Respiratory System Flashcards

1
Q

The relaxation and dilation of the upper airways is a function of the ___________ (sympathetic or parasympathetic) branch of the autonomic nervous system, mediated by ___________ (neurotransmitter) binding to ___________ (receptor type) receptors.

A

sympathetic, epinephrine/norepinephrine, adrenergic (β2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

___________ is the medical term for the total rate of air movement into and out of the lungs.

A

ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

___________ law states that the product of pressure and volume is constant, a relationship that helps explain how pressure changes in the lungs drive breathing.

A

Boyle’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

___________ volume refers to the volume of air breathed in and out during a normal breath, while ___________ volume represents the additional volume of air that can be forcibly inhaled after a normal inhalation.

A

Tidal, inspiratory reserve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The majority of gas exchange occurs in the ________.

A

alveolar sacs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Smoking affects the ______ lobes of the lung the most.

A

upper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The ___________ are tiny sacs in the lungs where gas exchange takes place, primarily mediated by ___________ cells.

A

alveoli, Type I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

While Type I alveolar cells are primarily responsible for gas exchange, ___________ cells within the alveoli are crucial for fluid reabsorption and the secretion of ___________, a substance that reduces surface tension and prevents alveolar collapse.

A

Type II, surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False: sympathetic innervation of the airways leads to dilation.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Albuterol acts at _____ receptors.

A

Beta-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True or False: The back of the trachea has collagen rings.

A

False (C-shape allows for both expansion of trachea and protection)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

___________ refers to the total volume of the lung that does not participate in gas exchange, including the anatomical dead space of the conducting airways and any alveolar volume that is not adequately perfused.

A

Physiologic dead space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The conducting zone consists of: ________

A

Trachea, bronchi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

True or False: No gas exchange occurs in the conducting zone.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The forced expiratory volume in 1 second (FEV1) divided by the forced vital capacity (FVC) is approximately ___________ in healthy individuals, and a value below this threshold suggests ___________.

A

0.8, obstructive lung disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Increase the velocity of air may aid in _______.

A

coughing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Bronchioles, unlike the alveoli, primarily engage in fluid ___________ (secretion or reabsorption), driven by the movement of ___________ ions through epithelial cell ___________ channels.

A

secretion, Cl-, CFTR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The aqueous layer on top of the luminal layer of the alveolar cells is very ______.

A

thin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

CFTR stands for _______.

A

Cystic Fibrosis Transmembrane Conductance Regulator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In the context of pulmonary physiology, ___________ refers to the process of air reaching the alveoli, while ___________ refers to the blood flow in pulmonary capillaries that allows for gas exchange.

A

ventilation, perfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The partial pressure of oxygen (PaO2) in arterial blood is typically ___________ (higher or lower) than the partial pressure of oxygen in the alveoli (PAO2).

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

An increase in the physiological dead space will ___________ (increase or decrease) the efficiency of gas exchange in the lungs.

A

decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

During exercise, alveolar ventilation ___________ (increases or decreases) to meet the increased demand for oxygen uptake and carbon dioxide removal.

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The shape of alveolar Type I cells is _______, while Type II is more _______.

A

squamous, cuboidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Normal breathing is referred to as _____.

A

tidal volume (TV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Vital capacity is ______.

A

The summation of IRV and ERV.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

FEV1 is the amount of air able to be _______ in one second.

A

expired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

True or False: residual volume is able to be measured by simple spirometer.

A

False, you can’t get all the air out of your lungs because they will collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Constriction of the bronchioles, as seen in asthma, primarily affects ___________ (airway resistance or lung compliance) and leads to ___________ (increased or decreased) airflow.

A

airway resistance, decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The volume of air remaining in the lungs after a maximal exhalation is called the ___________.

A

residual volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Common way of measuring RV nowadays is _____.

A

helium dilution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Average total ventilation for an adult is _____ ml/min.

A

7500

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Average alveolar ventilation for an adult is ______ ml/min.

A

5250

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Minute ventilation is tidal volume x _________.

A

breaths per minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Inspired air is approximately ______ mmHg.

A

150

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Mixed venous blood has (in terms of partial pressure) approximately ______ mmHg oxygen and ______ mmHg CO2.

A

40, 46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Horseshoe crabs have ______ instead of iron in the middle of hemoglobin.

A

copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The byproduct of RBC glycolysis that affects oxygen dissociation is ________.

A

23DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

The metal ion at the center of the heme group in hemoglobin is ______.

A

Iron (Fe)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The effect that describes the influence of pH and CO2 on oxygen binding to hemoglobin is the __________.

A

Bohr Effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The effect that describes the influence of oxygen on CO2 binding to hemoglobin is the _________.

A

Haldane Effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

The approximate percentage of oxygen transported in the blood that is dissolved in plasma is _______.

A

15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

The protein responsible for the majority of oxygen transport in the blood is __________.

A

hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

One molecule of hemoglobin can bind _____ oxygen molecules.

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

The condition where the iron in hemoglobin is oxidized to Fe3+ and cannot bind oxygen is ____________.

A

Methemoglobinemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

The partial pressure of oxygen PO2 in arterial blood is approximately ________.

A

100 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The partial pressure of oxygen PO2 in mixed venous blood is approximately _________.

A

40 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

The approximate oxygen saturation of arterial blood is _____.

A

98

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The approximate oxygen saturation of mixed venous blood is _____.

A

75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

The graph that shows the relationship between oxygen partial pressure and hemoglobin saturation is the _____________.

A

Oxygenhemoglobin dissociation curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

The shape of the oxygen-hemoglobin dissociation curve is ________.

A

Sigmoidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

A rightward shift of the oxygen-hemoglobin dissociation curve is caused by ___________.

A

Increased temperature, Increased PCO2, Increased 23DPG, Decreased pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

A leftward shift of the oxygen-hemoglobin dissociation curve is caused by ____________.

A

Decreased temperature, Decreased PCO2, Decreased 23DPG, Increased pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

The P50 value is ______________.

A

The partial pressure of oxygen at which hemoglobin is 50 saturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

The effect of increased 23DPG on oxygen affinity of hemoglobin is ____________.

A

Decreased affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Conditions that can lead to increased 23DPG levels are ________.

A

Hypoxia, High altitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Fetal hemoglobin differs from adult hemoglobin in terms of 23DPG binding because _____________.

A

Fetal hemoglobin binds 23DPG less avidly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

The approximate affinity of carbon monoxide CO for hemoglobin compared to oxygen is _______________.

A

250 times greater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

The molecule formed when carbon monoxide binds to hemoglobin is __________.

A

Carboxyhemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

The effect of carbon monoxide binding on the oxygen-hemoglobin dissociation curve is _________.

A

Leftward shift making it harder to unload oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

The term for insufficient oxygen supply to tissues is ________.

A

hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

The transcription factor that is activated in response to hypoxia is _____________.

A

Hypoxiainducible factor 1a (HIF1a)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

The hormone stimulated by HIF1a to increase red blood cell production is ___________.

A

Erythropoietin EPO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Erythropoietin EPO is produced in the __________.

A

kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

The main form in which CO2 is transported in the blood is __________.

A

Bicarbonate (HCO3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

The enzyme that catalyzes the conversion of CO2 and water to carbonic acid is ________.

A

Carbonic anhydrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

The membrane protein that exchanges bicarbonate for chloride ions across the red blood cell membrane is _________.

A

Anion exchanger 1 (AE1) or Chloride-bicarbonate exchanger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

The effect the binding of oxygen to hemoglobin has on CO2 transport Haldane effect is ____________.

A

It promotes the release of CO2 from hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

The effect the binding of CO2 to hemoglobin has on oxygen transport Bohr effect is ___________.

A

It promotes the release of oxygen from hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

During exercise, the oxygen-hemoglobin dissociation curve shifts __________.

A

rightward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

At high altitude, the oxygen-hemoglobin dissociation curve shifts ___________.

A

rightward

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

The effect of exercise on oxygen consumption is _____________.

A

increased oxygen consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

The effect of high altitude on oxygen availability is ___________.

A

decreased oxygen availability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

The main physiological adaptations to high altitude are __________.

A

Increased ventilation, Increased red blood cell production, Increased 23DPG levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

The primary function of the respiratory system is ____________.

A

Gas exchange: oxygen uptake and carbon dioxide removal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

The two main components of the respiratory system are _________ and _______.

A

lungs, airways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

The tiny air sacs in the lungs where gas exchange occurs are the __________.

A

alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

The muscle that separates the thoracic cavity from the abdominal cavity and is involved in breathing is the ________.

A

diaphragm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

During inhalation, the volume of the thoracic cavity _________.

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

During inhalation, the pressure in the thoracic cavity ________.

A

decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

The law that describes the relationship between pressure and volume of a gas is _________.

A

Boyle’s law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

The pressure gradient that drives oxygen from the alveoli into the blood is the ______________.

A

partial pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

The pressure gradient that drives carbon dioxide from the blood into the alveoli is the ______________.

A

partial pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

The typical breathing rate at rest is ___________.

A

1220 breaths per minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

The condition where breathing is difficult or labored is _______________.

A

dyspnea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

The condition where breathing stops temporarily during sleep is _______________.

A

sleep apnea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

The most common expressed protein in a red blood cell is __________, which is “band 3” on a western blot.

A

AE1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

True or False: Carbon dioxide and water going bicarb and protons always requires carbonic anhydrase.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What are the four components of the respiratory control system?

A
  1. Chemoreceptors, 2. Mechanoreceptors, 3. Brain Stem (medulla & pons), 4. Respiratory muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What part of the brain provides voluntary control of respiration?

A

Cerebral Cortex (But, ‘overruled’ by Brain Stem)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What is apneusis?

A

Sustained effort for inhalation unrelieved by exhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

True or False: The pons is the most essential portion of the brain needed for respiration.

A

False, it’s the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What is the function of the pneumotaxic center?

A

Sends inhibitory impulses on inspiration, preventing overdistension of the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Smooth, steady inspiration due to ramp signals allows for _________(less/more) work by the respiratory system.

A

Less, smaller pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

True or False: Smooth, steady expiration prevents the lungs from collapsing.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What nerve innervates the diaphragm?

A

Phrenic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What nerve innervates the tongue muscles (except palatoglossus)?

A

Hypoglossal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Describe the diaphragm’s electroneurographic activity during normal inspiration.

A

Begins weakly and increases steadily in a ramp manner for about 2 seconds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What is the primary method for controlling the rate of respiration?

A

Changing the rate of increase of the ramp signal in the diaphragm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What is the function of the inspiratory “off-switch” signal?

A

Offsets the large elastic recoil of the lungs at the end of inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

True or False: Central chemoreceptors directly measure Pco2.

A

False, they measure it indirectly by measuring pH (H+ ions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Define eupnea

A

Normal, good, unlabored ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Describe the breathing pattern in apneustic breathing.

A

Protracted gasping inhalation followed by short, inefficient exhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

In terms of the respiratory gases and reactions, _____ can pass the BBB, but _______ and ________ cannot.

A

CO2, H+ and HCO3-

105
Q

What can cause apneustic breathing?

A

Damage to the vagus nerve or pneumotaxic center, or drugs like ketamine

106
Q

What is the leading cause of central sleep apnea syndrome (CSAS)?

A

Instability in the feedback control involved in the chemical regulation of breathing

107
Q

What is the typical breathing pattern during cardiac arrest?

A

Gasping (Causes include cerebral ischemia, extreme hypoxia, or anoxia)

108
Q

What causes ataxic breathing?

A

Damage to the medulla oblongata

109
Q

Chemoreceptors are _____ Type I cells.

A

glomus

110
Q

The net pressure for air movement is calculated as ___________. A negative value indicates air flows ______(in/out), while a positive value indicates air flows _____(in/out).

A

Pnet = Palv – Patm, in, out

111
Q

__________ refers to the distensibility of the lung.

A

Compliance

112
Q

On a pressure-volume loop, the slope represents ________.

A

compliance

113
Q

The difference between inflation and deflation routes on a pressure-volume loop is called __________.

A

hysteresis

114
Q

In the pressure-volume loop for an isolated lung, hysteresis is eliminated when ___________ is eliminated.

A

surface tension

115
Q

At functional residual capacity, the pressure in the lung-chest wall system is ____.

A

0

116
Q

Emphysema increases lung compliance, leading to a ________(higher/lower) FRC.

A

higher

117
Q

Fibrosis decreases lung compliance, leading to a ________(higher/lower) FRC.

A

lower

118
Q

Floppy lungs seen in emphysema make airways more prone to collapse during _________.

A

expiration

119
Q

Surface tension is the force that acts to pull a liquid’s surface molecules together at the __________.

A

air interface

120
Q

According to Laplace’s Law, the pressure inside a sphere is equal to ______, where T represents surface tension and r represents the radius.

A

2T/r

121
Q

Smaller alveoli tend to ________ into larger ones.

A

collapse

122
Q

________ prevents the collapse of smaller alveoli.

A

Surfactant

123
Q

Most of the elastic recoil in a normal lung is due to ___________.

A

surface tension

124
Q

Surfactant is a complex mixture of ________.

A

lipoprotein

125
Q

Surfactant reduces surface tension, elastic recoil, and effort to inflate, ultimately ___________ compliance.

A

increasing

126
Q

The hereditary absence of the surfactant protein ______ is fatal.

A

SP-B

127
Q

Approximately ______ of surfactant is lipid, with about half of that being DPPC.

A

90%

128
Q

The synthesis and expression of surfactant is low until ______.

A

birth

129
Q

The two implications of Laplace’s law in premature births are reduced collapsing pressure in ____________ and increased lung ___________, leading to a reduction in the work of breathing.

A

small alveoli, compliance

130
Q

Poiseuille’s Law relates airflow to the pressure difference and _________ of the airways.

A

resistance

131
Q

__________ lowers the surface tension of water, increasing compliance.

A

Surfactant

132
Q

Increased bronchiolar __________ leads to less airway resistance.

A

diameter

133
Q

_________ is characterized by intermittent attacks in which airway smooth muscle contracts.

A

Asthma

134
Q

__________ involves the destruction of alveolar walls and loss of pulmonary capillaries.

A

Emphysema

135
Q

____________ involves excessive mucus production in bronchi and inflammatory changes in small airways.

A

Chronic bronchitis

136
Q

Airway resistance is greatest at ___________ and decreases steeply as lung volume increases.

A

residual volume

137
Q

Changes in compliance shift volume for any given pressure difference, thus affecting __________.

A

airway resistance

138
Q

During inspiration, the ___________ move upward and outward.

A

lower ribs

139
Q

Normal expiration occurs via the _________ of inspiratory muscles.

A

relaxation

140
Q

The main muscle of inspiration is the _________.

A

diaphragm

141
Q

The ______________ are accessory muscles of inspiration.

A

external intercostals

142
Q

The ___________, ____________, and __________ are muscles of forced expiration.

A

internal intercostals, external oblique, rectus abdominis

143
Q

During forced expiration, the contraction of expiratory muscles increases ________.

A

Pip

144
Q

In emphysema, diminished elastic recoil leads to a lower ___.

A

Ptp

145
Q

Forced expiration in individuals with emphysema can lead to ______________.

A

airway collapse

146
Q

At the beginning of inspiration, the pressure difference (Δ) between the alveoli and the atmosphere is ______.

A

25-20

147
Q

At the end of inspiration, the pressure difference (Δ) between the alveoli and the atmosphere is ______.

A

15-20

148
Q

During the respiratory cycle, when airflow is 0, forces are ________.

A

balanced

149
Q

The transpulmonary pressure (Ptp) is calculated as _________.

A

Palv - Pip

150
Q

To calculate alveolar pressure (Palv), use the equation: __________.

A

Palv = Ptp + Pip

151
Q

An increase in tidal volume ________(increases/decreases) ventilation.

A

increases

152
Q

An increase in breathing rate ________(increases/decreases) ventilation.

A

increases

153
Q

A decrease in tidal volume __________(increases/decreases) ventilation.

A

decreases

154
Q

A decrease in breathing rate __________(increases/decreases) ventilation.

A

decreases

155
Q

Lung ‘collapse’ pressure is represented by ____.

A

Ptp

156
Q

Chest wall ‘expand’ pressure is represented by _____.

A

-Pcw

157
Q

Greater pressure difference for a similar volume change results in ________.

A

more work

158
Q

The process of _________ is crucial for gas exchange in the lungs.

A

diffusion

159
Q

A typical individual consumes approximately 250 ml/min of ____.

A

O2

160
Q

The production of _____ in a typical individual is around 200 ml/min.

A

CO2

161
Q

When describing gas in the gas phase, the abbreviation ______ is used, which stands for body temperature, ambient pressure, and saturation with water vapor.

A

BTPS

162
Q

_____ which stands for standard temperature, standard pressure, and dry gas, is used to describe gas in the liquid phase.

A

STPD

163
Q

To convert gas volume from BTPS to STPD, the following equation is used: Gas volume at BTPS * 273/310 * (PB - 47)/760 = __________.

A

Gas volume at STPD

164
Q

__________ is represented by the symbol PB.

A

Barometric pressure

165
Q

At a temperature of 37°C, the water vapor pressure is ___ mmHg.

A

47

166
Q

________ states that there is an inverse relationship between pressure and volume.

A

Boyle’s Law

167
Q

In the airways, air undergoes __________.

A

humidification

168
Q

The sum of the partial pressures of all gases in a mixture is equal to the total pressure, as stated by _______________.

A

Dalton’s Law of Partial Pressures

169
Q

In dry air, the partial pressure of oxygen (PO2) is ________.

A

159.6 mmHg

170
Q

The partial pressure of inspired oxygen (PIO2) is _______.

A

149.7 mmHg

171
Q

At sea level, the atmospheric pressure is approximately ____ mm Hg and the atmosphere comprises about _____ oxygen.

A

760, 21%

172
Q

Consequently, the PO2 at sea level is _____.

A

160 mmHg

173
Q

The partial pressure of oxygen in the alveoli (PAO2) is typically _______.

A

105 mmHg

174
Q

The partial pressure of carbon dioxide in the alveoli (PACO2) is normally _________.

A

40 mmHg

175
Q

Under normal circumstances, the alveolar and arterial partial pressures of CO2 reach equilibrium, meaning ____________.

A

PACO2 = PaCO2

176
Q

The relationship between a gas’s partial pressure and its concentration in a liquid is described by ___________.

A

Henry’s Law

177
Q

According to Henry’s Law, Cx stands for the value of ________ in solution, excluding any __________.

A

free gas, bound gas

178
Q

True or False: It is possible for two gases to have the same partial pressures but different dissolved concentrations.

A

True

179
Q

______ Law provides a description of the diffusion of gases.

A

Fick’s

180
Q

True or False: The driving force behind the diffusion of gases is the partial pressure difference (ΔP), not the concentration difference.

A

True

181
Q

The diffusion coefficient (D) for CO2 is ____ times greater than that of O2.

A

20

182
Q

For a given partial pressure difference, the diffusion rate of CO2 is 20 times _______(slower/faster) compared to O2.

A

faster

183
Q

The lung O2 diffusion capacity (DL) is influenced by all parameters in Fick’s Law except for _____ and the time it takes for binding to hemoglobin.

A

ΔP

184
Q

As per Fick’s Law, the rate of diffusion is directly proportional to the _________ and _______________ difference, while it is inversely proportional to the __________ of the barrier.

A

surface area, partial pressure, thickness

185
Q

The partial pressures of both O2 and CO2 are influenced by _________ ventilation.

A

alveolar

186
Q

The barriers that impede gas diffusion include the alveolar epithelium, _____________, and capillary endothelium.

A

interstitial space

187
Q

The relationship between ___________ capacity and the resistance to diffusion in series is represented by the equation 1/DL = 1/DM + 1/(q*Vc).

A

diffusion

188
Q

Although _______________ can be used to measure DL, it is important to use it at a low concentration for safety reasons.

A

carbon monoxide (CO)

189
Q

Emphysema leads to a decrease in DL due to a reduced ___________.

A

surface area

190
Q

An increase in the _________ of the diffusion barrier due to fibrosis results in a decrease in DL.

A

thickness

191
Q

DL is reduced in pulmonary edema as a result of the increased thickness of the _________ barrier.

A

diffusion

192
Q

________ causes a decrease in DL because of reduced hemoglobin levels.

A

Anemia

193
Q

Under normal conditions, blood O2 achieves equilibrium with alveolar O2 within _________ of the capillary length.

A

one-third

194
Q

Gases in solution can exist in three forms: dissolved gas, ________ gas, and chemically modified gas.

A

bound

195
Q

_________ is unique among “air gases” in that it exists solely in dissolved form.

A

Nitrogen (N2)

196
Q

The total concentration of a gas in solution is determined by the following equation: Total [gas] = [dissolved gas] + [bound gas] + [______________________].

A

chemically modified gas

197
Q

The conversion of CO2 to bicarbonate is described by the equation CO2 + H2O ⇌ H2CO3 ⇌ HCO3- + ______.

A

protons (H+)

198
Q

The ___________ of tissues is reflected in the partial pressure of CO2.

A

metabolic activity

199
Q

A lower arterial PO2 can be attributed to __________.

A

shunt pathways

200
Q

___________, which can arise in conditions like strenuous exercise and emphysema, can impact gas exchange.

A

Diffusion limitation

201
Q

______________, which can occur under normal conditions, can affect gas exchange.

A

Perfusion limitation

202
Q

___________ (Dt) refers to the duration available for gas exchange.

A

Contact time

203
Q

Factors that can contribute to ____________ include decreased diffusion capacity, increased diffusion distance, increased perfusion rate, and decreased contact time.

A

diffusion limitation

204
Q

_________________ can be influenced by factors such as increased diffusion capacity, decreased diffusion distance, decreased perfusion rate, and increased contact time.

A

Perfusion limitation

205
Q

The capacity of blood to transport O2 can be compared to the capacity of _________, while blood flow is akin to _________.

A

rail cars, train speed

206
Q

As one ascends to higher altitudes, the barometric pressure _________, but the fractional concentrations of individual gases remain ___________.

A

decreases, unchanged

207
Q

The two main limitations of gas exchange are limitations due to the _______ process and limitations due to _______.

A

diffusion, blood flow

208
Q

The symbol for ventilation is _______ and the symbol for perfusion is _______.

A

VA, Q

209
Q

The ratio of ventilation to perfusion is represented as the _______ ratio.

A

VA/Q

210
Q

Compared to the systemic circulation, the pulmonary circulation has _______ pressure and _______ resistance.

A

low, low

211
Q

The pressure difference driving blood flow in the pulmonary system is approximately _______ mm Hg.

A

4

212
Q

Pulmonary blood flow is regulated by altering the _______ of arteriolar smooth muscle via local vasoactive substances, primarily _______.

A

resistance, O2

213
Q

A decrease in PAO2 below _______ mm Hg leads to _______ in the pulmonary vasculature.

A

70, vasoconstriction

214
Q

Global vasoconstriction at high altitude results in an increase in total pulmonary _______ resistance.

A

vascular

215
Q

The mechanism of hypoxic vasoconstriction involves the inhibition of _______ channels in smooth muscle cells.

A

K+

216
Q

Bronchial circulation comprises a small fraction (around _______%) of left ventricular output.

A

2

217
Q

The tracheobronchial tree receives systemic blood from the _______ circulation.

A

bronchial

218
Q

Most of the blood from the bronchial circulation empties into the _______ vein, creating a “right-to-left shunt.”

A

pulmonary

219
Q

The pulmonary circulation receives _______% of the cardiac output from the right ventricle.

A

100

220
Q

Pulmonary blood flow is approximately equal to _______.

A

cardiac output

221
Q

Blood flow through the heart and lungs follows this path: _______ → LV → systemic → RA → RV → pulmonary → _______ →.

A

LA, LA

222
Q

An increase in alveolar transmural pressure gradient leads to an increase in _______, which has a significant impact on pulmonary vascular resistance (PVR).

A

alveolar volume

223
Q

As alveolar volume (VL) increases, alveolar vessels experience an increase in _______ and a decrease in _______, leading to increased resistance.

A

length (L), radius (r)

224
Q

Conversely, as lung volume increases, extra-alveolar vessels experience _________ resistance.

A

decreased

225
Q

The volume at which pulmonary vascular resistance is at its lowest is _________________.

A

functional residual capacity (FRC)

226
Q

An increase in cardiac output from the right ventricle leads to a _______ in pulmonary vascular resistance.

A

decrease

227
Q

When lying down, blood flow distribution to the upper and lower regions of the lung is more _______.

A

even

228
Q

Gravity causes blood flow per unit volume to be greater in the more _______ regions of the lung.

A

gravity-dependent

229
Q

In a standing individual, alveolar pressure (PA) is _______ than arterial pressure (Pa) at the apex of the lung.

A

greater

230
Q

In contrast, at the base of the lung in a standing individual, arterial pressure (Pa) is _______ than alveolar pressure (PA).

A

greater

231
Q

Ventilation (VA) and perfusion (Q) are _______ at the top (zone 1) and _______ at the bottom (zone 3) of the lung.

A

low, high

232
Q

Importantly, ventilation and perfusion do not change _______.

A

proportionally

233
Q

Pulmonary blood flow is influenced by several passive factors, including _______, _______, and _______.

A

gravity, alveolar pressure, lung volume

234
Q

In areas of the lung with ventilation but no perfusion, the PO2 will be _______ and the PCO2 will be _______.

A

high, low

235
Q

Conversely, in areas with perfusion but no ventilation, PO2 will be _______ and PCO2 will be _______.

A

low, high

236
Q

The apex of the lung has a _______ VA/Q ratio compared to the base.

A

higher

237
Q

The normal VA/Q ratio for the entire lung is _______.

A

0.8

238
Q

A normal VA/Q ratio results in a PaO2 of _______ mm Hg and a PaCO2 of _______ mm Hg.

A

100, 40

239
Q

VA/Q mismatches can arise due to _______, _______, _______, and _______.

A

hypoventilation, ventilation of non-perfused regions, right-to-left shunts, left-to-right shunts.

240
Q

Hypoventilation leads to _______, which triggers _______ to redirect blood flow to better-ventilated areas.

A

hypoxia, vasoconstriction

241
Q

A right-to-left shunt involves cardiac output bypassing the _______, which normally accounts for about _______% of cardiac output.

A

alveoli

242
Q

An increased shunt fraction results in _______.

A

hypoxemia

243
Q

Left-to-right shunts are more _______ and do not cause hypoxemia.

A

common

244
Q

Left-to-right shunts can be caused by conditions such as _______ or _______.

A

patent ductus arteriosus, traumatic injury

245
Q

A left-to-right shunt leads to _______ PO2 in the right side of the heart.

A

elevated

246
Q

Ventilation of non-perfused regions, as seen in pulmonary embolism, results in pulmonary capillary blood with _______ PO2.

A

high

247
Q

In a right-to-left shunt, there is _______ gas exchange, resulting in pulmonary capillary blood with a PO2 similar to _______.

A

mixed venous PO2 (40 mm Hg)

248
Q

Reduced or absent blood flow due to a shunt leads to _______ ventilation and _______ CO2 mixing.

A

low, no

249
Q

The Bohr effect describes the phenomenon where, as PCO2 increases, the O2 content of blood _______.

A

decreases

250
Q

The Haldane effect describes the phenomenon where, as PO2 increases, the CO2 content of blood _______.

A

decreases

251
Q

Moving from a PCO2 of 44 mm Hg to 35 mm Hg allows for the same total O2 content to be carried at a _______ PO2.

A

lower

252
Q

Therefore, reduced PCO2 enables the blood to carry a _______ total O2 content at the same PO2.

A

greater

253
Q

It is important to note the difference in units between the axes in the O2-CO2 diagrams: _______ vs. _______.

A

mm Hg, mL/dL

254
Q

If a patient’s PaCO2 is 50 mm Hg, the corresponding total CO2 content at a PO2 of 100 mm Hg would be approximately _______ ml/dL.

A

52

255
Q

Pulmonary blood flow is influenced by _______ factors, including gravity and alveolar pressure, and _______ factors, such as hypoxic vasoconstriction.

A

passive, active

256
Q

Dry air contains ____% nitrogen, ______% oxygen, _____% argon, and _____% carbon dioxide.

A

78.09%, 20.95%, 0.93%, 0.039%

257
Q

Contraction & constriction occur in the airways due to __________ (muscarinic) receptors.

A

cholinergic

258
Q

Relaxation & dilation occur in the airways due to __________ (beta2) receptors.

A

adrenergic

259
Q

True or False: The diaphragm and intercostals are innervated by the somatic motor system.

A

True