Norm fxn- Physiology Flashcards
1
Q
Which is the primary muscle for inspiration?
A
Diaphragm
2
Q
What is the biggest accessory muscle to help the diaphragm in inspiration?
A
Ext intercostals
3
Q
Give me 3 other accessory muscles to aid in inspiration.
A
SCM
Anterior Serrati
Scalenes
4
Q
True or False: expiration is usually passive from the normal recoil of the lungs, chest wall, and abd structures.
A
True!!!!!!!!!!!!!!!!!!!
5
Q
What are the main expiratory accessory muscles to aid in expiration if passive recoil isnt enough? (2)
A
Abd muscles and internal intercostals
6
Q
What causes the normal negative pressure within the pleural space?
A
excess pleural fluid is suctioned into the lymphatic channels continuously.
7
Q
What is the normal transmural pleural pressure at rest?
A
-5cm of H2O
8
Q
During inspiration, what does the negative transmural pressure jump to?
A
-7.5cm of H2O
9
Q
The increase of negative pressure causes how much volume to be sucked into the lung during normal respiration?
A
0.5L of air
10
Q
When no air is flowing in/out of the lungs, what is the pressure of the alveoli equal to?
A
Atmospheric pressure (0cm of H2O)
11
Q
During inspiration, what does the P(alv) drop to?
A
-1cm of H2O
12
Q
The drop in P(alv) during inspiration causes what to happen?
A
Air flows into the lungs
13
Q
This is the extent to which the lungs will expand for each unit increase in transpulmonary pressure.
A
Compliance
14
Q
Compliance of the lungs is determined by what 2 properties of eslastance?
A
- elastic forces of the lung tissue itself
2. eslastic forced caused by the surface tension of the fluid inside the walls of the alveoli
15
Q
How much of the total elastic forces are contibuted by only the tissues itself?
A
1/3
16
Q
So the other 2/3 of elastic forces are due to what other elastic factor?
A
surface tension
17
Q
In emphysema, there is a destruction of the elastic tissue, causing a change in elasticity and compliance how?
A
↓ elasticity
↑ compliance
18
Q
Is there an ↑ or ↓ in compliance in fibrotic lung disease?
A
↓
19
Q
Upon full inspiration (to VC), will mostly elastance or compliance effects from the lungs be in place?
A
Elastance
20
Q
What happens to the transpulmonary pressure when you have a pneumothorax?
A
it equals atmospheric, so no neg pressure will be made, and thus no air will flow in.
21
Q
This is the volume of inspired or expired air ina normal breath (~0.5L).
A
Tidal volume (TV)
22
Q
This is the extra volume that can be inspired over the TV (~3L).
A
Inspiratory reserve volume (IRV)
23
Q
This is the max extra volume that can be expired after the end of a normal TV (~1L).
A
ERV
24
Q
This is the volume of air remaining in the lungs after the most forceful expiration (~1.2L).
A
Residual volume (RV)
25
This is the volume of IRV + TV + ERV.
Vital capacity (VC)
| the "blowing out the birthday candles" volume
26
This is the volume of ERV + RV.
Functional residual capacity (FRC)
27
This is the volume of VC + RV
Total lung capacity (TLC)
28
What substance is the main contributor to surface tension?
Water
29
And again, does surface tension ↑ compliance or elastance?
Elastance (2/3 of all elastic forces for the lungs)
30
What is the eqn to see the collapsing prssure of the alveoli?
(Pressure to keep alveoli open) = (2 x surface tension)/(radius of alveolus)
Lapace law
31
According to Lapace law, air will flow into a larger or smaller alveoli?
Larger, because an ↑ in radius ↓ the pressure required to keep the alveolus open
(P = 2T/r)
32
This is the collapse or closure of the lung from reduced or absent gas exchange.
Atelectasis
33
What are the 4 main components of surfactant?
phospholipids, DPPC, surface apoproteins, and Ca++ ions
34
Which cells make surfactant?
Type II alveolar cells
35
What is the role of surfactant for the lungs?
Reduce surface tension --> reduce pressure to keep the alveolus open
(P = 2T/r)
36
True or false: the alveoli at the apex of the lung are larger than the alveoli at the base of the lung due to gravity.
True
37
Since the alveoli at the apex of the lung are larger, is their compliance lower or higher?
Lower
38
What is the eqn for minute respiratory volume?
MRV = TV x (respiratory rate)
39
This is the total exchange of air in the lungs.
Pulmonary ventilation
40
This is the amount of new air that reaches the alveoli in 1 min.
Alveolar ventilation
41
This si the volume of air in the conducting pathways that does not partiipate in gas exchange.
Anatomic dead space
42
This is not really a volume, but when alvoli are nonfxnl or partially fxnl.
Alveolar dead space
43
this is the total dead space and made from anatomic + alveolar dead space.
Physiological dead space (VD)
44
What is the alveolar ventilation eqn?
Va = rate x (VT - VD)
always make sure to substract dead space when calculating alv vent. they will have answers on the exam where the #'s match if you didn't subtract it out.
45
The SANS causes what to the bronchioles, dilation or constriction?
Dilation
46
Histamine is a big factor in anaphylactic conditions, which causes what to the bronchioles, dilaiton or constriction?
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47
This is when VENTILATION is inadequate to perform needed gas exchange.
Hypoventilation
48
This is when u breathe too much because your heart is racing from seeing your boyfriend of 8 months return from a long business trip in taiwan and you're ignoring the fact that he night have gotten the clap form that questionable toilet seat.
Hyperventilation
49
This is when there's too much CO2 in the blood
Hypercapnea
50
This is normal breathing
Eupnea
51
This is shallow breathing or an abnormally low respiratory rate.
Hypopnea
52
This is an increased depth of breathing in order to meet metabolic needs.
Hyperpnea
53
Are brochial aa. that supply the lung system with delicious nutricious arterial blood high pressure or low pressure?
High
54
Is blood from the pulmonary a. high pressure or low?
Low
55
What is the BP of the RV?
25/8
56
What is the MAP of the pulmonary a.?
15mmHg
57
What is the MAP of the pulmonary capillaries?
7mmHg
58
What is the MAP of the LA?
2mmHg
59
When PO2 drops below 73mmHg, do small arteries constrict or dilate?
Constrict
60
Why do small arteries constrict under hypoxia?
Diverts blood to the areas where it's most effective
61
Why is there no blood flow in Zone 1?
P(alv) is greater than arterial pressure
62
What changes can cause intermittent blood flow in Zone 2?
When systolic arterial pressure overcomes P(alv)
63
True or False: arterial flow is continuous in a Zone 3 of the lung.
True
64
The apices of the lungs typically have which zone (1, 2, or 3)?
zone 2
65
The base of the lungs typically have which zone (1, 2, or 3)?
zone 3
66
So when do you get a zone 1?
severe blood loss or breathing against a + air pressure
67
During exercise, does increasing the # of open capillaries, distending the capillaries, and increasing pulmonary arterial pressure increase or decrease blood flow?
Increase about 4-5x normal
68
At what pressure do u see pulm edema from LHF?
>30mmHg
69
During lung inflation, what happens meechanically to alveolar vessels to increase pulm resistance?
Mechanically compressed
70
What is the colloid pressure of the pulmonary interstitial fluid?
14mmHg
71
What is the equation to relate partial pressure with solubility?
P = (conc of gas)/(solubility coefficient)
72
How do you calculate PO2 in atomospheric air?
PO2 = (760mmHg - 47mmHg)*0.21 = 150mmHg
the 47 comes from water
73
What are the 4 factors that affect the rate of gas diffusion across the respiratory membrane?
1. thickness
2. surface area
3. diffusion coefficient
4. partial pressure difference of the gas
74
Ventilation and perfusion are highest where, at the apices or bases of the lung?
Base
75
Where is the V/Q ratio the highest, at the apices or bases of the lung?
Apices
| lots of ventilation but poor perfusion
76
Where is PCO2 hihger, at the apices or bases of the lung?
Base
77
Where is PO2 higher, at the apices or bases of the lung?
Apices
| cuz there is more gas exchange
78
What is the V/Q at the portion of the lung if there is a blockage?
0
79
Will a PE ↑ or ↓ V/Q?
↑ a lot
80
In high altitude, what will happen with the PaO2 and A-a gradient?
PaO2 ↓
| A-a normal
81
In hypoventilation, what will happen with the PaO2 and A-a gradient?
PaO2 ↓
| A-a normal
82
In fibrosis (diffusion defect), what will happen with the PaO2 and A-a gradient?
PaO2 ↓
| A-a ↑
83
In a V/Q defect, what will happen with the PaO2 and A-a gradient?
PaO2 ↓
| A-a ↑
84
In a R-L shunt, what will happen with the PaO2 and A-a gradient?
PaO2 ↓
| A-a ↑
85
How do you calculate PAO2?
PAO2 = (PIO2 - PACO2)/R
where R= respiratory exchange ratio or respiratory quotient
86
What is the PO2 and PCO2 of inspired air?
PO2- 160mmHg
| PCO2- 0.3
87
What is the PO2 and PCO2 in the alveoli?
PO2- 104
| PCO2- 40
88
What is the PO2 and PCO2 of the pulmonary a.?
PO2- 104
| PCO2- 40
89
What is the PO2 and PCO2 of arteries?
PO2- 95
| PCO2- 40
90
What is the PO2 and PCO2 of veins?
PO2- 40
| PCO2- 46
91
The amount of time blood is in the pulmonary artery decreases when there is an increase in what factor during exercise?
Cardiac output
92
The ↓ in the time the blood is in the capillary does what to the amount of O2 that diffuses?
↓
93
However, there is a safety mechanism to counter the ↓ of time of blood in the capillary during exercise, because normal blood gets fully oxygenated by passing through what length of the capillary?
Fully oxygenated during the first 1/3 of the capillary
94
So during exercise, the ↑ CO doesnt matter cuz blood can still get oxygen during what remaining span of the capillary?
The remaining 2/3, so we're sitll fully oxygenated.
95
Does ↑ tissue blood flow ↑ or ↓ PO2?
↑ PO2
96
Does ↑ tissue metabolism ↑ or ↓ PO2?
↓ PO2
97
True or False: the rate of diffusion of CO2 and O2 are essenitally the same across capillaries.
FALSE. CO2 can diffuse about 20x as rapidly as O2
98
Does ↑ blood flow ↑ or ↓ PCO2?
↓ PCO2
| takes away more CO2 faster
99
Does ↑ tissue metabolism ↑ or ↓ PCO2?
↑ PCO2
| making more CO2 ↑ PCO2 omgomgomgg
100
What % of O2 is bound to Hb?
98.5% according to Little
| book says 97%
101
What is the VOLUME of O2 in the blood (per 100mL) when Hb is fully saturated?
20mL
102
What is the volume of O2 that is transported from the lungs to the tissues if we subtract the amt in the arteries from the amt in veins?
~5mL
103
This is the principle when increases in blood CO2 and H+ levels enhance the release of O2 from the blood in the tissues and enhances oxygenation of the blood in the lungs.
Bohr effect
104
An increase in what 4 things shift the O2-Hb dissociation curve to the R?
H+
DPG
CO2
Temp
105
What PCO is needed to be lethal from irreversible binding to Hb?
0.6mmHg
106
What % of CO2 is dissolved?
7%
107
What is the volume of dissolved CO2 transported around the body to the lungs? (use the difference between arterial and venous)
0.3mL
108
What % of CO2 gets converted to HCO3-?
70%
109
What enzyme converts CO2 and H2O into H2CO3?
Carbonic anhydrase
110
Once H2CO3 splits into H+ and HCO3 inside the RBC, what binds the H+?
Hb to form HHb
111
What exchanges for HCO3- on the membrane to put HCO3 into the plasma?
Cl-
112
So is venous blood [Cl-] higher or lower than arterial [Cl-]?
Lower
113
What % of CO2 directly binds to Hb to form carabinohemoglobin (CO2Hb)?
23%
114
This is the principle when the binding of O2 displaces CO2 from the blood.
Haldane effect
115
Co2 is displaced from the Hb on the fact that the O2-Hb complex forms what, a stronger acid or stronger base?
Acid
116
What is the eqn for the respiratory exhcange ratio?
R = (rate of CO2 output)/(rate of O2 uptake)
117
What is the R when a person is eating exclusively carbs?
R = 1.00
118
What is the R when a person is eating exclusively fats?
R = 0.7
119
What is the R when a person is eating a balanced diet?
R = 0.825
120
What is the main function of the dorsal respiratory group of the medulla?
Causes inspiration
121
What is the main function of the ventral respiratory group of the medulla?
expiration
122
What is the main function of the pneuotaxic center of the superior pons?
Controls rate and depth of breathing
123
Where are the neurons in the medulla for the dorsal respiratory group?
Nucleus of the Tractus Solitarius (NTS)
124
Which 2 nerves give sensory innervation the NTS?
IX and X
125
The dorsal respiratory group emits what to contril the basic rhythm of breathing?
repetitive bursts of inspiratory neuronal action potentials
126
this is the form of information from the dorsal respiratory group to the diaphragm that begins weakly, increases steadily and then ceases.
Ramp signal
127
What 2 ways does the pneumotaxic center from the upper pons control the ramp signal to regulate breathing?
1. Limits the duration (early ceasing)
| 2. Increasing the rate of breathing
128
This is the center in the lower pons where there are deep and prolonged inspiratory gasps.
Apneustic center
129
True or False: during normal, quiet breathing, the ventral respiratory group neurons are inactive.
True!
130
So activation of the ventral respiratory gorup dring increased ventilation causes what?
Heavy expiration by activating abd muscles
131
True or False: H+ ions directly sitmulate the central chemoreceptors by crossing the BBB.
False. They can't cross the BBB. They need to be in the form of CO2 to cross the BBB
132
Which changes mainly stimulate the peripheral chemoreceptors, changes in O2 or CO2?
O2
133
Where are the peripheral chemoreceptors in the body?
carotid and aortic bodies
134
Which nerves from the carotid bodies take the information to IX?
Herings nerves
135
IX (from the carotid bodies) and X (from the aortic arch) take information to where in the brain?
Dorsal Respiratory Group
136
At what PO2 are the peripheral chemoreceptors stimulated?
<60mmHg
137
Why is <60mmHg significant to stimulate the peripheral cehmoreceptors?
Cuz at a PO2 of 60mmHg, 90% of Hb is saturated (from looking at the dissociation curve)
138
True or False: although peripheral chemoreceptors don't respond well to PCO2 or pH, they respond more rapidly than the central chemoreceptors.
True
139
Which has a stronger regulatory effect of ventilation, PCO2 or pH?
PCO2
140
What are the changes in the central chemoreceptors to acclimatize for high altitudes?
It loses its sensitivity to changes in PCO2 and H+ ions
141
What causes an immediate increase in ventilation (anatomically) during exercise?
the brain simulation the exercising muscles send simultaneous signals to the respiratory center to ↑ respiration
142
These are receptors on the musucular portions of the walls of the bronchi and bronchioles and signals the DRG to prevent overstretching.
Stretch receptors
143
THis is the reflex where stretch receptor activation stops the inspiration.
Hering-Bruer Inflation Reflex
144
Which receptors are initiated to causes coughing and sneezing?
Irritant receptors
145
Irritant receptors may also be responsible for bronchial constriction or dilation?
Constriction
146
These are the receptors in the alveolar walls next to pulmonary capillaries and are stimualted when pulmonary capillaries ahve become engorges with blood or fluid.
J (juxtacapillary) receptors
147
J receptor activation causes what Sx?
Dyspnea (difficult, rapid, shallow breathing).
148
What is the FEV1 for a normal lung?
80%
149
Which disease causes a decreased FEV1, obstructive or restrictive pulmonary disease?
Obstructive
150
Is FEV1 increased or decreased or normal in restrictive lung diseases?
Increased
151
What happens to TLC, RV, and max expiratory flow in obstructive lung disease?
TLC ↑
RV ↑
Max expiratory flow ↓
152
What happens to TLC, RV, and max expiratory flow in restrictive lung disease?
TLC ↓
RV ↓
Max expiratory flow ↓
153
What type of therapy is 100% effective if there is atmospheric hypoxia?
O2
154
Will O2 therapy help with hypoventilation hypoxia?
yes a good amt.
155
However, in hypoventilation hypoxia, O2 therapy doesnt get rid of what?
CO2
156
Is O2 therapy veneficial in anemia, abnormal Hb, circulatory deficicency, or physiological shunts?
A tiny bit
157
Is O2 therapy beneficial in hypoxia from inadequate tissue use of O2?
NO
