Pulmonary Review Flashcards
(160 cards)
1
Q
What are the structural components of the pulmonary system above the Trachea?
A
- Trachea
- Cartilage
- Larynx
- Epiglottis
- Pharynx
- Oral Cavity
- Nasal Passage
- Frontal Sinus
2
Q
What are the structural components of the pulmonary systems below the trachea and above the bronchioles?
A
- Ribs
- Lungs
- Superior Lobe
- Bronchi
- Bronchioles
- Diaphragm
- Heart
3
Q
What are the structural components of the pulmonary system after the bronchioles?
A
- Respiratory Bronchioles
- Smooth Muscles
- Pulmonary Artery
- Pulmonary Vein
- Alveoli
- Capillary Beds Cover All Alveoli
4
Q
Describe the Alveoli Structure
A
- Alveolar Ducts
- Alveolar Sac
- Alveolar Pores
5
Q
Describe the Alveolar Cells Structure
A
- Collagen Fibril
- Elastic Fibers
- Basal Lamina
- Macrophage
- Type 1
- Type 2
- Fibroblast
6
Q
Describe what happens at the capillary and alveolar membrane
A
- Alveolus
- Alveolar Membrane
- Capillary
- Deoxygenated blood into capillaries
- Oxygenated blood out of capillaries
7
Q
How many zones do the ventilation zones consist of?
A
- 0-23
8
Q
What zones does the conducting zone consist of?
A
- 0-16
9
Q
What components of the pulmonary system make up the conducting zones?
A
- Trachea: 0
- Primary Bronchus: 1
- Bronchus: 2 & 3
- Bronchi: 4 - 10
- Bronchioles: 11 - 16
10
Q
What components of the pulmonary system make up the transitional and respiratory zones?
A
- Respiratory Bronchioles: 17, 18, 19
- Alveolar Ducts: 20, 21, 22
- Alveolar Sacs: 23
11
Q
What does Fick’s Law of Diffusion govern?
A
- Gas Diffusion across a fluid membrane
12
Q
What is the equation for VE?
A
- VE = breathing rate x tidal volume
13
Q
How can VE be increased?
A
Increase
- breathing rate
or
- breathing depth
or
- both
14
Q
How high does the breathing rate increase in a healthy young adult during strenuous exercise? what about for elite endurance athletes?
A
Young Adult
- 35-40 breaths/min
Endurance Athlete
- 60-70 breaths/min
15
Q
What % of vital capacity does tidal volume rarely exceed for trained and untrained individuals?
A
- 60%
16
Q
Explain how gas diffuses through a sheet of tissue.
A
At a rate
- directly proportional to tissue area, a diffusion constant, and pressure differential of the gas on each side of the membrane
- Inversely proportional to tissue thickness
17
Q
What does the pressure differential between air in the lungs and lung-chest wall interface cause?
A
- Lungs to adhere to the chest wall
- Follow its every movement
18
Q
What is minute ventilation?
A
- Volume of air breathed each minute
19
Q
Define Anatomical Dead Space
A
- Air in each breath that does NOT enter alveoli
20
Q
What does anatomical dead space not participate in?
A
- Gaseous exchange with blood
21
Q
What is the approximate volume of anatomic dead space?
A
- 150-200mL
22
Q
Define Alveolar Ventilation
A
- Portion of inspired air that reaches the alveoli
23
Q
What does alveolar ventilation participate in?
A
- Gas exchange
24
Q
What determines the gaseous concentration at the alveolar-capillary membrane?
A
- Alveolar Ventilation
25
What is the approximate range of alveolar ventilation at rest?
- 350mL
26
What enters into and mixes with existing alveolar air at rest?
- 350mL of inspired Tidal Volume
27
What are the typical pulmonary ventilation values during rest?
Breathing Rate (breaths/min)
- 12
Tidal Volume (L/min)
- 0.5
Pulmonary Ventilation (L/min)
- 6
28
What are the typical pulmonary ventilation values during moderate exercise?
Breathing Rate (breaths/min)
- 30
Tidal Volume (L/min)
- 2.5
Pulmonary Ventilation (L/min)
- 75
29
What are the typical pulmonary ventilation values during intense exercise?
Breathing Rate (breaths/min)
- 50
Tidal Volume (L/min)
- 3.0
Pulmonary Ventilation (L/min)
- 150
30
Define the Ventilation-Perfusion (V-P) Ratio
- The ratio of alveolar ventilation to pulmonary blood flow
31
How much air ventilates alveoli each min at rest?
- 4.2L
32
How much blood flows through pulmonary capillaries each minute at rest?
- 5L
33
What is the average V-P ratio? What does it mean?
Average
- 0.84
Mean
- 0.84L alveolar ventilation matches 1L of pulmonary blood flow
34
What is the average concentration of gases in ambient air?
O2
- 20.93%
N2
- 79.04%
CO2
- 0.03%
35
What does the body's supply of oxygen depend on?
- Concentration of Gases in Ambient Air
- Partial Pressure of Gases in Ambient Air
36
Define Partial Pressure
- Molecules of each specific gas in a mixture of gases exert their own partial pressure
37
What is the equation for partial pressure?
% concentration of a specific gas / total pressure of gas mixture
38
What is the partial pressure of Oxygen in dry ambient air at sea level?
20.93% of 760mmHg
- 159mmHg
39
What is the partial pressure of Carbon Dioxide in dry ambient air at sea level?
0.03% of 760mmHg
- 0.2mmHg
40
What is the partial pressure of Nitrogen in dry ambient air at sea level?
79.04% of 760mmHg
- 600mmHg
41
What happens to Tracheal Air?
- Completely saturates with water vapor as it enters nasal cavities, mouth, and down respiratory tract
42
What is the result of the humidification of the tracheal air?
- Effective PO2 in tracheal air decreases by 10mmHg from ambient value
- From 159mmHg to 149mmHg
43
What kind of effect does humidification exert on Pco2? Why?
What
- Negligible
Why
- Little contribution to inspired air
44
How does alveolar air composition differ from incoming breath of moist ambient air?
- CO2 continually enters alveoli from blood
- O2 continually enters blood from the alveoli
45
What are the values of alveolar air?
O2
- 14.5%
CO2
- 5.5%
N2
- 80%
46
What are the average pressures exerted by O2 and CO2 against the alveolar side of the alveolar-capillary membrane?
PO2
- 103mmHg
PCO2
- 39mmHg
47
Define Henry's Law
- Mass of a gas that dissolves in a fluid at a given temperature varies in direct proportion to pressure of the gas over the liquid
48
What two factors govern the rate of gas diffusion into a fluid?
- Pressure differential between gas above the fluid and gas dissolved in the fluid
- Solubility of gas in the fluid
49
What is the equation for the Quantity of gas (mL/dL)?
Quantity of gas (mL/dL) = solubility coefficient x (gas partial pressure/total barometric pressure)
50
How does O2 travel?
From higher to lower pressure
- as it dissolves and diffuses through the alveolar membrane into blood
51
What causes a net diffusion of CO2 from the blood to the lungs?
- Higher pressure in returning venous blood than in alveoli
52
What happens to Nitrogen in alveolar-capillary gas?
- Remains Essentially unchanged
53
How quickly does alveolar gas-blood equilibrium change?
- 0.25s
54
What is the PO2 in fluid outside a muscle cell at rest?
- 40mmHg
55
What is the PCO2 in intracellular fluid at rest?
- 46mmHg
56
What does the PO2 in active fall to during vigorous exercise?
towards
- 0mmHg
57
What does the PCO2 in active muscle approach during vigorous exercise?
- 90mmHg
58
What establishes the diffusion gradient?
- Pressure differences between gases in plasma and tissues
59
Which direction does O2 and CO2 travel in diffusion?
O2
- From blood towards cells
CO2
- From cells towards blood
60
What does blood do after CO2 flows from the cells into it?
- passes into the venous circuit for return to the heart and delivery to the lungs
61
What does Alveolar Ventilation couple with? Why?
Couples With
- Metabolic demand
Why?
- maintain constant alveolar gas composition
62
What happens to alveolar gas concentration during strenuous activity?
Maintains
- Increases VO2 and VCO2 output
- 25x resting values
63
What two ways does blood transport oxygen?
- Dissolved in fluid portion of blood
- In loose combination with hemoglobin
64
What is hemoglobin?
- Iron-containing globular protein pigment within red blood cells
65
What keeps oxygen's concentration low within body fluids?
- Oxygen's relative insolubility in water
66
What are the functions of O2 transported in physical solutions?
- Establishes Po2 of plasma and tissue fluids
- Helps to regulate breathing, particularly at altitude
- Determined O2 loading of hemoglobin in lungs and release in tissues
67
How much O2 does hemoglobin carry compared to plasma?
- 65-70 times more
68
How many iron atoms are in hemoglobin molecules?
- 4
69
How many Oxygen molecules can each of the Iron atoms in hemoglobin loosely bind to?
- 1 per Iron molecule
70
What dictates the oxygenation of hemoglobin to oxyhemoglobin?
- Partial pressure of O2
71
Describe the structure of the hemoglobin molecule
Protein Globin composed of 4 subunit polypeptide chains:
- Beta Polypeptide Chains
- Alpha Polypetide Chains
- Iron Atom
- O2
72
What does a single polypeptide contain?
- Single heme groups with a single iron atom
- Iron atom acts as oxygen magnet
73
What is the oxygen-carrying capacity of hemoglobin?
Men = 15g Hb/dL blood
Women = 14g Hb/dL blood
74
How much O2 can each gram of Hb combine with?
- 1.34mL of O2
75
At full O2 saturation and normal Hb levels, how much O2 does Hb carry per dL of blood?
- 20mL
76
What is the equation for Blood's O2 Capacity?
Blood O2 Capacity = Hb x Hb O2 Capacity
77
Draw the Oxyhemoglobin Dissociation Curve
- Check with Notes
78
What is the oxygen transport cascade?
- Changing partial pressures of O2 as it moves from ambient air at sea level to the mitochondria of maximally active muscle tissue
79
Draw the Oxygen Transport Cascade
- Check with Notes
80
Explain the Bohr Effect
- Any increase in plasma acidity and temperature causes the oxyhemoglobin dissociation curve to shift downward and to the right
81
When does the reduced effectiveness of hemoglobin to hold O2 occur?
PO2 range of:
- 20-50mmHg
82
What alters hemoglobin's molecular structure to decrease its O2-binding affinity?
- [H+]
- CO2
83
When does the Bohr effect predominate?
- during intense exercise
- As more O2 releases to tissue
84
Why does more O2 release to tissue during intense exercise?
Associated increases in:
- Metabolic Heat
- CO2
- ACididty
(from blood lactate accumulation)
85
What does Po2 average in cell fluid during rest?
- 40mmHg
86
What does an average Po2 of 40mmHg make dissolved O2 from plasma do?
- diffuse across capillary membranes through tissue fluid into cells
87
What causes Hb to lower its O2 saturation level?
- Reduced plasma PO2 below PO2 in red blood cells
88
How does O2 release out of blood cells?
- Through the capillary membrane into tissues
89
What does the a-vO2 difference describe?
- The difference between the oxygen content of arterial blood and mixed-venous blood
90
What does the a-vO2 difference average?
- 4-5mL O2/dL blood
91
Can O2 release from Hb without any increase in local tissue blood flow?
- Yes
92
By how much does O2 released to muscles increase during vigorous exercise?
- by 3 times resting levels
93
What does active muscle's uncompromising capacity to use available O2 in its large blood flow support?
- O2 supply, not muscle O2 use, limits aerobic exercise capacity.
94
How does a red blood cell get its energy? Why?
How
- Anaerobic Glycolysis
Why
- Contains no mitochondria
95
What does the red blood cell produce when it makes energy from anaerobic glycolysis?
- compound 2,3-diphosphoglycerate (2,3-DPG)
96
What does 2,3-DPG bind to?
- subunits of Hb
97
What does 2,3-DPG binding with subunits of Hb do? what does this cause?
Reduces Hb's affinity for O2
- greater O2 release to tissues for given decrease in PO2
98
When does increased levels of red blood cell 2,3-DPG occur?
- Cardiopulmonary disorders
- Those who live at high altitude to facilitate O2 release
99
When does 2,3-DPG aid in O2 transfer to active muscles?
- During Strenuous exercise
100
What provides the only means for escape for CO2 once it forms?
- Diffusion and subsequent transport in venous blood through lungs
101
What three ways does blood carry CO2?
- In physical solution in plasma
- Combined with hemoglobin within red blood cells
- Plasma Bicarbonate
102
Explain and draw the pathway of CO2 leaving the body
- Check with Notes
103
What does CO2 in solution form when combined with water?
- Carbonic Acid
- CO2 + H2O ---- H2CO3
104
What happens once carbonic acid forms in tissues?
- Most ionizes into hydrogen ions [H+] and bicarbonate ions [HCO3-]
105
What % of CO2 exists in plasma bicarbonate?
- 60-80%
106
What enzyme catalyzes the bicarbonate buffer system?
- Carbonic Anhydrase
107
At the tissue level, when do carbamino compounds form?
- When CO2 reacts directly with the amino acid molecules of blood protein
108
What part of the Hb forms a carbamino compound?
- Globin Portion of Hb
109
How much CO2 does Globin carry?
- 20% of the body's CO2
110
Describe the Haldane Effect
- A decrease in plasma Pco2 in the lungs reverses carbamino formation
111
What does a decrease in plasma Pco2 in the lungs that reverses carbamino formation do? When does this happen?
Causes
- CO2 moves into the solution and enter the alveoli
When
- Oxygenation of hemoglobin reduces its ability to bind CO2
112
What does the Haldane Effect describe?
- The ability of hemoglobin to carry increased amounts of CO2 in the deoxygenated state as opposed to the oxygenated state
113
What does buffering mean in the pulmonary system?
- Chemical and physiologic mechanisms to minimize changes in H+ concentration
114
What does the pH of body fluids range from?
- As low as 1.0 to 7.45
115
Define Alkalosis
- Decrease in H+ Concentration
116
Define Acidosis
- Increase in H+ concentration
117
What mechanisms regulate internal pH?
- Chemical Buffers
- Pulmonary Ventilation
- Renal Function
118
What do chemical buffers consist of?
- Weak acid and salt of that acid
119
What does the buffering reaction produce when H+ concentrations remain elevated?
- Weak Acid
120
What does the buffering reaction do when H+ concentrations decrease?
- Releases H+
121
What are the Chemical Buffers?
- Bicarbonate Buffer
- Phosphate Buffer
- Protein Buffer
122
What does the Bicarbonate Buffer system consist of?
- Carbonic Acid (H2CO3) and Sodium Bicarbonate (NaHCO3)
123
What happens during bicarbonate buffering?
- Hydrochloric Acid (HCL) converts to carbonic acid by combining with sodium bicarbonate
124
What is the chemical equation for the bicarbonate buffer system?
HCL + NaHCO3 --> NaCl + H2CO3 <---> H+ + HCO3-
125
What does the buffering of HCL produce?
- small decrease in pH
126
What does sodium bicarbonate have with lactic acid? What does it form?
Strong buffering action
- forms sodium lactate and carbonic acid
127
What does additional H+ increase from carbonic acid dissociation cause?
- Dissociation reaction to move to the opposite direction to release CO2 into solutions
128
What stimulates VE? What does it do?
An increase in plasma CO2 and H+ concentration
- eliminates excess CO2
129
When does the body produce greater amounts of hydrogen ions [H+]?
During Exercise
130
What does an increase in H+ ions during exercise do?
- Decreases performance
131
How does the sodium bicarbonate buffer system protect exercise performance?
- Buffers acids by binding with them
- Can prolong energy metabolism in the muscle cells during exercise
132
What does the buffering of Hydrogen Ions [H+] during exercise by the sodium bicarbonate buffer system do?
- prolongs energy metabolism in muscle cells
- Translates to more sustained power output
133
What does the increase in extracellular fluid and plasma H+ concentration stimulate?
- Respiratory center to increase alveolar ventilation
- Reduce alveolar Pco2 and cause CO2 blow off
134
What does reduced CO2 in plasma accelerate?
- Recombination of H+ and HCO3-
- Lowers H+ concentration in plasma
135
Describe the Renal Buffer system
- Renal tubules regulate acidity
- Complex chemical reactions secrete ammonia
- H+ into urine & reabsorb alkali, chlorine, and bicarbonate
136
What complex mechanisms adjust breathing rate and depth to the body's metabolic needs?
- Intrinsic Neural Circuits
- Gaseous and Chemical States
137
Describe the Intricate Neural Circuits that adjust breathing rate and depth to the body's metabolic needs
- Relay information from higher brain centers, lungs, and other bodily "sensor" to coordinate ventilatory control
138
Describe how Gaseous and chemical states adjust breathing rate and depth to body's metabolic needs
- Blood bathes the medulla and aortic and carotid artery chemoreceptors
139
What do control mechanisms maintain for pulmonary ventilation?
- relatively constant alveolar gas pressures throughout a broad range of exercise intensities
140
When does the blood's chemical state exert the greatest control on pulmonary ventilation?
- At Rest
141
What do variations in arterial Po2, Pco2, pH, and temperature activate?
- Sensitive neural units in the medulla and arterial system
142
What does the activation of sensitive neural units in the medulla and arterial system from variations in arterial Po2, Pco2, pH, and temperature do?
- Adjust ventilation and maintain arterial blood chemistry within narrow limits
143
What control's the sensitivity to reduced O2 pressure?
- Peripheral chemoreceptors
144
What monitors the state of arterial blood just before it perfuses brain tissues?
- Carotid bodies
145
What does decreased arterial Po2 increase? how?
What
- Alveolar Ventilation
How
- Stimulation of aortic and carotid chemoreceptors
146
What do aortic and carotid chemoreceptors protect against?
- Reduced oxygen pressure in inspired air
147
When do aortic and carotid chemoreceptors become increasingly important?
- In lung disease
- In High-altitude exposure
148
What do increases in temperature, acidity, CO2, and potassium concentrations do?
- Read by peripheral chemoreceptors that stimulate ventilation during exercise
149
What does peripheral chemoreceptors defend against?
- Arterial hypoxia in pulmonary disease
- Ascent to higher altitudes
150
What do peripheral chemoreceptors help with?
- Regulate exercise hyperpnea
151
What provides an important respiratory stimulus at rest?
- Pco2 in arterial plasma
152
What can small increases in Pco2 in inspired air trigger?
- Large increases in minute ventilation
153
What does plasma acidity vary with?
- blood's CO2 content
154
What does variations in plasma acidity exert strong command over?
- Ventilation
155
What does a fall in blood pH signal? What does it reflect?
Signals
- Acidosis
Reflects
- CO2 retention
- Carbonic Acid Formation
156
What happens as arterial pH declines and H+ accumulates?
- inspiratory activity increases to eliminate CO2
- Reduce arterial levels of carbonic acid
157
What makes pH regulation progressively more difficult?
- Increased H+ concentration from CO2 production and lactate formation during strenuous exercise
158
When does acid-base regulation become difficult?
- Repeated, brief bouts of all-out exercise that elevates blood lactate values > 30mM
159
When humans tolerate pronounced disturbances in acid-base balance during maximal exercise?
- Temporarily
160
What can a plasma pH <7.0 cause?
- Nausea
- Headache
- Dizziness
