Physiology Flashcards
1
Q
Air that can still be breathed in after normal inspiration
A
Inspiratory reserve volume
2
Q
Air that moves into lung with each quiet inspiration
A
Tidal volume
3
Q
Volume breathed in during tidal volume
A
500 ml
4
Q
Air that can still be breathed out after normal expiration
A
Expiratory Reserve Volume
5
Q
Air that can still be exhaled after normal exhalation
A
Inspiratory Capacity
6
Q
Lung volumes that make up IC
A
IRV + TV
7
Q
Volume of gas in lungs after normal expiration
A
Functional Reserve Capacity
8
Q
Lung volumes that make up FRC
A
ERV and RV
9
Q
Maximum amount of gas that can be expired after a maximal inspiration
A
Vital Capacity
10
Q
Lung volumes that make up VC
A
IRV, TV, ERV
11
Q
Volume of gas present in lungs after a maximal expiration
A
Tidal Volume
12
Q
Anatomic dead space of conducting airways plus alveolar dead space
A
Physiologic dead space
13
Q
Formula for Physiologic dead space
A
V(D) = V(T) x PaCO2 - P(E)CO2/PaCO2
14
Q
In healthy lungs what does physiologic dead space approximate
A
Anatomical dead space
15
Q
When part of the respiratory zone becomes unable to perform gas exchange
A
Pathologic dead space
16
Q
Formula for Ventilation
A
V(A) = V(E) - V(D)
17
Q
Total volume of gas enter lungs per minute
A
Minute ventilation: V(E)
18
Q
Formula for minute ventilation
A
V(E) = V(T) x RR
19
Q
Volume of gas per unit time that reaches alveoli
A
Alveolar ventilation: V(A)
20
Q
Formula for alveolar ventilation
A
V(A) = [V(T) - V(D)] x RR
21
Q
Normal V(T) in healthy individuals
A
500 ml/breath
22
Q
Normal physiologic dead space in healthy individuals
A
150 ml/breath
23
Q
Tendency for lungs to collapse inward and chest wall to spring forward
A
Elastic recoil
24
Q
When is pulmonary vascular resistance at minimum
A
at FRC
25
What is the airway and alveolar pressures at FRC
Zero
26
High compliance of lungs is seen in which conditions
Emphysema and aging
27
Low compliance of lungs is seen in which conditions
Pulmonary fibrosis, pneumonia, NRDS, pulmonary edema
28
At what lung capacity are inward pull of lungs balanced by outward pull of chest wall
FRC
29
At what lung capacity is respiratory system pressure atmospheric
FRC
30
Which form of hemoglobin has low affinity for O2
Deoxygenated form
31
What are the different conformations of hemoglobin
Tense and relaxed
32
Conformation of deoxygenated hemoglobin
Tense
33
Which form of hemoglobin has high affinity for O2
Relaxed
34
Cause for increased affinity for O2 in HbF
Decreased affinity for 2,3 BPG
35
Type of air flow found in median bronchi
Turbulent flow
36
Type of air flow found in terminal bronchioles
Slow laminar flow
37
Airways with highest airway resistance
Medium bronchi
38
Airways with lowest airway resistance
Terminal bronchioles
39
Presents with chocolate-colored blood and cyanosis
methemoglobinemia
40
Treatment for methemoglobinemia
Methylene blue and vitamin C
41
Form of iron in hemoglobin that bind O2
Fe2+ (reduced state)
42
Oxidized form of Hb that does not bind O2 as readily but has high affinity for cyanide
Methemoglobin
43
Treatment for cyanide poisoning
Nitrites followed by hydroxocobalamin and thiosulfate
44
When would you induce methemoglobinemia
In cyanide poisoning (excreted renally)
45
Form of Hb bound to CO in place of O2
Carboxyhemoglobin
46
Result of carboxyhemoglobin on O2-dissociation curve
Left shifts curve causing decreased O2 unloading to tissues
47
Treatment in patient presenting with headaches, dizziness and cherry-red skin after smoke exposure
100% O2 and hyperbaric chamber
48
Percentage of carboxyhemoglobin in healthy individuals
3%
49
Percentage of carboxyhemoglobin in smokers
10-15%
50
Percentage of carboxyhemoglobin in CO poisoning
Greater than 15%
51
Type of Hb in patient exposed to nitrites or benzocaine
Methemoglobin
52
Form of iron with decreased O2 affinity and increased cyanide affinity
Fe3+
53
Conditions that promote left-shift in O2-dissociation curve
Increased pH
| Decreased temp, H+, CO2
54
Conditions that promote right-shift in O2-dissociation curve
Decreased pH
| Increased temp, H+, CO2
55
What type of curve does HbF have
Left-shifted O2-dissociation curve
56
O2 content formula
O2 content = (1.34 x Hb x SaO2) + (0.003 x PaO2)
57
Amount of O2 1 g of Hb can bind
1.34 ml O2
58
Normal amount of Hb in blood
15g/dL
59
O2 saturation and PaO2 with decreased Hb
Normal
60
O2 content of arterial blood with decreased Hb
Decreased
61
What does O2 delivery to tissues depend on
Cardiac out x O2 content of blood
62
Hb concentration in CO poisoning
Normal
63
Hb concentration in anemia
Decreased
64
Hb concentration in polycythemia
Increased
65
Percent O2 sat of Hb in CO poisoning
Decreased
66
Percent O2 sat of Hb in anemia
Normal
67
Percent O2 sat of Hb in polycythemia
Normal
68
PaO2 in CO poisoning
Normal
69
PaO2 in anemia
Normal
70
PaO2 in polycythemia
Normal
71
Total O2 content in CO poisoning
Decreased
72
Total O2 content in anemia
Decreased
73
Total O2 content in polycythemia
Increased
74
Effect of decreased P(A)O2 on pulmonary circulation
Vasoconstriction - shifts blood to well-ventilated regions of lungs
75
Effect of decreased O2 on systemic circulation
Vasodilation to increase blood flow
76
Gases that are perfusion limited
CO2, N2O, and O2 (healthy lung)
77
Gases that are diffusion limited
CO
78
How can diffusion be increased in perfusion-limited gases
Increasing blood flow
79
Emphysema effects on diffusion of gases
Decreased diffusion due to loss of alveoli
80
Fibrosis effects on diffusion of gases
Decreased diffusion due to increased alveolar thickness
81
Exercise effects on diffusion of O2
Diffusion increased due to increased blood flow
82
What is considered pulmonary HTN
Greater than 25 mmHg at rest
83
Consequence of pulmonary HTN
Cor pulmonale and subsequent right ventricular failure
84
Affect of inhalation on vessel resistance in lungs
Decreased arteriolar resistance; increased alveolar resistance
85
Volume of air remaining in lungs after maximal expiration
1 liter
86
Affect of exhalation on vessel resistance in lungs
Increased arteriolar resistance; decreased alveolar resistance
87
Mechanism of increased alveolar vessel resistance on inhalation
Increased lung volumes stretches alveolar vessels making them longer and smaller diameter
88
Mechanism of increased arteriolar vessels resistance on exhalation
Decreased lung volumes narrows arteriolar vessels increasing resistance
89
Loud P2 (second heart sound) at left upper sternal border - what is disease
Pulmonary HTN
90
Gold standard for diagnosing pulmonary HTN
Right heart catheterization
91
Non-invasive method to estimate pulmonary HTN
Echocardiogram
92
What can be visualized with echocardiogram
Estimate PA pressure and visualize right heart structures
93
Formula for calculating PVR
PVR = P(pa) - P(la)/CO
94
Formula for A-a gradient
A-a = P(A)O2 - PaO2
95
Normal A-a gradient range
10-15 mmHg
96
Alveolar gas equation
P(A)O2 = 150 mmHg - (PaCO2/0.8)
97
Conditions that increase A-a gradient
Hypoxemia: shunting, V/Q mismatch, fibrosis
98
Decreased O2 delivery to tissues
Hypoxia
99
Decreased PaO2
Hypoxemia
100
Loss of blood flow
Ischemia
101
Conditions that lead to hypoxia
Decreased CO, hypoxemia, anemia, CO poisoning
102
Conditions with increased A-a gradient that cause hypoxemia
V/Q mismatch, Diffusion limitation, right-to-left shunting
103
Conditions with normal A-a gradient that cause hypoxemia
High altitude, hypoventilation
104
V/Q ratio with airway obstruction
V/Q = zero
105
V/Q ratio with blood flow obstruction
V/Q = infinity
106
What lung zone has the greatest perfusion and ventilation
Zone 3 (base of lung)
107
What lung zone has wasted ventilation
Zone 1 (apex)
108
V/Q ratio at lung apex
V/Q = 3
109
Lung zone with wasted perfusion
Zone 3 (base)
110
V/Q ration at lung base
V/Q = 0.6
111
What condition creates anatomic shunting
Airway obstruction
112
Effect of 100% O2 in shunting
PaO2 does not improve
113
What condition creates physiologic dead space
Blood flow obstruction like pulmonary embolus
114
Effect of 100% O2 in physiologic dead space
PaO2 improves
115
Normal V/Q ratio
V/Q = 0.8
116
Effect of exercise on V/Q ratio
Apical capillaries vasodilate and V/Q approaches 1
117
Phenomenon in which CO2 is released from RBCs
Haldane effect
118
Location in body Haldane effect occurs
Lungs
119
Conditions that promote Haldane effect
Oxygenation of Hb promotes dissociation of H+ from Hb causing CO2 formation
120
Phenomenon in which O2 unloads from Hb
Bohr effect
121
Location in body Bohr effect occurs
Peripheral tissues
122
Conditions that promote Bohr effect
Increased H+ from tissue metabolism
123
Hb conformation that favors CO2 binding
Taut form
124
Form blood CO2 is primarily transported to lungs
HCO3- in plasma
125
Forms CO2 is transported from tissues to lungs
HCO3-, dissolved CO2, and HbCO2
126
CO2 and Hb combine to form which molecule
Carbaminohemoglobin
127
Effect of decreased atmospheric oxygen
Decreased PaO2 increases ventilation which decreases PaCO2 causing respiratory alkalosis leading to altitude sickness
128
Response of body to high altitude
```
Increased ventilation
Increased EPO
Increased 2,3 BPG
Increased mitochondria
Increased renal excretion of HCO3-
Increased pH
Decreased PO2, PCO2, HCO3-
```
129
Body's response to exercise
Increased CO2, O2 consumption, ventilation, pulmonary blood flow
Decreased pH
V/Q becomes more uniformed
130
Effect of exercise on venous O2 and CO2 content
Increased venous CO2 and decreased O2 content
131
Effect of exercise on arterial O2 and CO2 content
PaO2 and PaCO2 remain normal
