Exam I: Pulmonary Flashcards
(422 cards)
1
Q
what are the key parts of respiration
A
ventilation-moving air into lungs
diffusion- exchange with blood at alveoli
transport- moving gases to tissues
transfusion/perfusion- gas exchange with tissues
2
Q
what is the mucucilliary system (clearance)
A
cells with hairs lines upper and lower respiratory tract,
secrete a sticky mucus layer
spin the incoming air and trap viruses/bacteria in sticky layer
wash layer back to larynx to be killed by HCl in stomach
3
Q
what saves us from constant PNA
A
coughing/sneezing
mucocilliary system
macrophages in alveolus
4
Q
what happens in the conducting zone of the airway
A
transports and distributes air
warms and humidifies air
traps and clears harmful particles in mucus
5
Q
what resp structures make up the conducting zone
A
trachea
bronchi
bronchioles
terminal bronchioles
6
Q
what happens in the respiratory zone of the airway
A
exchange gas across alveolar capillary membrane
7
Q
what structures make up the respiratory zone
A
respiratory bronchioles,
alveolar ducts,
alveolar sacs
8
Q
what cells makes up the alveoli tissue
A
simple squamous epithelium
9
Q
what tissues are present between gas in alveoli and gas in blood
A
epithelial cells of alveolus
endothelial cells of capillary
thin layer of fluid between
10
Q
where is surfactant produced
A
type II alveolar cells
11
Q
what structures are within the alveoli
A
type 2 alveolar cells- produce surfactant
basement membrane- structure of alveoli(type I alveolar cells)
elastin- recoil of alveoli
alveolar epithelium- where it makes contact with capillaries
12
Q
what is role of surfactant
A
reduces surface tension
13
Q
every alveolus has a __________ to prevent infection
A
macrophage
14
Q
how many true ribs are there
A
7 pairs
15
Q
how many false ribs are there
A
5 pairs (2 are floating)
16
Q
how many floating ribs are there
A
2 pairs
17
Q
inner intercostal and external intercostal muscles run in ___________ directions
A
opposite
18
Q
what are the steps of inspiration
A
-diaphragm contracts
-sternocleidomastoid pulls sternum and 1st rib
-ribs elevated by scalenes, pec minor, and external intercostals
-rib cage turns out like bucket handle
causes an increase in volume and negative pressure
19
Q
what are the steps of expiration
A
passive exp
elasticity of alveoulus
active exp
internal intercostals and abd muscle
causes a decrease in volume and positive pressure
20
Q
Where is the visceral pleura?
A
on external lung surface
21
Q
where is the parietal pleura
A
lines the thoracic cavity
22
Q
what is between the visceral and parietal pleura
A
pleural cavity with thin layer of fluid
23
Q
what is purpose of constant negative pressure in pleural cavity
A
suck lungs to rib cage
24
Q
what law tells us about the relationship between pressure and volume
A
boyles law
inverse relationship
25
what law tells us about the relationship between volume and temp
charles law
direct relationship
26
what does pressure have to be for inspiration
at least 758 (ATM is 760)
27
what does pressure have to be for expiration
at least 761
28
what is the law of partial pressures
Daltons law
29
what is PO2 of venous blood
40mmhg
30
What is the PO2 of alveolar air?
105 mmhg
31
What is the PCO2 in the alveoli?
40 mmhg
32
what is PCO2 in the venous blood
46 mmhg
33
what is PO2 of atomoshpheric air
159
34
what causes diffusion process to occur between alveoli and capillaries
partial pressure difference
35
What is the PO2 of arterial blood?
100 mmhg
36
what is PCO2 of arterial blood
40
37
what is Paw
partial airway pressure
38
what is P A
alveolar pressure
39
what is Ppl
pleural pressure (pleural space)
40
what is Pta
Transairway pressure (tracheal wall)
41
what is PL
transpulmonary pressure
(pressure between alveoli sac and pleural cavity) (pressure within lung tissue)
42
what is Pl at rest
-5 cm H2O
43
Pta = ________ - __________
Paw (airway) - Ppl (pleural pressure)
44
Pl = _________ - ___________
P A (alveolar) - Ppl (pleural)
this is a negative pressure compared to ATM
45
what creates Ppl
elasticity of lungs
46
why do your lungs collapse in pneumothorax
no longer - pressure, becomes + so lungs collapse
47
Ppl ________ during inspiration and _________ during expiration
decreases
increases
48
P A _________ and returns to zero during inspiration and __________ then returns to zero during expiration
decreases
increases
49
when do we read peak tidal volume
end of inspiration
50
what are the 4 volumes we measure in lungs
inspiratory reserve volume
tidal volume
expiratory reserve volume
residual volume
51
what is total lung capacity formula?
inspiratory reserve volume
tidal volume
expiratory reserve volume
residual volume
or
vital capacity + residual volume
52
What is vital capacity formula?
inspiratory reserve volume + tidal volume + expiratory reserve volume
53
What is inspiratory capacity formula?
tidal volume + inspiratory reserve volume
54
what is functional residual capacity formula?
expiratory reserve volume + residual volume
55
what is normal tidal volume
500 ml
56
what is normal IRV (inspiratory reserve volume)
3100 ml
57
what is normal ERV (expiratory reserve volume)
1100 ml
58
what is normal RV (residual volume)
1200 ml
59
what is the definition of inspiratory capacity
The maximum amount of air that can be inspired after the expiration of a normal breath at rest
60
what is normal inspiratory capacity (IC)
3500 (TV + IRV)
61
What is FRC (functional residual capacity)?
Amount of air that Remains in lungs at the end of normal expiration
62
what is normal FRC
2400 (ERV + RV)
63
what is VC (vital capacity)
Maximum amount of air expelled from lungs after first filling the lungs to a max then expiring to a max
everything - residual volume
64
what is normal VC
4800 TV + IRV + ERV
65
What is TLC (total lung capacity)?
Maximum volume of air the lungs can hold
66
what is normal TLC
6000 (IC + FRC) (or all volumes)
67
what is FEV1
maximum forced expiratory volume in 1 second
68
what is FVC%
percentage of FVC forcibly exhaled in one second
69
what condition do we use FEV1 and FVC% tests for
COPD
bronchitis
emphysema
70
what factors influence VC
size (height)
environment
71
what factors change lung functions throughout life
lung damaging activities (smoking)
exercise
age
72
what is Minute ventilation (MV)
TV x RR
volume of air moved in a minute
73
what is anatomic dead space in lungs
volume of conducting zone that takes up space but does not exchange gas
74
where does stale air come from
anatomic dead space, air that is not exchanged
75
what causes alveolar dead space
inadequate perfusion of ventilated alveoli
76
what is antomical + alveolar dead space
physiologic dead space volume
77
what is normal amount of lung being used
1/3
78
T/F with alveolar dead space shallow/fast breathing is more effective than deep slow breathing
false, deep slow breathing allows for movement in dead spaces
79
how does hyperventilation affect PCO2
Decreased arterial PCO2 (increases pH)
80
how does hypoventilation affect PCO2
increased arterial PCO2, decreases pH
81
What is compliance of the lungs?
how much effort is required to stretch the lungs and chest wall
82
lung A has set pressure with low volume
lung B has same pressure with higher volume
which lung is more compliant
B
83
what condition has increased compliance but decreased recoil
emphysema
84
how does surfactant affect compliance
increases compliance
85
how do we measure lung compliance
spirometer
86
how does COPD affect lung compliance
increased compliance with decreased elasticity
87
How does ARDS affect lung compliance?
decreased compliance (less surfactant)
88
how does scarring affect lung compliance
decreases
89
how does pneumonia affect lung compliance
decreases
90
how do restrictive diseases affect lung compliance (asthma)
decreases
91
what is recoil direction of rib cage
inward
92
what is recoil direction of lungs
outward
93
where do opposing recoil of lungs and rib cage meet
FRC functional residual capacity
94
how does standing affect lung compliance
-top of lung stretched by gravity
-lower lung more compliant
-upper lung less compliant
95
what is purpose of surfactant
* Reduces surface tension
* Stops alveoli collapsing and sticking together
96
without surfactant compliance would ___________
decreases
97
what determines resistance in airway
radius
98
what leads to increased resistance in lungs
bronchoconstriction:
parasympathetic stimulation
environmental insults (smoke, cold)
99
what leads to decreased resistance in lungs
sympathetic stimulation
high CO2
100
where is turbulent airflow found
highest in smaller bronchi
increases in velocity
101
how does turbulence affect resistance
increases
102
how does lung volume affect resistance
increased lung volume decreased resistance
103
how does forced expiration affect airway pressures/resistance
compresses airway with positive pressure, increasing resistance
104
when does the lung have the most resistance
high and low volumes
105
what is the equal pressure point
point in the lung where pleural pressure is same as terminal bronchiole
during peak expiration, pressure is same inside and outside lung
lower pressure of conducting airway is protected by cartilage
106
what part of airway are we in after reaching EPP
conducting airway, protected by cartilage
107
how does emphysema affect EPP
EPP moves to smaller branches without cartilage, so air cannot be moved out
108
how does asthma (restrictive lung disorder) affect lung "work"
increases inspiratory work
109
how does emphysema (obstructive lung disease) affect lung "work"
increased expiratory work
110
why do pulmonary vessels need to be compliant
to accommodate stroke volume variations from R vent
111
what percent of CO goes through pulmonary circulation
100%
112
what is the purpose of pulmonary circulation
bring blood into contact with alveoli for gas exchange
113
what is inspired air
PO2
PCO2
159 mmhg (160?)
0.3 mmhg
114
what is alveolar air
PO2
PCO2
104 mmhg (102?)
40 mmhg
115
what is arterial blood
PO2
PCO2
95-105 (100) mmhg
40mmhg
116
what is tissue fluid
PO2
PCO2
40 mmhg
46 mmhg
117
what is venous blood
PO2
PCO2
40 mmhg
46 mmhg
118
what causes diffusion in lungs
concentration gradient/ partial pressure
119
what does the lung filtrate
emboli
thrombi
-small blockages in lungs are better than in heart, brain, kidneys
120
what is the fucntion of the lung for metabolism
formation of angiotensin 2 by ACE
inactivation of bradykinin, prostaglandins
121
what are the lungs a reservoir for
hemorrhagic shock
122
what are the three secondary functions of the lungs
filtration of embli/thrombi
metabolism
blood reservoir
123
what kind of blood is in pulmonary arteries
deoxygenated
124
what kind of blood is in pulmonary veins
oxygenated
125
where does bronchiole circulation come from
R lung -third post intercostal
L lung- aorta
126
what is function of pulmonary circulation
pick up O2 in lungs
127
what is function of bronchiole circulation
oxygenate lung tissue
128
how is pressure in pulmonary circulation when compared to systemic
low resistance, low pressure
129
pulmonary vessels have _______ smooth muscle
less
130
what is pressure of systolic and diastolic in pulmonary circulation
15/5
131
how does an increase in CO affect pulmonary resistance
decreases
132
what is lung recruitment
opening of more capillary beds to contact alveolar sacs
capillaries also dilate
133
what are the three ways lungs increase capacity
recruitment
distension
dilation
134
what is the purpose of recruitment
increased flow at low velocity allows for greater gas exchange
increased areas of capillaries available for gas exchange
lowers pressure and prevents pulmonary edema
135
how does a high lung volume (increased alveolar size) affect resistance
**INSPIRATION**
pleural pressures more negative, extra-alveolar vessels expand
expansion of alveolus compresses alveolar vessels, increasing resistance
136
how does a low lung volume affect resistance
**exhalation**
more positive pleural pressures compress extra-alveolar vessels
increases resistance
137
what is the time of lowest resistance in lungs
-FRC (functional residual capacity)
volume at rest after passive expiration
-least compression of blood vesses
138
how does hypoxia (low O2 tension) in alveoli affect pulmonary vessel resistance
causes pulmonary vasoconstriction
139
why does hypoxia of alveoli cause pulmonary vasoconstriction
maintain ventilation/perfusion balance
shunt blood to areas of higher oxygenation
140
how does generalized hypoxemia affect pulmonary vasculature
pulm vasoconstriction
141
what has a lower hydrostatic pressure, capillaries or alveoli
capillary
142
what creates pressures within the alveoli
air pressure (pushing out)
surface tension (pullin in)
143
what creates pressure within the pulmonary capillary
hydrostatic pressure (pushing out)
colloidal osmotic pressure (pulling in)
144
what fluids are around alveoli/capillary
interstitial fluid
lymph drainage
145
what is the normal net filtration pressure of capillary to interstitial space
+1 mmhg
146
a negative hydrostatic pressure of the interstitial fluid leads to a ____________ affect from the capillary
suction
147
what direction does fluid go between capillary, interstitial space, and alveoli
in normal conditions goes from capillary to interstitial fluid
148
where does excess fluid from interstitial space go
lymphatic system (has a pressure of -5 mmHg)
149
where does excess fluid from alveoli go
interstitial fluid
150
What is physiology of pulmonary edema?
pressure in pulmonary capillaries increases from L sided HF
pressure in interstitial space is greater than +5 mmHg,
fluid cant drain completely into lymphatics
fluid goes into alveoli
pulmonary edema
151
what condition causes pulmonary edema
L sided HF
damage to pulmonary membrane
152
what safety factors protect us from death r/t pulmonary edema
negative interstitial pressure
lymphatic pumping
decreased interstitial osmotic pressure
153
when standing up, the lung has more - pressure, the top of the lung is stretched, and compliance of lung is ____________ so more air goes to __________ part of lung because it is _________ compliant
decreased
lower
more
154
when standing which part of the lung has more perfusion and ventilation
base of the lung (gravity and compliance effects)
155
what is Zone 1 of lung
not normal
PA (alveoli) is greater than Pa (arteries)
alveoli compresses arteries
156
what is zone 2 of lung
Pa (arteries) > PA (alveoli) > Pv (venous)
flow limited by alveolar pressure, dialating venules will not increase flow
157
what is zone 3 of the lung
Pa >Pv>PA
blood flow is not determined by alveolar pressure
158
how does gravity affect V/Q
V/Q mismatch
perfusion higher in base of lung
V/Q low at base (excess blood in base)
V/Q high at apex (excess air at apex)
159
what is normal V/Q
1/1
160
how does airway obstruction affect V/Q ratio
low V/Q ratio
161
low V/Q is a ________ issue
ventilation
162
in a low V/Q ratio
PAO2 ______ normal
PACO2 ______ normal
less than
greater
163
in a high V/Q ratio
PAO2 ______ normal
PACO2 ______ normal
greater
less than
164
an arterial obstruction causes a _________ V/Q ratio which causes ___________
high
dead space
165
what diseases cause low V/Q ratio
COPD
bronchitis
asthma
emphesymea
166
what causes a high V/Q ratio
pulm embolism
167
Does FiO2 change with altitude?
no, PaO2 changes
168
PAO2 is
alveolar O2
169
paO2 is
arterial O2
170
what causes drop of atmospheric O2 to alveolar O2
converted to water with CO2 to humidify air (turbinates)
171
what are factors that affect diffusion
Ficks
thickness of membrane
surface area of membrane
diffusion coefficient
partial pressure difference
172
how does PNA affect diffusion
thicker walls 2/2 edema = decreased diffusion
173
CO2 diffuses _______ than O2
faster
174
How much O2 is dissolved in plasma?
2%
175
How much CO2 is dissolved in plasma?
10%
176
what limits the diffusion of O2 and CO2 between capillaries and alveoli?
perfusion, not diffusion rate
177
what medication can increase diffusion between capillaries and alveoli
N2O
178
what percent of lungs do we usually use
30%
179
what increases the diffusion capacity of respiratory membrane
exercise
180
what happens inside lung to increase lung capacity to exchange O2 CO2
opening of dormant capillaries and increasing of diffusion capacities
(recruitment)
181
amount of O2 and CO2 in tissues is equal to the amount of O2 and CO2 in ________________
venous blood
182
how much O2 is carried on Hgb
98% (2% in plasma)
183
what is the affinity of RBC for carbon monoxide
250x O2 affinity
184
how does an increased metabolic rate affect PO2
decreases PO2
185
how does a decreased metabolic rate affect PO2
increases PO2
186
how does an increased metabolic rate affect CO2
increased
187
how does a decreased metabolic rate affect CO2
decreased
188
what factors affect Hgb affinity for O2
acidosis (H or CO2) = decreased affinity
pCO2 increased CO2 = decreased affinity
temp, increased temp = decreased affinity
DPG, increased DPG = decreased affinity
189
what is DPG
2,3-diphosphoglycerate
released by hypoxic cells
190
what does hgb decreased affinity for O2 mean
Hgb has a weaker hold, tissues receive O2 more easily, happens in response to increase metabolism or acidotic/hypoxic states
191
what does SaO2 tell us
% of binding sites occupied by O2
192
if a tissues has an unusually low PO2 Hgb gives up O2 __________ easily
more (decreased affinity for O2)
193
how does anemia affect SaO2
SaO2 can read 100% but still hypoxia
194
how does carbon monoxide affect SaO2
SaO2 can read 100% even in hypoxia
195
what is it called when oxygen combines with Hbg
oxyhemoglobin
196
what is a right shift in the oxyhemoglobin dissociation curve
decreased affinity for O2
197
what is a left shift in the oxyhemoglobin dissociation curve
increased affinity for O2
198
what processes cause a left shift in the oxyhemoglobin curve
alkalosis
decreased PCO2
decreased temp
low DPG
carboxyhemoglobin
Methemoglobin
abnormal hemoglobin
199
what causes a right shift in oxyhemoglobin curve
acidosis
high PCO2
increased temp
high DPG
abnormal hemoglobin
200
What is the Bohr effect?
shift in the oxyhemoglobin dissociation curve caused by changes in CO2 and H+ concentration in blood
201
How is CO2 transported in the blood?
70% Bicarbonate
20% on Hgb
10% Plasma
202
what catalyzes the process of CO2 and H2O forming H2CO3 (carbonic acid)
carbonic anhydrase
203
What is the chloride shift?
HCO3- ions move out of red blood cells into the plasma down a concentration gradient.
To maintain the electrical balance, Cl- ions take their place.
AKA hamburger shift
204
when Hgb is deoxygenated CO2 can bind to it, this creates
carbaminohemoglobin
205
What is the Haldane effect?
increased O2 = decreased Hgb affinity for CO2 (arterial blood)
decreased O2 = increased Hgb affinity for CO2 (venous blood)
206
blood can carry _______ CO2 than O2
more
207
when oxygen is attached to Hgb what is given off?
what does this then attach to?
what does this become
what breaks it down
what is then diffused out of RBC
H+
HCO3 from Cl- exchange
carbonic acid
carbonic anhydrase breaks it into CO2 and H20
CO2 diffuses out
208
What is pulmonary circulation?
circulation of deoxygenated blood between heart and lungs
209
what is bronchiole circulation
oxygenated blood to provide lung tissues
L lung from aorta
R lung from 3rd posterior intercostal arteries
210
where does deoxygenated blood from bronchiole circulation empty
pulmonary vein, so LA doesnt receive 100% saturated blood
211
a decreased V/Q ratio is a __________ issue
ventilation
212
an increased V/Q ratio is a _________ issue
perfusion
213
what are causes of VQ mismatch
PE (decreased perfusion)
COPD (decreased ventilation)
diffusion block (fluid in lungs)
asthma (decreased ventilation)
214
what has a greater impact on O2: ventilation or perfusion
ventilation
215
what two ways is O2 transported
2% in plasma
98% in RBC (hgb)
216
what are the 4 ways CO2 is transported
10% plasma
20% plasma bicarb
50% RBC bicarb
20% carbaminohemoglobin
217
why is plasma conversion of CO2 to bicarb slow
no carbonic anhydrase
218
why is plasma conversion of CO2 to bicarb fast
has carbonic anhydrase
219
what happens to bicarb in RBC when it reaches the lungs
breathed off as CO2
220
Where are peripheral chemoreceptors located?
carotid and aortic bodies
221
Where are central chemoreceptors located?
medulla oblongata
222
what are mechanoreceptors in the lungs sensitive to
stretch
J receptors
irritant (cough)
223
where is an area of high concentration of irritant mechanoreceptors
carina
224
what muscle are involved in inspiration
sternocleidomastoid- raises sternum
external intercostals- flips ribs out
diaphragm- pulls down
225
what is end result of inspiratory muscle movement
increased (-) pressure
-5 (baseline) to -10 - -30
226
What are chemoreceptors sensitive to?
CO2
H
O2
227
inspiration has to be triggered by
muscles
228
expiration is mostly
passive recoil
229
what breathing control centers are in the Medulla
DRG (dorsal respiratory group)
VRG (ventral respiratory group)
230
what breathing centers are in the PONs
pneumotactic center
231
what does the DRG do
PURE inspiration
basic rhythm of quiet breathing
232
what does the VRG do
increased ventilation over quiet/resting
increases Expiration and inspiration
using muscle for expiration
233
what is the pneumotactic center responsible for
depth and rate of breathing
234
T/F the pneumotactic center is dormant during quiet breathing
false
always active
235
what triggers pneumotactic center
CO2
236
T/F we dont need a trigger for inspiration
false
must trigger inspiratory muscle
237
T/F we need a trigger for expiration
false
normally passive recoil
238
what part of respiratory cycle does emphysema screw up
expiratory, loss of recoil of lungs
238
when is electrical activity high in the diaphgram
inspiration (makes sense since this is contraction and expiration is relaxation)
239
in inspiration pleural pressure is __________ and electrical activity is ________
decreased
increased
240
in expiration pleural pressure is __________ and electrical activity is ________
increased (to baseline)
decreased (to baseline)
241
Where does the DRG receive input from?
chemo and mechanoreceptors
pneumotactic center
242
what is the inspiratory ramp signal
-signal transmitted to inspiratory muscle increases steadily for 2-3 second during quiet respiration
-ramp allows for a steady increase in volume rather than short gasps
243
inspiratory phase is (shorter/longer) than expiratory phase
Shorter
244
what makes the ramp effect
transmission of impulse
length of time of muscle activation
245
what is the role of the pneumotactic center
regulates DRG
controls rate and duration of inspiration
depth and speed or breathing
246
when is VRG activated
during times of increased respiratory need (exercise)
when forced expiration needed
247
when is VRG inactive
quiet respiration
248
what respiratory control center stimulates forced expiration
VRG
249
why is CO2 the trigger for respiration
has a smaller range of intravascular levels (40 arterial, 46 tissues)
250
increased CO2 (increases/decreases) respiratory depth and rate
increases
251
what is feedforward control
proprioceptors in joints/muscles can trigger increased respiration in response to increased movement
252
is feedforward control CO2 controlled
no
253
what fine-tunes the feed forward control
negative feedback
254
what nerve primarily carries mechanoreceptor impulses
vagus nerve
255
Where are pulmonary stretch receptors located?
airway smooth muscle in bronchi and bronchioles
256
what stimulates the pulmonary stretch receptors to fire
increased pressure in lungs (stretch)
257
What is the Hering-Breuer reflex?
reflex triggered to prevent over-inflation of the lungs.
Pulmonary stretch receptors present in the smooth muscle of the airways respond to excessive stretching of the lung during large inspirations.
258
what prevents overstretch of lungs during inspiration
Hering Breuer reflex of pulmonary stretch receptors
259
When is the Hering-Breuer reflex activated?
3x tidal volume (1500 ccs)
260
where are irritant mechanoreceptors found
epithelium of larger conducing airway
261
what triggers irritant receptors
particulate matter causing inflammation mediators (histamine, serotonin, prostaglandins)
262
what are the conducting airways
trachea, bronchi, bronchioles, terminal bronchioles
263
do conducting airways have air exchange
NO
264
what is response of irritant receptor activation
cough/sneeze
bronchoconstriction
265
what illnesses can irritant receptor activation cause issues in
asthma, emphysema
266
what cells does asthma cause issues with
goblet cells
267
where are the J receptors located
in/near alveoli- juxtapulmonary receptors
268
What do J receptors respond to?
acute congestion/edema
damage
269
what is response of J receptors
stimulates increased ventilation
270
what do the peripheral chemosensors respond to
CO2, H+, O2 (in that order)
271
What do the central chemoreceptors respond to?
primarily
CO2
secondarily
H
272
what is goal of all mechanoreceptors
increase ventilation
get O2 to body
273
when do chemo receptors respond to PO2
<60mmHg
274
T/F the blood brain barrier is highly permeable to H and HCO3
False
its poorly permeable
275
T/F metabolic acidosis significantly lower CSF pH
False
276
T/F respiratory acidosis significantly lower CSF pH
true
277
T/F the blood brain barrier is permeable to CO2
True
its a gas passes freely
278
what happens after CO2 crosses BBB
combines with water and becomes H and HCO3 in CSF
279
how long does it take the kidney respond to acid/base imbalances
2-3 days
280
how long does it take the lungs to respond to acid/base imbalances
immediate
281
what triggers the respiratory centers in the medulla
H+ in CSF
282
where does H+ in CSF come from
CO2 crossing BBB
283
where do peripheral chemoreceptors send their signals
DRG
284
what kind of oxygen do peripheral chemoreceptors read
PaO2,
not total oxygen content
285
what else are peripheral chemoreceptors sensitive to
cyanide
arterial pressure <60
286
what chemo receptors sense hypoxia
only peripheral
287
hyperventilation leads to (hypo/hyper) capnia
hypo
resp alk
288
T/F hyperpnea during exercise causes abnormal blood CO2
False
increased metabolism creates CO2, no no hypocapnia
289
hypoventilation leads to (hypo/hyper) capnia
hyper
resp acidosis
290
what can trigger hyperventilatoin
hypoxia
291
when is hyperventilation triggered by hypoxia
PaO2 < 60 mmHg,
causes decreased PaCO2 and high pH in short term
292
how does body respond to high altitude
hypocapnia initially increases CSF pH
overtime bicarb is excreted by the kidneys, allowing an increase in ventilation
293
do arterial O2, CO2 and pH change during exercise
NO
294
what are bodies fluid chemical buffers for hydrogen ions
Rapid but temporary
Bicarbonate
proteins
ammonia
phosphate
295
how do the lungs regulate hydrogen ions
rapid
respond to acidosis by increasing ventilation, thus eliminating CO2 and decreasing pH
296
how do the kidneys regulate hydrogen ions
slow, powerful
eliminate non-volitile acids
secretes H+
reabsorbs HCO3-
generates new HCO3
297
what is the most important ECF buffer?
formula?
bicarb
H2O+ + CO2 <-> H2CO3 <-> H+ + HCO3
298
what is the phosphate renal buffer
formula
phosphate
HPO4- + H+ <-> H2PO4- (phosphoric acid)
299
what is the ammonia renal buffer formula
ammonia
NH3 + H+ <-> NH4+ (ammonium)
300
what is an important intracellular buffer
proteins
H+ + Hb <-> HHb (hemoglobin)
301
where does 60-70% of buffering occur
cells
302
what determines the effectiveness of a buffer system
-concentration of reactants
-pK of system and pH of body fluids
303
what is pK
concentration of H+ per pH reading. balanced is pK=6.1
304
know the bicarb buffer equation
H2O+ + CO2 <-> H2CO3 <-> H+ + HCO3
305
what enzyme has to be present to convert H2O and CO2 to carbonic acid and vise versa
carbonic anhydrase
306
what is the most important buffer in ECF
bicarbonate buffer system
307
what organs closely regulate the bicarb formula
lungs- CO2
kidney- HCO3-
308
How do the lungs regulate pH?
increased H+ -> increased alveolar ventilation -> decreased pCO2
309
How do kidney regulate pH?
eliminate non-volatile acids (sulfuric acid, phosphoric acid)
filter bicarb (HCO3)
secretion of H+
reabsorption of bicarb
production of new bicarb
excretion of bicarb
310
for every HCO3 reabsorbed, the must be a __________ secreted
H+
311
where is most bicarb reabsorbed in the kidney
proximal tubule- 85%
thick ascending loop of henle- 10%
late distal tubule - 4.9%
collecting duct- .1%
312
how is sodium bicarb reabsorbed/excreted in proximal tubule and thick loop of henle
1) Na+ H+ pump exchange takes Na from tubule, puts H into tubule
2) carbonic acid formed
3) carbonic acid broken into CO2 and H2O
4)H2O excreted
5) CO2 reabsorbed into cell
6) CO2 combines with H2O in cell with carbonic anhydrase to form H2CO3 (carbonic acid)
7) H+ breaks off from carbonic acid
8) HCO3 (bicarb) reabsorbed into blood
9) H+ is available to exchange for another Na (step one)
313
how does aldosterone affect renal pH control
causes sodium uptake and H+ secretion (Na/H pump)
314
how is bicarb reabsorbed and H secreted in intercalated cells of late distal and collecting tubules
1) CO2 absorbed from blood
2) CO2 combines with water in intercalated cell to form carbonic acid
3) carbonic acid dissociates into HCO3 and H+
4) HCO3 is reabsorbed
5) H is secreted (into urine) by use of ATP or with a K exchange
315
increase CO2 = ___________ H+ secretion
increased
316
what is increased CO2 in body leading to acidotic state
resp acidosis
317
increased extracellular H = _____________ H+ secretion
increased
318
what causes an increase in tubular fluid buffers to increase H+ secretion
respiratory or metabolic acidosis
319
what conditions cause you to increase H+ secretion and HCO3 reabsorption
increased PCO2 (resp acidosis)
increased H+ and decreased HCO3 (metabolic acidosis)
increase in aldosterone
increased angiotensin 2 (increases aldosterone)
decreased ECF volume
hypokalemia
320
what conditions cause a decrease in H secretion and HCO3 reabsorption
decreased PCO2
decreased H+ and decreased HCO3 (metabolic alkalosis)
decrease in aldosterone
decreased angiotensin 2 (decreases aldosterone)
increased ECF volume
hyperkalemia
321
what is renal compensation for acidosis
increased H secretion
increased HCO3 reabsorb
produce new HCO3
322
what is kidneys response to alkalosis
decreased H secretion
decreased HCO3 reabsorb
loss of HCO3 in urine
323
in acidosis when H+ is being in secreted what must be present in urine
buffers, limited to the amount of free H kidneys can excrete
324
what is the minimum pH of urine before damage occur
4.5, this is why we need buffers for H excretion
325
what occurs when NaHPO4- acts as a buffer in urine
one Na used to exchange for H for excretion, forms with NaHPO4- as a buffer
Turns NaHPO4 to H2PO4, phosphoric acid
new HCO3 formed in cell to be reabsorbed into blood
326
what is NH3
ammonia
327
what is NH4
ammonium
328
where is NH4 secreted in nephron
proximal,
thick loop of henle,
distal tubules
329
where does glutamine come from
amino acid metabolism from liver
330
what does glutamine break down into
2 bicarbs
2 ammonium
331
how does ammonium get removed from tubular cell
Na+ /NH4+ exchange pump (NH4 excreted)
332
how is H+ and NH3 buffered in collecting tubules
NH3 is permeable, freely passes through tubular cell wall into tubular lumen
CO2 froms with H2O to form bicarb in cell, with H+ as byproduct
H+ excreted with ATP from tubular cell
NH3 and H form NH4, excreted with Cl- to form ammonium chloride
333
what causes acidosis (pH <7.4)
metabolic: decreased HCO3
respiratory: increased pCO2
334
what causes alkalosis (pH>7.4)
metabolic: increased HCO3
respiratory: decreased pCO2
335
what is normal body pH
7.35-7.45
336
what is normal ratio of HCO3 to CO2
20:1
337
what is the pH range that is compatible with life
6.8-7.8
338
acid base imbalance chart
339
what is Respiratory acidosis:
pH:
Primary disturbance:
Compensation:
pH: low
PD: increased CO2
Comp: renal acid excretion, bicarb reabsorption
340
what is metabolic acidosis:
pH:
Primary disturbance:
Compensation:
pH: low
PD: decreased HCO3
Comp: hyperventilation to cause low CO2
341
what is Respiratory alkalosis:
pH:
Primary disturbance:
Compensation:
pH: high
PD: decreased CO2
Comp: decreased renal acid excretion (retain more H) increased bicarb excretion (B intercalated cells)
342
what is metabolic alkalosis:
pH:
Primary disturbance:
Compensation:
pH: high
PD: increased HCO3
Comp: hypoventilation with increased CO2
343
what is normal ABG HCO3
22-26 mEq/L
344
what is BG interpretation for
pH: 7.12
PCO2: 50
HCO3: 18
mixed acidosis
345
what is BG interpretation for
pH: 7.6
PCO2: 30
HCO3: 29
mixed alkalosis
346
what is measured in anion gap
Cation
Na +
Anion
Cl-
HCO3-
347
in body fluids anions should be ___________ cations
equal to
348
what is a normal anion gap
8-16
349
how do you calculate anion gap
Na-(Cl+HCO3)
350
when do we use anion Gap
metabolic acidosis
351
what are the unmeasured anions
proteins
sulfates,
ketones,
phosphates,
lactate,
352
what does an increased anion gap tell us
an increase in the unmeasured anions
353
what is a metabolic acidosis with a normal anion gap
hyperchloremic metabolic acidosis
(increased Cl, decreased HCO3)
354
what is metabolic acidosis with an increased anion gap
(so Cl normal, HCO3 low)
normochloremic metabolic acidosis
-diabetic ketoacidosis
-lactic acidosis
-salicylic acid
355
what is BG interpretation for
pH: 7.2
PCO2: 55
HCO3: 26
resp acidosis
356
what are causes of respiratory acidosis
brain damage
pneumonia
emphysema
lung disorders
357
what is BG interpretation for
pH: 7.5
PCO2: 40
HCO3: 30
metabolic alkalosis
358
What are the causes of metabolic alkalosis?
increased base intake (NaHCO3)
vomiting gastric acid
mineralcorticoid excess (aldosterone)
overuse of diuretics (except carbonic anhydrase inhibitors)
359
what is BG interpretation for
pH: 7.34
PCO2: 29
HCO3: 15
metabolic acidosis (resp compensation)
360
what is BG interpretation for
pH: 7.49
PCO2: 48
HCO3: 35
metabolic alkalosis (resp compensation)
361
what is BG interpretation for
pH: 7.34
PCO2: 60
HCO3: 31
respiratory acidosis (metabolic compensation)
362
what is BG interpretation for
pH: 7.62
PCO2: 20
HCO3: 20
respiratory alkalosis (metabolic comp)
363
what is BG interpretation for
pH: 7.09
PCO2: 50
HCO3: 15
mixed acidosis
364
how does the kidney regulate the body fluid acidity
bicarbonate
365
what is carbonic acid
H2CO3
366
what actually drives respiration
H+ ions around pons in CSF
367
where do loop diuretics work
thick ascending loop of henle
368
what are the loop diuretic examples
furosemide
bumetanide
ethacrynic acid
369
which transporter does the loop diuretic work on
1 na, 2 cl and 1 K transporter
"triple transporter"
370
what do loop diuretics bind up to have effect
2 chloride on triple transporter
371
what does loop diuretic cause excretion of from triple transporter
Na
K
Cl
372
where do thiazide diuretics work
early distal tubule- on sodium chloride transporter
373
what does thiazide diuretic inhibit
sodium chloride transporter- so sodium stays in lumen and draws water into lumen for excretion
374
what are some aldosterone antagonists
spironolactone, eplerenone
375
what are some sodium channel blockers
amiloride, triamterene
376
how do osmotic diuretics work and where?
proximal convoluted tubule
pull water in to dilute the extra concentrates in the lumen
377
where do loop diuretics work
thick ascending loop of henle
block Cl on triple symporter, so K and Na stay in the lumen to be excreted along with Mg and Ca
378
where do thiazide diuretics work
distal convoluted tubule
blocks the Na Cl sympoter
379
where do K sparing diuretics work
collecting duct
block aldosterone and Na channels on Na K antiporter
379
what are types of K sparing diuretics
Na channel blockers ( amiloride)
Aldosterone antagonist (spironolactone)
380
define pulmonary ventilation
inflow and outflow of air between the atmosphere and lung alveoli
381
how can lungs be contracted
- downward and upward movement of the diaphragm to lengthen or shorter the chest cavity
-elevation and depression of the ribs to increase or decrease AP diameter
382
what is considered quiet breathing
the movement of diaphragm to expand lungs
383
What is minute respiratory volume
Total amount of new air moved into the respiratory passages each minute
Min resp vol= tidal vol + resp rate per min
384
What is a normal min resp vol
6L/min
385
What are the lung volumes
Tidal volume
Inspiratory residual volume
Expiratory reserve volume
residual volume
386
What are the four lung capacities
Vital lung capacity (tv+ irv+ erv)
Inspiratory capacity (tv+irv)
Functional residual capacity
Total lung capacity
387
When bicarb is being brought into the RBC through a transporter what is being pushed out
Chloride molecule
388
How much non-volatile acid produced a day
~60-80 mmol/day
389
What are the important renal tubular buffers
Phosphate
Ammonia
390
Renal regulation of acid base
Eliminate non volatile acids
Filter bicarb
Reabsorb bicarb
Produce new bicarb
Excrete bicarb
Secrete H ions
391
How is glutamine formed
From metabolism of amino acids
392
What is the systolic and diastolic for systemic circ
93/2
393
What’s the average MAP for pulmonary capillaries
10
394
What happens to pulmonary resistance as CO increases? Why?
Decreases
Recruitment and distention
395
Reduced airflow to a particular region of the lung leads to:
Reduced blood flow to that area
Blood shunts to alveoli that has airflow
396
Generalized hypoxemia=
Generalized vasoconstriction
Leads to high pressures backing up in the heart
397
What’s the interstitial osmotic pressure
14 mmHg
398
Colloid osmotic pressure ____ and hydrostatic pressure _____
Pulls
Pushes
399
How does smooth muscle tone affect flow
PNS causes constriction and increased mucous production
SNS causes dilation and increased fluid secretion
Environmental insults can cause vasoconstriction
High CO2 causes dilation of resp tract
400
How does turbulence influence resistance
Increases resistance
Branching airways decreases resistance
401
Define Bohr effect
CO2 and H are affecting the affinity of Hb for oxygen
402
Define Haldane effect
Oxygen is affecting the affinity of Hb for CO2 and H
403
What airway generations are the conducting zone
0 trachea
1-2/3 bronchi
4-7 bronchioles
8-16 terminal bronchioles
404
What airway generations are the respiratory zones
17-18 respiratory bronchi
19-21 alveoli duct
22-23 alveoli sac
405
Physiological dead space is about ____ of ____ _____ in healthy people
1/3
Tidal volume
406
How can you determine alveolar ventilation
Measure CO2 output
407
Equal pressure point
The pressure inside the alveolar duct/respiratory bronchi is = the pressure in the pleural cavity
408
What factors affect the rate of diffusion in a fluid
Solubility of gas in the fluid
Cross sectional area of the fluid
Distance through which the gas must diffuse
Molecular weight of the gas
Temp of the fluid
409
The O2 conc/ partial pressure is controlled by
Rate of absorption of O2 into the blood
Rate of entry of new O2 into the lungs
410
What does the pneumotaxic center do
Controls the “switch off” point in the inspiratory ramp
Controls the filling phase of the lung cycle
411
When does dead space occur
When there is ventilation but no perfusion
412
When does a shunt occur
When there is perfusion but no ventilation
413
What is a normal FEV1/FVC%
80%
Airway obstruction is 47%
414
What causes chronic pulmonary emphysema
Infection
Obstruction
Loss of parenchyma
415
What are consequences of COPD
High airway resistance
Decrease diffusing capacity
Pulm hypertension
416
Consequences of pna
Significant decrease in arterial hgb saturation
417
Hypoxia is sensed by
Peripheral chemoreceptors
418
Define hypoxia
Low O2 supply at lungs and tissue
419
Define hypoxemia
Low PaO2
Low blood O2
420
Control of ramp signal
Rate of increase
Control of limiting point (drop off point)
