

determines oxygen loading of hemoglobin in the lungs and subsequent release in tissues

72
Q

hemoglobin is

A

the iron containing globular protein pigment

73
Q

hemoglobin carries ___ times more oxygen than normally dissolves in plasma

A

65-70

74
Q

each of the four iron atoms in the hemoglobin molecule can

A

loosely bind one oxygen molecule

Hb4+4O2Hb4O8

75
Q

the partial pressure of oxygen dissolved in physical solution dictates the

A

oxygenation of hemoglobin to oxyhemoglobin

76
Q

what is the oxygen carrying capacity of hemoglobin in men and women

A

15g/dL of blood for men

14g/dL of blood for women

77
Q

the sex difference in oxygen carrying capacity of hemoglobin explains

A

the lower aerobic capacity of women relative to men

mens higher hemoglobin concentrations relate to the stimulating effects on red blood cell production of testosterone

78
Q

each gram of hemoglobin combines loosely with ___mL of oxygen

A

1.34

79
Q

with full oxygen saturation and with normal hemoglobin levels hemoglobin carriers ____mL of oxygen in each dL of whole blood

A

20

80
Q

what is anemias affect on oxygen transport

A

the bloods oxygen transport capacity changes only slightly with normal variations in hemoglobin content

iron deficiency anemia causes a significant decrease in the iron content of red blood cells reduces the bloods oxygen carrying capacity which diminishes a persons capacity to sustain even mild-intensity aerobic exercise

81
Q

what is cooperative binding

A

the binding of an O2 molecule to the iron atom in one of the four globin chains progressively facilitates the binding of subsequent molecules

82
Q

what is the term affinity mean

A

is used to describe oxygens attraction to hemoglobin binding sites

affinity of Hb can be shifted by changes in 
- pH
- temperature 
- CO2
2,3-DPG
83
Q

what does the flat portion of the curve allow for in the oxyhemoglobin dissociation curve. what about the steep portion of the curve

A

safety
diffusion gradient

unloading

84
Q

what is the bohr effect

A

in presence of CO2 the O2 affinity for dissociation of hemoglobin decreases

increase CO2
decreased pH

85
Q

affinity increases with __ temperature
and
affinity decreases with __ temperature

A

decreasing

increasing

86
Q

there is an increased 2,3-DPG shifts curve to the right usually in conjunction with

A

changes in pH CO2 and temperature

87
Q

barometric pressure ___ with altitude

A

decreases

88
Q

a red blood cell derives its energy solely from

A

the anaerobic reactions of glycolysis because they contain no mitochondria causing them to produce the compond 2,3-DPG

89
Q

2,3DPG binds loosely with subunits of the hemoglobin molecule which

A

reduces its affinity for oxygen causing greater oxygen release to the tissues for a given decrease in po2

90
Q

increased levels of red blood cell 2,3DPG occur in those with __disorders and those who live

A

cardiopulmonary

live at high altitudes to facilitate oxygen release to the cells

91
Q

during strenuous exercise 2,3DPG aids in

A

oxygen transfer to muscles

92
Q

myoglobin has a __x higher affinity for o2 than does hemoglobin

A

240

93
Q

myoglobin is

A

an iron containing globular protein in skeletal and cardiac muscle fibers. it resembles hemoglobin because it also combines reversibly with oxygen, but each myoglobin molecule contains one iron atom while hemoglobin contains four iron atoms

94
Q

compared with the oxygen saturation curve for hemoglobin, the curve for myoglobin shows

A

that it much more readily binds and retains oxygen at low po2, the greatest quantity of oxygen releases from MbO2 when tissue PO2 declines below 5mm Hg.

95
Q

acidity carbon dioxide and temperature do/do not affect myoglobins oxygen binding affinity

A

do not affect

96
Q

ventilation of carbon dioxide: once carbon dioxide forms in the cell, ___ and ____ in the venous blood provides the only means for its escape through the lungs

A

diffusion

subsequent transport

97
Q

the blood carries carbon dioxide in three ways

A

in physical solution in plasma (5%)
combined with hemoglobin within the red blood cell (20%)
as plasma bicarbonate (60-80%)

98
Q

how is carbon dioxide carried in physical solution

A

5% of the co2 formed during energy metabolism moves into physical solution in the plasma as free carbon dioxide

the random movement of this small quantity of dissolved carbon dioxide molecules establishes the PCO2 of the blood

99
Q

CO2 transport as carbamino compounds

A

at the tissue level, carbamino compounds form when carbon dioxide reacts directly with the amino acid molecules of blood proteins

the globin portion of hemoglobin which carriers about 20% of the bodys carbon dioxide forms a carbamino compound

100
Q

what is the Haldane effect

A

a decrease in the plasma PCO2 in the lungs reverses carbamino formation causing carbon dioxide to move into solution and enter the alveoli as oxygenation of hemoglobin reduces its ability to bind carbon dioxide

101
Q

carbon dioxide transport as bicarbonate

A

carbon dioxide in solution slowly combines with water to form carbonic acid

once carbonic acid forms in the tissues most of it ionizes into hydrogen ions and bicarbonate ions

60-80% of the total carbon dioxide exists as plasma bicarbonate

102
Q

what is the plasma bicarbonate reaction and what is it facilitated by

A

co2+ h2oh2co3h+hco

facilitated by carbonic anhydrase

103
Q

what are the three basic elements of respiratory control

A

sensors = chemoreceptors, lungs and other send input to the

central controller = pons medulla and other parts that sends output to

effectors = respiratory muscles

104
Q

complex mechanisms adjust breathing rate and depth to the body metabolic needs….

A

intricate neural circuits relay information from higher brain centers lungs and other sensors throughout the body to coordinate ventilatory control

the gaseous and chemical states of the blood that bathes the medulla and aortic and carotid artery chemoreceptors also mediate alveolar ventilation

105
Q

the control mechanisms of pulmonary ventilation maintain

A

relatively constant alveolar gas pressures throughout a broad range of exercise intensities

106
Q

what are the three controls of breathing

A

central controller - ventral lateral medulla and pons
intrinsic pacemaker neurons, network for pattern gen

efferent motor output
- cranial and spinal nerve innervation of upper airway bronchial smooth muscle and respiratory pump muscles

sensory
- medullary and carotid chemoreceptors
mechanoreceptors

107
Q

normal breathing controlled by circuits in the

A

pons and medullar (pontomedullary circuit)

108
Q

ventral lateral medulla has pacemaker neurons linked to a pattern generator,ablation of this area or the rostral pons

A

disrupts normal breathing

both areas are required

109
Q

rhythm generation from pontomedullary neuronal circuit is directed to the

A

phrenic intercostal and abdominal motor nerves

110
Q

efferent motor output well patterned output during normal breath expiration is ___ and inhalation is governed

A

passive

by diaphragm (phrenic n) external intercostals (intercostal n)

111
Q

peripheral sensory input

A

chemoreceptor

  • peripheral chemoreceptors
  • medullary receptors
    highly pH sensitive esp due to co2
    responds to PaCO2 strongly in steady state
  • negative feedback
112
Q

Co2 influences ___ to a large extent

A

minute ventilation

113
Q

sensitivity to reduced oxygen pressure resides in the ____

A

peripheral chemoreceptors

114
Q

the carotid bodies monitors the state of ____ just before it perfuses the ____

A

arterial blood

brain

115
Q

decreased arterial PO2 ___ alveolar ventilation through aortic and carotid chemoreceptor stimulation

A

increases

these receptors alone protect the organism against reduced oxygen pressure in inspired air

116
Q

peripheral chemoreceptors also stimulate ventilation in exercise because of

A

increases in temperature acidity and carbon dioxide sand potassium concentrations

117
Q

at rest carbon dioxide pressure in arterial plasma provides the most

A

important respiratory stimulus

118
Q

small increases in PCO2 in inspired air trigger

A

large increases in minute ventilation

119
Q

plasma acidity which varies with the bloods carbon dioxide content exerts

A

command over minute ventilation

120
Q

a fall in blood pH signals acidosis and reflects

A

carbon dioxide retention and carbonic acid formation

121
Q

as arterial pH declines and hydrogen ions accumulate inspiratory activity

A

increases to eliminate carbon dioxide and reduce arterial levels of carbonic acid

122
Q

if a person breath holds after a normal exhalation it takes about ___seconds for the urge to breath cause inspiration

A

40 seconds

123
Q

the stimulus to breath when holding your breath comes primarily from

A

increased arterial pco2 and h concentration

124
Q

the breakpoint for breath holding =

A

50mm Hg PCO2

125
Q

hyperventilation before breath holding causes

A

alveolar PCO2 to decrease to 15 mmHg

a larger than normal quantity of carbon dioxide leaves the blood and arterial PCO2 decreases

extends breath holding duration until arterial PCO2 and/or H concentration cause the urge to breath

126
Q

mechanical sensoty afferent feedback provided by vagus n. limits

A

end-inspiratory lung volume

responses as a stimulus during lung deflation

stretch receptors

127
Q

respiratory muscle feedback relayed by

A

group 3 mechanical

group 4 chemical

128
Q

what are the 4 regulation of breathing during exercise

A

chemical control
- no single chemical mechanism responsible for hypernea during exercise

neurogenic factors

  • cortical influence
  • peripheral influence

temperature has little influence on respiratory rate during exercise

humoral factors
- chemical state of blood

129
Q

combined and simultaneous effects pf several chemical and neural stimuli initiate and modulate

A

exercise alveolar ventilation

130
Q

ventilation phases during exercise and recovery :

A

phase 1 = neurogenic stimuli from cerebral cortex and feedback from active limbs stimulate the medulla to abruptly increase ventilation

phase 2 = after a brief plateau ventilation rises exponentially to achieve a steady rate related to metabolic gas exchange demands

phase 3 = fine tuning of steady rate ventilation through peripheral sensory feedback mechanisms

131
Q

ventilation in steady rate exercise during light to moderate exercise

A

increases linearly with O2 consumption and co2 production

132
Q

non steady rate ventilation in exercise

A

VE rises sharply and the ventilatory equivalent rises as high as 35-40L of air per liter of oxygen

ventilatory threshold
lactate threshold
onset of blood lactate accumulation

133
Q

the point of ventilatory threshold occurs at a work rate when ___
the lactate threshold occurs at this point however blood lactate remains

A

VE and VO2 deviate from being linear

low at this point as it is only starting to accumulate

134
Q

lactate threshold describes the ____

A

highest oxygen consumption or exercise intensity achieved with less than a 1 mm increase in blood lactate concentration above the pre exercise level

135
Q

the onset of blood lactate accumulation is defined as the

A

exercise intensity when blood lactate levels exceed 4mm

this event technically occurs after the lactate threshold has passed because it takes some time for the lactate to accumulate to a level high enough to detect in a blood test

136
Q

lactate accumulation reflects changes in

A

pH
bicarbonate and H concentrations
co2 production via buffering

together can provide indirect assessment

137
Q

the measurement of lactate threshold serves three important functions

A

provides a sensitive indicator of aerobic training status

predicts endurance performance often with greater accuracy then VO2max

establishes an effective training intensity geared to active muscles aerobic metabolic dynamics

138
Q

what are three different indicators of lactate threshold

A

fixed blood lactate concentration

ventilatory threshold

blood lactate exercise v02 response

139
Q

major variables contributing to oxygen transport and use, vo2 max is traditionally used to predict

A

performance but OBLA may also be an excellent tool

140
Q

increased H concentration from carbon dioxide production and lactate formation during strenuous exercise makes

A

pH regulation progressively more difficult

141
Q

acid based regulation becomes exceedingly difficult during repeated brief bouts of all out exercise that

A

elevate blood lactate values to 30 mm or higher

142
Q

humans temporarily tolerate pronounced disturbances in

A

acid base balance during maximal exercise

143
Q

a plasma pH below 7 can cause

A

nausea headache and dizziness

144
Q

the chemical buffering system consists of

A

a weak acid and salt of that acid

145
Q

when H concentration remains elevated the reaction __ in contrast when H concentration the buffering reaction moves

A

produces the weak acid

in the opposite direction and releases H

146
Q

chemical buffers that provide the first line of defense

second line of defense; when does this buffering function occur

A

bicarbonate buffers

phosphate buffers

protein buffers

secondary = pulmonary and renal systems
occurs when a change in pH has already occurred

147
Q

what is the ventilatory buffer

A

when H in extracellular fluid and plasma increases it stimulates the respiratory center to increase alveolar ventilation which reduces alveolar co2 and causes co2 to be blown off which reduced plasma co2 levels accelerate the recombination of H and HCO lowering H concentration in plasma

148
Q

what is renal buffer

A

renal tubules regulate acidity through complex chemical reactions that secrete ammonia and H into urine and reabsorb alkali chloride and bicarbonate

149
Q

does ventilation limit aerobic power and endurance

A

healthy individuals overbreathe at higher levels of o2 consumption

at max exercise there usually is a breathing reserve

ventilation in healthy individuals is not the limiting factor in exercise

little relationship exists among diverse lung volumes and capacities and exercise performance

150
Q

aerobic training produces considerably less adaption in

A

pulmonary structure and function then in cardiovascular and neuromuscular adaptations

151
Q

during strenuous exercise healthy individuals

A

overbreath at higher levels of oxygen consumption

this hyperventilation response decreases alveolar pco2 and slightly increases alveolar po2

152
Q

during max exercise a breathing reserve exists because

A

VE at vo2max is only 60-85% of a healthy persons MVV

153
Q

pulmonary function does not form a weak link in the

A

oxygen transport system of healthy individuals with average to moderately large aerobic capacities

154
Q

the oxygen requirement of breathing remains ___ at rest and during ligh to moderate exercise

A

relatively small at rest and during light to moderate exercise

155
Q

for exercise ventilations up to about 100L min oxygen cost averages ___per liter of air breathed each minute or __% of the total oxygen consumption in moderate exercise and 8-11% for minute ventilations at vo2max

A

1.5-2mL

3-5%

156
Q

for highly trained endurance athletes with minute ventilations of 150L min and higher the cost of exercise hyperpnea can be

A

> 15% of total oxygen consumption

157
Q

in chronic obstructive pulmonary disease the added expiratory resistance can

A

triple the normal cost of breathing at rest

158
Q

in severe pulmonary disease the cost of breathing attains __% of the total exercise oxygen consumption

A

40%

159
Q

competition between the oxygen blood flow needs of locomotor and respiratory muscles encroaches on the

A

oxygen available to the active non-respiratory muscles

160
Q

for endurance athletes the pulmonary system…

A

lags behind the cardiovascular and aerobic muscular adaptations

161
Q

exercise induced arterial hypoxemia is

A

an impaired ventilation, perfusion during high intensity exercise may compromise arterial saturation and oxygen transport

162
Q

possible causes for arterial desaturation include

A

inequality in ventilation - perfusion within the lungs

shunting of blood between venous and arterial circulations
failure to achieve end capillary equilibrium

Exercise Physiology (13 decks)

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