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