MAPII Final Flashcards
(217 cards)
1
Q
What are the 5 major functions of respiration?
A
- Pulmonary Ventilation
- External Respiration
- Transport of respiratory gasses
- Internal Respiration
- Regulation of ventilation/respiration
2
Q
What are the 5 major functions of respiration?
A
- Pulmonary Ventilation
- External Respiration
- Transport of respiratory gasses
- Internal Respiration
- Regulation of ventilation/respiration
3
Q
How many lobes does the right lobe consist of? Left?
A
Right = 3 Left = 2
4
Q
The lungs occupy all of thoracic cavity except the
A
mediastinum
5
Q
What tissue type are the lungs made of and why?
A
elastic connective tissue, helps reduce work of breathing.
6
Q
Where do the lungs receive their blood supply from? What is the route of the artery? What percentage of the cardiac output is taken to the heart?
A
Bronchial Arteries - off aorta, enter lungs through hilum. 1-2% of cardiac output goes through here.
7
Q
What removes the blood supply form the lungs? What is the route of the vein? What is the significance of this route?
A
Pulmonary Veins - carry deoxygenated blood back to left atrium
8
Q
What is the function of the parasympathetic nervous system on respiration?
A
- Constriction of air tubes
- ACH released –> smooth muscle contraction
- Increased airway resistance
- Slows and reduces volume of airflow.
9
Q
What is the function of the sympathetic nervous system on respiration?
A
- Dilation of air tubes
- Weak Direct control
- Strong effect by Epi and NE released in blood from adrenal medulla
- ->smooth muscle relaxation
- Reduces airway resistance –> enhances flow
10
Q
Intrapleural pressure is ___ so is (negative/positive) pressure compared to atmospheric?
A
Intrapleural pressure: 756mmHg
Atmospheric 760mmHg
-4mmHg: Negative pressure difference
11
Q
The airways are broken up in what to tracts?
A
Upper Respiratory Tract
Lower Respiratory Tract
12
Q
What is the start and end of the Upper Respiratory Tract? What consists of the upper respiratory tract?
A
From nasal and oral orifices –> false vocal cords in larynx
Nose
Nasal Cavity
Pharynx (naso, oro, laryngo)
Larynx
13
Q
What is the start and end of the Lower Respiratory Tract?
A
From level of true vocal cords to alveoli
14
Q
What is the Lower Respiratory Tract divided into? What volume are the zones?
A
Conducting Zone - 150mL
Respiratory Zone
- 2.5L at Rest
- Up to 4-6 w/ max inspiration
15
Q
What makes up the conducting zone?
A
Trachea R + L Primary Bronchi Secondary Bronchi Tertiary Bronchi Bronchioles Terminal Bronchios
16
Q
T/F: No gas exchange is done in the conducting zone.
A
True
17
Q
At what level does the Trachea bifurfacte and what type of cells is it made up of? What is their function?
A
Bifurcates @ T7. Made up of columnar cells that secrete mucus to catch stuff on way down. The cilia move it.
18
Q
Is the right of left primary bronchi more vertical? What is the clinical significance of this?
A
Right is more vertical than Left. Right is more common site for inhaled foreign body.
19
Q
How many secondary-lobar bronchi are there on the right and left?
A
3 on the Right
2 on the left
20
Q
How many order of branching do the tertiary-segmental bronchi have?
A
approx 23
21
Q
In a normal patient, do smaller or larger bronchioles provide greats amount of resistance to airflow? Disease conditions?
A
Normal: larger bronchioles near trachea provide greatest amount of resistance to airflow.
Disease Conditions: smaller bronchioles provide greatest resistance to airflow.
22
Q
Roughly what diameter are Terminal Bronchioles? Does gas exchange occur here?
A
23
Q
What structures does the respiratory zone consist of?
A
Respiratory bronchioles
Alvelor duct
Alveolar sacs
Alveoli
24
Q
What type of cells are the walls of alveoli made up of? What are these cells surrounded by? What are the external surface of the alveolar walls covered by?
A
Walls are type 1 cells: single layer of squamous epithelial cells.
Surrounded by basement membrane.
Ext. surface covered by web of capillaries.
25
What makes up the Respiratory Membrane?
Alveolar walls + Capillary Walls + fused basement membrane.
26
At rest perminute, what volume of O2 leave alveoli to blood, and what volume of CO2 diffuse from blood to gas in alveoli?
@ rest / min:
- 250ml of O2 leave alveoli to blood
- 200ml of CO2 diffuse from blood to gas in alveoli
27
What is the function of Type 2 cells?
secrete surfactant
28
What do pores in the alevoli allow for?
nutrient transport
29
How does pulmonary edema affect respiration?
Effects diffusion (rate of diffusion through tissue water is the limiting factor in transport)
30
What is anatomical dead space? What is physiological dead space and how does it compare?
Dead Space: No gas exchange
Anatomical: Conducting Zone + Upper Airway: vol of all space of respiratory system other than alveoli and closely related gas exchange areas.
Physiological: Alveolar dead space (includes non functional alveoli)
Health Individual: anatomical = physiological
31
How is pulmonary ventilation defined?
movement of air into and out of lungs = breathing
32
What percentage of total body expenditure is required for pulmonary ventilation? What is the clinical significance of this?
3-5%
this percentage will increase with exercise so can train inspiritory muscles to make efficient.
33
During quiet inspiration, what is the primary muscle used and how does it affect thoracic volume?
Primary = contraction of diaphragm from dome shape to flattened.
Increases thoracic volume in superior to inferior dimension.
34
During forced inspiration what muscles are used and how do they affect thoracic volume?
Elevation of the ribs:
-External intercostals: lift rib cage and pull sternum superiorly. Lateral and Anterior-Posterior expansion of thoracic cavity.
SCM, Scalenes, Anterior Serratus, Pec Minor, Errector Spinae
35
During quiet expiration, what muscles are used and how do they affect thoracic volume?
relaxation of diaphragm from flattened to dome shape.
Rib cage resume resting position, lungs recoil. Decrease thoracic and intrapulmonary vol compression alveoli.
36
During forced expiration, what muses are used?
additional muscles are recruited for depression of ribs with increased respiratory demands/forced expriation
internal intercostals and rectus abdominus
37
Respiratory pressure is always described relative to
atmospheric pressure
38
What does boyle's law indicate?
at constant temp, pressure of gas varies inversely volume
P1V1 = P2V2
Increase in volume --> decrease in pressure
39
What is atmospheric pressure Patm?
760mmHg @ sea level
40
During inspiration, Palv drops to ___ H2O. What does this allow?
~-1cm H2O
enough to allow 500ml of air to be pulled into the lungs in ~2 seconds
41
During expiration: Palv raises to __ H2O. What does this allow?
~1cm H2O
drives air out of alveoli in ~2-3 seconds
42
What is intrapleural cavity pressure in relation to Patm? Why is it negative?
-4mmHg
You have 2 forces trying to pull lungs away from thorax wall which would cause the lung to collapse.
1. Lungs natural recoil tendency
2. Surface tension of alveolar fluid
Opposed by elasticity of chest wall and maintaining pleural fluid adhesive force.
43
What is transpulmonry pressure and why is it important?
Palv - Pip = difference between alveolar pressure and pleural pressure.
Fxn: to keep air spaces of lungs open.
44
What is atelectasis?
lung collapse or part (alveoli)
45
What is pneumothroax?
air in intrapleural space.
46
What is lung compmliance and what determines it?
measure of change in lung volume that happens with a given change in transpulmonary pressure.
Determined by:
1. distensibility - elastic forces of lung tissue
2. Alveolar Surface Tension - surfactant (decreases)
47
In smaller alveoli, what is the greater alveolar pressure caused by?
surface tension (decreased by surfactant)
48
What is surfactant made up of and what function does it serve?
Produced by Type II cells, made of phospholipids, proteins, and ions.
Reduces surface tension which reduces effort required by respiratory muscles to expand lungs.
49
What affect does interstitial lung disease have on distensibility?
reduces it
50
Does an alvoli collapse due to increase or decrease in distensibility.
decreased distensibility
51
What is TV? About how many ml is it?
Tidal Volume - Amount of air inhaled/exhaled w/ breathing under resting conditions. ~500ml
52
What is IRV?
Inspiratory Reserve Volume - Amount of air that can be forcefully inhaled after normal TV exhalation
53
What is ERV?
Expiratory Reserve Volume - Amount of air that can be forefully exhaled after normal tidal volume exhalation.
54
What is RV?
Residual Volume - Amount of air remaining in lungs after forced exhalation.
55
What is TLC?
Total Lung Capacity - Max amount of air contained in the lungs after max inspiritory effort.
TLC = TV + IRV + ERV + RV
56
What is VC?
Vital Capacity - max amount of air that can be expired after max inspiritory effort.
VC = TV + IRV + ERV
57
What is IC?
Inspiratory Capacity - max amount of air that can be inspired after normal expiration.
IC = TV + IRV
58
What is FRC?
Functional Residual Capacity - Volume of air remaining in the lungs after normal TV expiration.
59
What is FVC?
Forced Vital Capaity - Max vol of air exhaled during forced maneuver.
60
What is FEV1?
Forced expired volume in 1 second. Measure of how quickly lungs emptied.
61
How do you calculate VA?
VA = Frequency * (VT - VD)
62
How do you calculate VA?
VA = Frequency * (VT - VD)
63
How many lobes does the right lobe consist of? Left?
```
Right = 3
Left = 2
```
64
The lungs occupy all of thoracic cavity except the
mediastinum
65
What tissue type are the lungs made of and why?
elastic connective tissue, helps reduce work of breathing.
66
Where do the lungs receive their blood supply from? What is the route of the artery? What percentage of the cardiac output is taken to the heart?
Bronchial Arteries - off aorta, enter lungs through hilum. 1-2% of cardiac output goes through here.
67
What removes the blood supply form the lungs? What is the route of the vein? What is the significance of this route?
Pulmonary Veins - carry deoxygenated blood back to left atrium
68
What is the function of the parasympathetic nervous system on respiration?
- Constriction of air tubes
- ACH released --> smooth muscle contraction
- Increased airway resistance
- Slows and reduces volume of airflow.
69
What is the function of the sympathetic nervous system on respiration?
- Dilation of air tubes
- Weak Direct control
- Strong effect by Epi and NE released in blood from adrenal medulla
- ->smooth muscle relaxation
- Reduces airway resistance --> enhances flow
70
Intrapleural pressure is ___ so is (negative/positive) pressure compared to atmospheric?
Intrapleural pressure: 756mmHg
Atmospheric 760mmHg
-4mmHg: Negative pressure difference
71
The airways are broken up in what to tracts?
Upper Respiratory Tract
| Lower Respiratory Tract
72
What is the start and end of the Upper Respiratory Tract? What consists of the upper respiratory tract?
From nasal and oral orifices --> false vocal cords in larynx
Nose
Nasal Cavity
Pharynx (naso, oro, laryngo)
Larynx
73
Net rate of diffusion of a dissolved gas through fluid is determinant on
1. Pressure difference
2. Solubility of gas in fluid
3. Cross Sectional Area of fluid
4. Distance gas must diffuse
5. Molecular weight of gas (lighter = faster)
6. Temperature of fluid (constant in this case)
74
What is the Lower Respiratory Tract divided into? What volume are the zones?
Conducting Zone - 150mL
Respiratory Zone
- 2.5L at Rest
- Up to 4-6 w/ max inspiration
75
What makes up the conducting zone?
```
Trachea
R + L Primary Bronchi
Secondary Bronchi
Tertiary Bronchi
Bronchioles
Terminal Bronchios
```
76
T/F: No gas exchange is done in the conducting zone.
True
77
At what level does the Trachea bifurfacte and what type of cells is it made up of? What is their function?
Bifurcates @ T7. Made up of columnar cells that secrete mucus to catch stuff on way down. The cilia move it.
78
Is the right of left primary bronchi more vertical? What is the clinical significance of this?
Right is more vertical than Left. Right is more common site for inhaled foreign body.
79
How many secondary-lobar bronchi are there on the right and left?
3 on the Right
| 2 on the left
80
How many order of branching do the tertiary-segmental bronchi have?
approx 23
81
In a normal patient, do smaller or larger bronchioles provide greats amount of resistance to airflow? Disease conditions?
Normal: larger bronchioles near trachea provide greatest amount of resistance to airflow.
Disease Conditions: smaller bronchioles provide greatest resistance to airflow.
82
Roughly what diameter are Terminal Bronchioles? Does gas exchange occur here?
83
What structures does the respiratory zone consist of?
Respiratory bronchioles
Alvelor duct
Alveolar sacs
Alveoli
84
What type of cells are the walls of alveoli made up of? What are these cells surrounded by? What are the external surface of the alveolar walls covered by?
Walls are type 1 cells: single layer of squamous epithelial cells.
Surrounded by basement membrane.
Ext. surface covered by web of capillaries.
85
What makes up the Respiratory Membrane?
Alveolar walls + Capillary Walls + fused basement membrane.
86
At rest perminute, what volume of O2 leave alveoli to blood, and what volume of CO2 diffuse from blood to gas in alveoli?
@ rest / min:
- 250ml of O2 leave alveoli to blood
- 200ml of CO2 diffuse from blood to gas in alveoli
87
What is the function of Type 2 cells?
secrete surfactant
88
What do pores in the alevoli allow for?
nutrient transport
89
What is the PO2 and PCO2 for:
| Exhaled air?
```
PO2 = 120
PCO2 = 27
```
90
What is anatomical dead space? What is physiological dead space and how does it compare?
Dead Space: No gas exchange
Anatomical: Conducting Zone + Upper Airway: vol of all space of respiratory system other than alveoli and closely related gas exchange areas.
Physiological: Alveolar dead space (includes non functional alveoli)
Health Individual: anatomical = physiological
91
How is pulmonary ventilation defined?
movement of air into and out of lungs = breathing
92
What percentage of total body expenditure is required for pulmonary ventilation? What is the clinical significance of this?
3-5%
this percentage will increase with exercise so can train inspiritory muscles to make efficient.
93
During quiet inspiration, what is the primary muscle used and how does it affect thoracic volume?
Primary = contraction of diaphragm from dome shape to flattened.
Increases thoracic volume in superior to inferior dimension.
94
During forced inspiration what muscles are used and how do they affect thoracic volume?
Elevation of the ribs:
-External intercostals: lift rib cage and pull sternum superiorly. Lateral and Anterior-Posterior expansion of thoracic cavity.
SCM, Scalenes, Anterior Serratus, Pec Minor, Errector Spinae
95
What is the PO2 at:
- ISF surrounding Tissue
- Tissue
- Bronchial Arteries
ISF Surrounding Tissue = 40mmHg
Tissue = 5-40mmHg (avg. 23)
-Determined by rate of O2 transport to tissue and rate @ which O2 used.
Bronchial Arteries = 95mmHg
-Supply deep tissues of lungs and don't come into contact w/ lung air and then returned by pulm veins to L atrium. 2% of blood flow that never comes into contact with alveoli.
96
During forced expiration, what muses are used?
additional muscles are recruited for depression of ribs with increased respiratory demands/forced expriation
internal intercostals and rectus abdominus
97
HgB transports what percentage of O2 from lungs to tissues? How much additional O2 transport does this allow?
How is the rest carried?
97% - allows transport of 30-100x amount of O2 than if O2 was just transported in dissolved gas in water of blood.
3% is carried in H2O of plasma and RBCs
98
What does boyle's law indicate?
at constant temp, pressure of gas varies inversely volume
P1V1 = P2V2
Increase in volume --> decrease in pressure
99
What is atmospheric pressure Patm?
760mmHg @ sea level
100
During inspiration, Palv drops to ___ H2O. What does this allow?
~-1cm H2O
enough to allow 500ml of air to be pulled into the lungs in ~2 seconds
101
During expiration: Palv raises to __ H2O. What does this allow?
~1cm H2O
drives air out of alveoli in ~2-3 seconds
102
What is intrapleural cavity pressure in relation to Patm? Why is it negative?
-4mmHg
You have 2 forces trying to pull lungs away from thorax wall which would cause the lung to collapse.
1. Lungs natural recoil tendency
2. Surface tension of alveolar fluid
Opposed by elasticity of chest wall and maintaining pleural fluid adhesive force.
103
What is transpulmonry pressure and why is it important?
Palv - Pip = difference between alveolar pressure and pleural pressure.
Fxn: to keep air spaces of lungs open.
104
What is atelectasis?
lung collapse or part (alveoli)
105
What is pneumothroax?
air in intrapleural space.
106
What is lung compmliance and what determines it?
measure of change in lung volume that happens with a given change in transpulmonary pressure.
Determined by:
1. distensibility - elastic forces of lung tissue
2. Alveolar Surface Tension - surfactant (decreases)
107
What is the Bohr effect?
Weakening of Hgb-O2 bond
O2 unloaded where it's most needed.
108
What is surfactant made up of and what function does it serve?
Produced by Type II cells, made of phospholipids, proteins, and ions.
Reduces surface tension which reduces effort required by respiratory muscles to expand lungs.
109
What affect does interstitial lung disease have on distensibility?
reduces it
110
Does an alvoli collapse due to increase or decrease in distensibility.
decreased distensibility
111
What is TV? About how many ml is it?
Tidal Volume - Amount of air inhaled/exhaled w/ breathing under resting conditions. ~500ml
112
What is IRV?
Inspiratory Reserve Volume - Amount of air that can be forcefully inhaled after normal TV exhalation
113
What is ERV?
Expiratory Reserve Volume - Amount of air that can be forefully exhaled after normal tidal volume exhalation.
114
What is RV?
Residual Volume - Amount of air remaining in lungs after forced exhalation.
115
What is TLC?
Total Lung Capacity - Max amount of air contained in the lungs after max inspiritory effort.
TLC = TV + IRV + ERV + RV
116
What is VC?
Vital Capacity - max amount of air that can be expired after max inspiritory effort.
VC = TV + IRV + ERV
117
What is IC?
Inspiratory Capacity - max amount of air that can be inspired after normal expiration.
IC = TV + IRV
118
What is FRC?
Functional Residual Capacity - Volume of air remaining in the lungs after normal TV expiration.
119
What is FVC?
Forced Vital Capaity - Max vol of air exhaled during forced maneuver.
120
What is FEV1?
Forced expired volume in 1 second. Measure of how quickly lungs emptied.
121
Which diffuses faster, CO2 or O2? Why?
CO2
- More soluable (20% more b/c of molecular attraction to water)
- Less pressure difference needed to cause CO2 diffusion than O2 diffusion
--remember at same partial pressure, CO2 diffuses almost 20x faster.
122
How do you calculate VA?
VA = Frequency * (VT - VD)
123
What makes up the respiratory membrane?
Alevolar + Capillary Walls + Fused Basement Membrane
124
Roughly what volume of blood is in the lungs?
~450ml
125
Roughly what volume of blood is in the pulmonary capillaries?
70ml
126
Which alveoli get the blood?
The ones with the best oxygenation.
127
What affect does low oxygen concentration have on capillaries? Why?
constriction
(opposite to systemic capillary reaction to low O2)
Purpose is to make sure blood goes to alvoli with high O2
128
What happens if Palv > Ppc?
capillaries close and no blood flow
129
With exercise, what happens blood volume to the lung? Capillaries?
Blood volume increased 4-7 fold.
Increase # of open capillaries and they distend and therefore increase rate of low.
Pulmonary pressure increases but minimally.
130
How do you calculate the partial pressure of a specific gas?
Ex.
O2 = 20.84%
Partial Pressure = Atmospheric Pressure * percentage of molecule in gas
PO2 = 760mmHg * 20.84% = 159mmHg
131
The rate of diffusion of a gas is directly related to its
partial pressure
132
What is pressure of a gas in fluid determined by?
Concentration ad Solubility coefficient of gas
133
Does O2 or CO2 have a higher Solubility coefficient? Why? What does the mean?
O2 = 0.024
CO2 = 0.57
High # = more Soluble
CO2 in 20% more solube in liquids than O2 is. Different b/c molecular attraction to water.
134
Net rate of diffusion of a dissolved gas it determinant on
1. Pressure difference
2. Solubility of gas in fluid
3. Cross Sectional Area of fluid
4. Distance gas must diffuse
5. Molecular weight of gas (lighter = faster)
6. Temperature of fluid (constant in this case)
135
What does the diffusion coefficient tell us? How does O2 compare to CO2?
Relative rate of gasses @ same partial pressure will diffuse
```
O2: 1
CO2: 20.3
CO: 0.81
N: 0.53
He: 0.95
```
136
What is the limiting factor in the rate at which a respiratory gas can diffuse through a tissue? What does this mean in terms of the rate of diffusion?
Respiratory gases are soluble in lipids making diffusion across membranes easy. Rate of diffusion through tissue water is the limiting factor.
Therefore rate of diffusion through tissues ~= rate of diffusion through water.
137
What two things control alveolar O2 concentration?
O2 constantly being absorbed from alveoli:
1. Rate of absoprtion by pulmonary capillaries
2. Rate of O2 entry into alveoli via ventilation
138
T/F PO2 in alveoli can never exceed 149mmHg @ seal level if person is breathing normal ATM air.
True: Can't go any higher than humidified air concentration.
139
What happens if Palv > Patm?
lungs collapse.
140
How much of alveolar air is replaced by new air each breath?
1/7
141
What is the PO2 and PCO2 for:
| Atmospheric Air / Inhaled Air
```
PO2 = 160
PCO2 = 0.3
```
142
What is the PO2 and PCO2 for: Humidified Air?
```
PO2 = 150
PCO2 = 0.3
```
143
What is the PO2 and PCO2 for: Alveolar Air?
```
PO2 = 104
PCO2 = 40
```
144
What is the PO2 and PCO2 for: Blood leaving alveolar capillaries?
```
PO2 = 104
PCO2 = 40
```
145
What is the PO2 and PCO2 for: Blood entering tissue capillaries?
```
PO2 = 104
PCO2 = 40
```
146
What is PO2 and PCO2 for:
| INSIDE the tissues
PO2 = 45
147
What is PO2 and PCO2 for:
| Blood leaving tissue capillaries?
```
PO2 = 40
PCO2 = 45
```
148
What is PO2 and PCO2 for:
| Blood entering alveolar capillaries?
```
PO2 = 40
PCO2 = 45
```
149
What is PO2 and PCO2 for:
| Alveoli of lungs?
```
PO2 = 104
PCO2 = 40
```
150
What is the PO2 and PCO2 for:
| Exhaled air?
```
PO2 = 120
PCO2 = 27
```
151
Does diffusion happen slowly or fast through the respiratory membrane?
Fast
- Large surface area w/ small amount of blood spread throughout.
- Small diameter of pulmonary capillaries w/ large blood cell.
152
Diffusion of a gas across the respiritory membrane is affected by:
1. Thickness of membrane
2. Surface area of membrane
3. Diffusion coefficient of gas
4. Pressure different across the membrane
153
How is the respiritory membrane diffusion capacity defined?
by the volume of gas that will diffuse through the membrane each minute, for a partial pressure difference of 1mmHg.
154
What is Va/Q?
What is Optimal?
What is 0?
What is Infinity?
Ventiliation-perfusion ratio
- 4 parts air / 5 parts blood = 0.8
- 0 / 5 blood = 0: not breathing and no gas exchange
- 4 air / 0 blood = infinity: adequate breathing but no blood flow and no gas exchange
155
Where in the length of a capillary does pulmonary diffusion occur at rest?
First 1/3 of capillary length
156
What is the PO2 at:
- ISF surrounding Tissue
- Tissue
- Bronchial Arteries
ISF Surrounding Tissue = 40mmHg
157
How much O2 do cells require to fully support chemical processes needed? What does this mean for us?
Cells require 1-3mmHg to fully support chemical processes needed.
Means there's a reserve that you don't actually need, good for exercise.
158
HgB transports what percentage of O2 from lungs to tissues? How much additional O2 transport does this allow?
How is the rest carried?
97% - allows transport of 30-100x amount of O2 than if O2 was just transported in dissolved gas in water of blood.
3% is carried in H2O of plasma and RBCs
159
What effect does High PO2 have on binding of O2 to HgB? How many ml of O2 are carries to the tissue with what Hgb saturation?
Low PO2?
PO2 High --> O2 binds w/ Hgb
- Lungs/arterial blood = PO2 Hgb: 97%
- 19.4ml O2 carries to tissue
PO2 Low --> O2 released from Hgb
- Tissues = PO2 Hgb: 75%
- Leaves w/ 14.4ml O2
160
How many ml of O2 is left at the tissue for 100ml of blood?
5ml
161
15 grams of Hgb can carry how many ml of O2 in 100ml of blood?
20ml (if 100% saturated)
162
If Interstitial PO2 drops from 40mmHg to 15mmHg, what happens to O2 delivery?
Net delivery needs to be 15mmHg so there will be ~5ml O2 left in 100ml of blood.
3x normal amount of O2 delivered.
163
What affect can an increase of CO by 6-7x normal have on O2 tissue delivery to tissues?
3x normal amount of O2 delivered from HgB + 6-7x normal CO = 20 fold increase of O2 delivery to tissues.
164
Normal O2 delivery requires PO2 to drop to what?
40mmHg.
Hgb released enough O2 at a PO2 of 40mmHg for normal 5ml of O2 to be delivered and sets upper limit on O2 partial pressure.
165
With exercise, what can PO2 in tissue drop to? Is this large or small?
40-15mmHg which is relatively small.
--> very large additional release of O2 from HgB
166
What causes a right shift in O2-HgB dissociation curve?
```
Increase in
Acid (decrease pH)
CO2
Exercise
2,3-BPG
Altitude
Temperature
```
167
What causes a left shift in O2-HgB dissociation curve?
```
Decrease in
Acid (increase pH)
CO2
Exercise
2,3-BPG
Altitude
Temperature
```
168
What is the Bohr effect?
Weakening of Hgb-O2 bond
O2 unloaded where it's most needed.
169
What is the limiting factor for cellular reactions?
ADP - not that you run out of O2
PO2 > 1mmHg is good
170
How does diffusion limit cellular reactions?
Doesn't cause major effects, need a pathology to really see problem
171
How does blood flow limit cellular reactions?
If cut off then won't deliver O2 to cells and they will die.
172
How is Carbon Monoxide a problem with respiration?
CO combineds with HgB in same location as O2 but has a greater binding affinity than O2 so it will always win.
173
What Pco allows CO to compete w/ O2 in combining w/ HgB?
What Pco is lethal?
.44mmHg CO
Allows 1/2 HbB to bind w/ CO
Pco .6mmHg
174
Will a patient with CO poisoning look cyanotic?
No, don't show signs or symptoms of O2 loss.
175
What reaction can displace CO with O2 on Hgb?
Hyperbaric Rx
176
What are the three forms of CO2 transport?
HCO3 (bicarbonate), HbCO2, Dissolved
177
How many ml of CO2 per 100ml of blood is transported from tissues to lungs?
4ml CO2
178
What percentage of CO2 is transported as bicarbonate? HbCO2? Dissolved?
```
HCO3 = 85-90%
HbCO2 = 5%
Dissolved = 5-7%
```
179
What is the chemical reaction for bicarbonate formation?
CO2 + H2O --> H2CO3 --> H+ HCO3
180
Normall, how many ml of CO2 per 100ml of blood?
50 volumes percent = 50ml CO2 per 100ml Blood
| 4ml is exchanged during normal blood transport
181
How does CO2 affect ph?
CO2 picked up in the tissue capillaries can decrease arterial blood pH
7.41 -> 7.37
w/release of CO2 in lungs --> pH returns to normal
182
Which diffuses faster, CO2 or O2? Why?
CO2
- More soluable (20% more b/c of molecular attraction to water)
- Less pressure difference needed to cause CO2 diffusion than O2 diffusion
--remember at same partial pressure, CO2 diffuses almost 20x faster.
183
If there is a decrease in blood flow at tissue interstitial fluid, what is the result on PCO2 in fluid?
Increase in Blood Flow? Increase in Metabolism?
PCO2 in fluid
| > BF @ tissue ISF → metabolism → > ISF PCO2 @ all BF levels
184
What is Respiratory Quotient equation?
RQ = CO2 Produced / O2 Consumed
185
What is the Respiratory Quotient a ratio of? How does it differ? What does it approximate?
- Ratio of metabolic gas exchange.
- Differs depending on type of substrate metabolized: Carbs, Fats, Proteins
- Approximates nutrient mixture catabolized for energy during rest and exercise
186
What does Respiratory Exchange Ratio compare?
R > 1 means?
R
CO2 output to O2 intake
R > 1 means?
- Hyperventilation
- Exhaustive Exercise
- Lipogenesis
R
187
Eupnea:
Apneustic Breathing:
Apnea:
Hyperpnea:
Eupnea: normal respiratory rate and rhythm
Apneustic Breathing: prolonged inspirations
Apnea: cessation of breathing
Hyperpnea: increase in ventilation
188
What are the 3 primary groups of neurons in the brainstem respiratory center?
Dorsal Respiratory Group
Ventral Respiratory Group
Pnemotaxic Center (pontine respiratory group)
189
DRG
Location:
Main Function:
Sensory Info From:
DRG
Location: Medulla
Main Function: Main controller of inspiration: sets basic respiration rhythm
Sensory Info from: CN9+10 - peripheral chemoreceptors, baroreceptors, lung receptors.
190
How does signal from DRG work to regulate breathing? Where do they travel?
APs from DRG ramp up and signal inspiritory muscles, diaphragm, to contract.
travel along reticulospinal tracts in SC --> phrenic n. and intercostal n.
191
What is the point of ramping up of DRG signal? Why does the signal suddenly stop?
Ramping up precents jagged breathing.
Signal stop for 3s to stop stimulating diaphragm contraction for recoil and exhalation.
192
VRG
Location:
Main Function:
VRG
Location: Medulla
Main Function: OVERDRIVE, normally inactive during quiet breathing, however with ventilatory needs -->inhalation/exhalation: diaphragm + ABS
193
PRG
Location:
Main Function:
PRG
Location: Pons
Main Function: INHIBITORY, adjusts breathing rate.
Signals DRG, determines off point of inspiration ramp -> limits inspiration
194
Strong PRG Signal:
| Weak PRG Signal:
Strong Signal: short lung filling time
-Limit ramp time -> shorter insp and exp time -> increased breathing rate.
Weak Signal: longer lung filling time
195
In what two ways can control of inspiritory ramping occur in the DRG?
1. Rate of increase of ramp signal - can occur quickly when needed for rapid breathing.
2. End of ramping - provides limit to time of inspiration, usual method for controlling rate of respiration.
196
What is the function of Hering-breuer reflex?
Stretch receptors in walls of bronchi and bronchioles signal DRG when overstretch to turn ramp off.
Increases respiritory rate similar to pneumotaxic center.
197
Which gas molecules have a direct effect on respiration?
CO2 and H
198
What role to Central Chemoreceptors have (chemosensitive area in medulla)?
What does it signal to adjust?
acute effect of increase CO2 and H concentration.
-Strongly affected by changes in blood concentrations but primarily H+ because crosses BBB.
Stimulates other parts of respiratory center.
199
What is the Long-term control of excitation of CO2?
Effects of increased CO2 decrease over 1-2 days b/c of renal adjustment.
200
Describe short and long terms effects of an increase in blood CO2. What does this mean for a patient with COPD?
Strong acute effect on controlling respiratory drive, BUT weak chronic after 1-2 days because of adaptation.
COPD, not always breathing hard due to adjustment.
201
What role do Peripheral Chemoreceptors have? How do they compare to Central Chemoreceptors?
Not as powerful as direct effects on respiratory center, however 5x faster.
Might offer important role at onset of exercise.
202
Does O2 have a direct or indirect effect on (central) respiratory center?
indirect.
203
Why is O2 usually not the main driver of respiration?
O2-Hgb buffer system ensures enough O2 delivery through wide range of PO2.
204
What mechaism is there to assure O2 delivery when blood O2 falls too low?
Peripheral Chemoreceptors System (glossopharngeal carotid bodies and vagus aortic bodies) primarily respond to cchanges in blood O2 and transmit nervous signals to DRG.
Will have a rapid response if PO2 falls between 30-60mmg.
205
If CO2 and H+ are kept constant, and PO2 drops from 140 slowly to 60mmHg what will we see?
Not much until hits 60mmHg and ventilation will double.
206
What happens to your CO2 and O2 response as you adapt to high altitude?
- Respiratory center in brainstem loses ~4/5 of sensitivity to changes in PCO2 and H+ over 2-3 days.
- Excess ventilation reduces CO2 so system to increase respiration fails.
- Low O2 can drive system now.
207
What can the brain do at the onset of exercise to affect ventilation?
Brain - may initially stimulate respiratory center in brainstem when sending motor impulses to the working muscles = "anticipatory stimulation"
CO2 will then take over.
208
What are the 6 other factors that can influence ventilation?
1. Pain: hypothalamic control - stimulation of respiratory center
2. Pulmonary irritant receptors: Trachea, bronchi, bronchioles, lung receptors
3. Proprioceptors: motion of limbs
4. Brain edema
5. Anesthsia
6. ANP - Atrial Naturetic Peptide
209
What are the effects of Hyperventilation on CO2?
| Treatment?
Increase in rate and depth of breathing - exceeds need to remove CO2.
Low blood CO2 = hypocapnia -> cerebral vasoconstriction -> diziness
Treatment: bring CO2 back in brown bag.
210
What are the effects of CO2 on a patient with emphysema?
Retention of CO2 occurs and levels are chronically elevated so chemoreceptors adapt.
Decrease PO2 acts on peripheral chemoreceptors and provides main stimulus for respiration = hypoxic drive
If give pure O2, body doesn't recognize need to increase ventilation and stop breathing.
211
```
How is Obstructive Pulmonary Disease defined?
Total Lung Capacity?
Reserve Volume?
Forced Vital Capacity?
FEV1?
FEV1/FVC?
```
- Air gets trapped in lungs = impacted flow
- Obstruction of airflow --> air trapped in lungs.
```
TLC slightly increases
RV increases
FVC same or greater
FEV1 decreases
FEV1/FVC decreases
```
212
```
How is Restrictive pulmonary disease defined?
Total Lung Capacity?
Forced Vital Capacity?
FEV1?
FEV1/FVC?
```
-Volume impacted, restricted lung expansion --> decrease lung volumes.
TLC decreases
FVC decreased
FEV1 decreases slightly
FEV1/FVC increases
213
What are the nonseptic forms of COPD?
Chronic bronchitis, emphysema, asthma, bronchiectasis
214
What are the septic forms of COPD?
Cystic Fibrosis, bronchiectasis.
215
What restrictive lung diseases?
Interstitial Lung Disease, Idiopathic Pulmonary Fibrosis (IPF)
216
What are characteristics of Emphysema?
- chronic =copd
- Less surface area in alveoli
- Obstructive Disease - able to get air in but hard time getting it out
- Often from smoking
- Abnormal/permanent enlargement of air spaces distal to terminal bronchioles + destruction of alveolar wall
- Airflow limitation b/c loss of elastic recoil.
217
COPD main characteristics.
- Not fully reversible and progressive.
| - Associated w/ abnormal inflammatory response of lungs to inhaled noxious particles gasses.
