Respiratory Physiology Flashcards
1
Q
How many generation of airways do you find in the respiratory system?
A
23
2
Q
How many alveoli are present in the respiratory system?
A
500 million
3
Q
What is the sympathetic effect on smooth muscle of the airways?
A
Smooth Muscle Relaxation (Beta-2)
4
Q
What is the parasympathetic effect on smooth muscle of the airways?
A
Smooth Muscle Contraction (Muscarinic)
5
Q
No gas exchange; Transports gas to the lungs; Nose to Terminal Bronchioles
A
Conducting Zone
6
Q
Areas of gas exchange; Respiratory Bronchioles, Alveolar Ducts, Alveolar sacs
A
Respiratory Zone
7
Q
96-98% of surface area; For gas exchange
A
Type I Pneumocyte
8
Q
2-4% of surface area; For surfactant production
A
Type II Pneumocyte
9
Q
Keep alveoli free of dust and debris
A
Alveolar macrophages
10
Q
Produce mucus
A
Goblet cells, Submucosal Glands
11
Q
May play a re in epithelial regeneration after injury by secreting protective GAGs
A
Clara Cells (Club Cells)
12
Q
Carries deoxygenated blood to the lungs
A
Pulmonary Circulation
13
Q
Carries oxygenation blood to the lungs
A
Bronchial Circulation
14
Q
4 Basic Lung volumes
A
Inspiratory Reserve Volume (IRV)Tidal Volume (TV)Expiratory Reserve Volume (ERV)Residual Volume (RV)
15
Q
What is a Lung Capacity?
A
Sum of two or more lung volumes (Inspiratory Capacity (IC), Functional Residual Capacity (FRC), Vital Capacity (VC), Total Lung Capacity (TLC)
16
Q
How do you measure lung Volumes and Capacities?
A
Spirometry
17
Q
Only Lung Volume that cannot be measured directly by spirometry?
A
Residual Volume, FRC, TLC
18
Q
Amount of Air inspired/expired during quiet breathing?
A
Tidal Volume 500ml: 150ml in the conducting zone, 350ml in the respiratory zone
19
Q
Differences in terms of Lung Volumes and Capacities among sexes?
A
20-25% lower in females
20
Q
Maintains oxygenation in between breaths?
A
Residual Volume
21
Q
Equilibrium or Resting Volume of the Lungs?
A
Functional Residual Capacity (FRC) (marker of Lung function)
22
Q
Factors that increases Vital Capacity (VC)?
A
Body size, Male gender, Physical Conditioning, youth
23
Q
Anatomic Dead Space + Alveolar Dead Space; Total volume of the lungs that does NOT participate in gas exchange
A
Physiologic Dead Space
24
Q
Air in the conducting zone
A
Anatomic Dead Space (150ml)
25
Air in the alveoli not participating in gas exchange due to V/Q mismatch (0ml)
Alveolar Dead Space
26
Volume of air moved into and out of the lungs per unit time
Ventilation Rate
27
Total rate of air movement in/out of the lungs
Minute Ventilation
28
Minute ventilation corrected for physiologic dead space
Alveolar Ventilation
29
What happens to the FEV1 and FVC in patients with obstructive and restrictive lung diseases?
Decreased
30
What is the FEV1/FVC ratio of a healthy person?
0.8
31
What happens to the FEV1/FVC ratio in patients with obstructive and restrictive lung diseases respectively?
Obstructive: DecreasedRestrictive: Normal to Increased
32
Normal Inspiration
Active (Diaphragm)
33
Forced Inspiration
External Intercostals
34
Normal Expiration
Passive
35
Forced Expiration
Internal Intercostals
36
Change in volume for a given change in pressure?
Compliance
37
What do you call the difference between compliance curves during inspiration and expiration of an air-filled lung?
Hysteresis
38
What is the basis for hysteresis?
Surface tension at air-liquid interface
39
Loss of elastic fiber, increased compliance, decreased elasticity, increased FRC, barrel-shaped chest
Emphysema
40
Stiffening of lung tissue, decreased compliance, increased elasticity, decreased FRC
Fibrosis
41
Force caused by water molecules at the air-liquid interface that tends to minimize surface area
Surface Tension
42
Active Component
DPPC (main component: water)
43
Mechanism of DPPC reducing surface tension
Amphiphatic Nature (hydrophobic and hydrophilic)
44
Effect of surfactant on lung compliance
Increases
45
Start of and maturation of surfactant levels respectively
24th and 35th week
46
Test, Treatment for RDS?
Amniotic L-S Ratio; Steroids; Surfactant
47
Formula for Airflow
Ohm's Law
48
Formula for Airway Resistance?
Poiseuille's Law
49
Factors in airway resistance?
Sympathetic: decreasesParasympathetic: increasesLung volume: decreasesViscosity of inspired air: increases
50
Formula for transpulmonary pressure
Alveolar pressure-Intrapleural pressure
51
If transpulmonary pressure is positive
Lungs expand
52
If transpulmonary pressure is negative
Lungs collapse
53
Transpulmonary pressure in healthy persons
Positive (lungs always open)
54
Transpulmonary pressure in patients with emphysema during forced expiration
Negative (lungs collapse)
55
Law implying that an increase in Lung Volume will decrease pressure?
Boyle's Law
56
Law of mixed gases?
Dalton's Law of Partial Pressure
57
Law of gases dissolved in solution?
Henry's law for concentration of dissolved gases
58
Law for transfer of gases through simple diffusion in cell membranes or capillary walls?
Fick's law of diffusion
59
Driving force for diffusion
Partial Pressure Difference
60
Ability of the respiratory membrane to exchange as between the alveoli and the pulmonary blood
Diffusing Capacity
61
Diffusing capacity for O2
At rest: 21ml/min/mmHgMaximal exercise: 65ml/min/mmHg
62
Diffusing capacity for CO2
At rest: 400-450ml/min/mmHgMaximal exercise: 1200-1300ml/min/mmHg
63
What are the forms of gases in solutions?
Dissolved gas, Bound gas, Chemically Modified gas
64
What is the only form of gas that contributes to partial pressure?
Dissolved gas
65
What is the only gas in inspired air found exclusively as dissolved gas?
Nitrogen
66
Difference between arterial PAO2 and PaO2; Normally very small; Increases in cases of large physiologic shunt
A-a gradient
67
Gas equilibrates with the pulmonary capillary near the start of the pulmonary capillary; Diffusion of gas increased only by increasing blood flow
Perfusion-Limited Gas Exchange
68
Gas does Not equilibrate even until the end of the pulmonary capillary; CO and O2 during strenuous exercise and disease states
Diffusion-Limited Gas Exchange
69
Normal O2 Transport
Perfusion-limited
70
Equilibration of O2 at sea level occurs at
1/3 the distance of Pulmonary Capillary
71
O2 transport in strenuous exercise, disease states
Diffusion-limited
72
O2 Transport in high altitude
Slower equilibration
73
Equilibration of O2 at high altitude occurs
2/3 the distance of Pulmonary Capillary
74
Percentage of Dissolved O2
2%
75
Percentage of O2 bound to HgB
98%
76
HgB with attached O2
Oxyhemoglobin
77
HgB without attached O2
Deoxyhemoglobin
78
HgB with Fe3+; Doesn't bind O2
Methemoglobin
79
Alpha2, Gamma2, Higher affinity for O2
Fetal Hemoglobin (HbF)
80
AlphaA2, BetaS2, sickled RBCs, less affinity for O2
Hemoglobin S (HbS)
81
Max O2 binding with HgB
O2 binding capacity
82
(O2 binding capacity x %saturation) + dissolved O2
O2 content
83
Cardiac output x O2 content
O2 delivery
84
% of blood that gives up its O2 as it passes through the tissues
Utilization Coefficient
85
Sigmoidal in shape; Exhibits Positive Cooperativity
O2-HgB Dissociation Curve
86
O2-HgB Dissociation Curve: Increased unloading of O2 to HgB, Increased P50, Due to increased Carbon dioxide, acidosis, 2,3 BPG, exercise & temperature
Shift to the RIGHT
87
O2-HgB Dissociation Curve: Increased binding of O2 to HgB, Decreased P50, Due to Increased carbon monoxide, HbF
Shift to the LEFT
88
3 main forms of CO2 in the blood
CarbaminohemoglobinDissolved CO2HCO3
89
CO2 bound to HgB
Carbaminohemoglobin
90
CO bound to HgB
Carboxyhemoglobin
91
Cl-HCO3 exchange in the RBC
Chloride shift (using Band Three Protein)
92
O2 affecting affinity of CO2/H to HgB
Haldane effect
93
CO2/H affecting affinity of O2 to HgB
Bohr effect
94
Pulmonary Circulation: Pressure
95
Pulmonary Circulation: Resistance
96
Pulmonary Circulation: Blood Flow
= Systemic Circulation
97
Pulmonary Blood Flow: Supine
Uniform throughout Lungs
98
Pulmonary Blood Flow: Standing
Apex: Lowest; Base: Highest
99
Effect of Hypoxia (low PAO2) on Pulmonary Arteries
Vasoconstriction
100
Causes of Pulmonary Global Hypoxic Vasoconstriction
High Altitude; Fetal Circulation
101
Other Lung Vasoactive substances
TXA2, PGI2
102
Causes Airway constriction
Leukotrienes
103
Lung Zones: Local Alveolar Capillary Pressure
Zone 1
104
Lung Zones: Local Alveolar Capillary Systolic Pressure > Alveolar Air Pressure during systole but less than that during diastole
Zone 2
105
Lung Zones: Local Alveolar Capillary Pressure > Alveolar Air Pressure throughout the cycle
Zone 3
106
What lung zones do we see in the apex of the lungs?
Zone 2 and Zone 3
107
What lung zones do we see in the Base of the lungs?
Zone 3
108
What lung zones do we see in lying position or during exercise throughout the lungs?
Zone 3
109
What lung zones do we see in cases of Pulmonary hemorrhage or Positive pressure ventilation?
Zone 1
110
Diverted/rerouted blood flow
Shunt
111
Made up of bronchial circulation and coronary circulation
Physiologic shunts
112
(+) Hypoxemia, decreased PaO2, cannot be corrected by having the person breathe a high O2 gas
Right-to-Left Shunts
113
(-) Hypoxemia, increased PaO2 on the R side of the heart
Left-to-Right Shunts
114
Normal V/Q Ratio
0.8
115
High V/Q
High PO2, Low PCO2
116
Low V/Q
Low PO2, High PCO2
117
Creates the basic respiratory rhythm; Contains the Dorsal Respiratory Group (DRG), Ventral Respiratory Group (VRG) and Central Chemoreceptors
Medulla
118
Modifies the Basic Respiratory Rhythm; Contains the Apneustic and Pneumotaxic Centers
Pons
119
Site of highest ventilation
Base of the lungs
120
Site of highest perfusion
Base of the lungs
121
Site of highest V/Q ratio
Apex of the lungs
122
Ventilated area of the lungs with (-) perfusion (V/Q = infinity); Alveolar gas has same composition as humidified inspired air (PAO2 = 150mmHg & PACO2 = 0)
Dead space
123
Perfusion of lungs with no ventilation (V/Q = zero); Pulmonary Capillary blood has sane composition as mixed venous blood: PaO2=40mmHg & PaCO2=46mmHg
Shunt
124
Inspiratory Center; Control Basic Rhythm; For normal Inspiration
Dorsal Respiratory Group (DRG)
125
Overdrive mechanism during exercise; For forced inspiration and expiration
Ventral Respiratory Group (VRG)
126
Found in the lower pins; For prolonged inspiratory gasp (decreases respiratory rate)
Apneustic Center
127
Found in the upper pons; limits time for inspiration (increases respiratory rate)
Pneumotaxic Center
128
Found in the ventral medulla; Respond directly to CSF-H (increases RR)
Central Chemoreceptors
129
Responds mainly to PaO2
Peripheral Chemoreceptors
130
Stimulated by Lung Distension; Initiates Hering-Breuer Reflex that decreases Respiratory Rte by prolonging expiratory time
Lung Stretch Receptors
131
Stimulated by Limb movement; Causes anticipatory increase in respiratory rate during exercise
Joint & Muscle Receptors
132
True or False: In exercise, itnis hypoxia that drives the increase in ventilation
False
133
Stimulated by noxious chemicals; Causes bronchoconstriction and increases the RR
Irritant Receptors
134
Found in Juxtacapillary areas; Stimulated by pulmonary capillary engorgement; Causes rapid shallow breathing and responsible for feeling of dyspnea
J Receptors
