RESPIRATORY Flashcards
1
Q
The volume inspired or expired with each normal breath
A
Tidal volume (Vt)
2
Q
Volume that can be inspired over and above the tidal volume
used during exercise
A
Inspiratory reserve volume (IRV)
3
Q
The volume that can be expired after the expiration of a tidal volume
A
Expiratory reserve volume
4
Q
The vlume that remains in the lungs after a maximal expiration
cannot be measured by spirometry
A
Residual volume
5
Q
2 types of dead space
A
Anatomic
Physiologic
6
Q
The volue of the conducting pathways
A
Anatomic pathway (approximately 150 mL)
7
Q
functional measurement
defined as the volume of the lungs that does not participate in gas exhange,
approximately equal to the anatomic dead space in normal lungs.
A
Physiologice dead space
- may be greater than the anatomic dead space in lung diseases in twhich there are V/Q defects
8
Q
Physiologic dead space can be calcutated by this equation
A
9
Q
A
10
Q
Lung volumes and capacity
A
11
Q
Minute ventilation is expressed as _______
A
Minute ventilation = Vt x RR
12
Q
Alveolar Ventilation (VA) is expressed as ________
A
VA = (VT - VD) x RR
13
Q
The sum of tidal volume and IRV
A
Inspiratory capacity
14
Q
Sum of ERV and RV
the volume remaining in the lungs after a tidal volume is expired
Includes RV, cannot be measured by spirometry
A
Functional residual capacity (FRC)
15
Q
Sum of tidal volume, IRV, ERV
the volume of air that can be forcibly expired after a maximal inspiration
A
Vital capacity, or forced vital capacity
16
Q
Sum of all four lung volumes.
The volume in the lungs after a maximal inspiration
includes RV, so it cannot be measured by spirometry
A
Total lung capacity
17
Q
the volume of air that can be expired in the first second of a forced maximal expiration
A
Forced expiratory volume (FEV1)
normally 8% if the forced vital capcacity
(FEV1 / FVC) = 0.8
18
Q
in obstructive disease, such as asthma and COPD, FEV1 and FVC are ______
A
Reduced
- FEV1 is reduced more than FVC
- FEV1/FVC = decreased
19
Q
In restrictive lung disease, such as fibrois, both FEV1 and FVC are _______
A
Reduced
- FVC is reduced more
- FEV1/FVC = increased
20
Q
The most imporatnt muscle of inspiration
A
Diaphragm
- when the diaphragm contracts, the abdominal contents are pushed downward, and the ribs are lifted upward and outward, increasing the volume of the thoracic cavity
21
Q
Not used for inspiration during normal quiet brething
used during exercise and in respiratory distress
A
External intercosatal and accessory muscles
22
Q
Expiration is (active or passive)
A
Passive
23
Q
Push the diaphragm up and push air out of the lungs
A
Abdominal muscles
24
Q
Pull the ribs downward and inward
A
Internal intercostal muscles
25
Analogous to capacitance in the CVS
Distensibility of the lungs and chest walls
Compliance
26
Compliance is ______ related to elastance
Inversely
27
Compliance of the lungs
* Transmural pressure is alveolar pressure minus intrapleural pressure
* Whenthe pressure outside the lungs is negattive, lung lungs EXPAND and lung volume INCREASES
* In the middle range of pressures,
* Compliance is GREATEST and the lungs are most distensible
* At high expanding pressures
* Compliance is lowest, the lungs are least distensible and the curve Flattens
28
Inflation of the lungs follows a different curve than deflation of the lungs (expiration); this difference is called \_\_\_\_\_\_\_\_\_\_\_
hysteresis
* due to the need to overcome surface tenson forces when inflating
29
Compliance of the combined lung-chest wall system
* Compliance of the lung chest wall system is less than of the lungs alone or the chest wall along (slope is flatter)
* At rest, Lung volume is at FRC and the pressure in the airways and lungs is qual to atmospheric pressure (0)
* collapsing force of the lungs
* expanding force of the chest wall
* interpleural pressure is **NEGATIVE**
30
In a patient with emphysema, lung compliance is \_\_\_\_\_\_\_\_\_\_\_\_\_
Increased
* higher FRc
* patient's chest becomes barrel shaped
31
In a patient with fibrosis, lung compliance is \_\_\_\_\_\_\_
Decreased
* lower FRC
32
Results from the attractive forces between liquid molecules lining the alveoli at the air liquid interface
Surface tension
33
Cretaes a collapsing pressure that is directly proportional to surface tension and iversely proportional to alveolar radius
Laplace's Law
34
Large alveoli have ______ collapsing pressures and are easy to open
low
35
Small alveoli have ______ collapsing pressure
high
* In the absence of surfactant, the small alveoli have a tendency to collapse (atelectasis)
36
Reduces surface tension by disrupting the intermolecular forces between liquid molecules.
Increases co,piance
Surfactant
37
Surfactants are synthesized by
Type II alveolar cells
38
Surfactants are primarily cosnsists of the phospholipid
dipalmitoylphosphatidylcholine (DPPC)
39
In the fetus, surfactant synthesis is variable. Surfactant may be present as early as week ______ and is almost always present by gestation week \_\_\_\_\_\_
24
35
40
LEcithin: sphingomyelin ration greater than _____________ in amniotic fluid reflects mature levels of surfatant
2:1
41
driven by and is directly proporional to the **pressure difference** between the mouth(or nose) and the alveoli
Airflow
* Inversely proportional to airway resistance.
42
Resistance of the airways is described by \_\_\_\_\_\_\_\_\_\_\_\_
Poiseuille's law
* Notice the powerful inverse fourth power relationship between resistance and the size (radius) of the airway
43
Mahor site of airway resistance is the \_\_\_\_\_\_\_\_-
Medium sized bronchi
* Why not the smallest airways?
* Parallel arrangemetn
44
Factors that change airway resistance
* Contraction or relaxation of bronchial smooth muscles
* Lung volume
* Viscosity or density of inpired gas
45
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_stimulation, irritants, and the slow reacting substancce of anaphylaxis (asthma) constrict th airways, decrease the radius and inrease the resistance to airflow
Parasympathetic stmulation
46
\_\_\_\_\_\_\_\_\_-\_\_stimualtion dilate the airways via B2 receptors, increases the radius and decrease the resistance to airflow
Sympathetic
47
\_\_\_\_\_\_\_\_associated with greater traction on airways and decreased airway resistance.
high lung volumes
* patients with increased airway resistance learn to breathe at higher lung volumes to offset the high airway resistance associated with their disease
48
\_\_\_\_\_\_\_\_\_\_\_\_\_ are associated with less traction and increased airway resitance, even to the point of airway collapse
Low lung volumes
49
During a deep-sea dive, both air density and resistane to airflow are \_\_\_\_\_\_\_\_\_\_\_
increased
50
breathing a low density gas, such as helium __________ the resistance to airflow
reduces
51
Breathing cycle`
* At rest
* Alveolar pressure = atmospheric pressure
* Interpleural pressure is negative
* pressure can be measured in the esophagus
* Lung volume is FRC
* During inspiration
* Inspiratory muscles contract and cause the volume of the thorax to increase
* Lung volume increase, alveolar pressure decrease
* the pressure gradient causes air to flow
* Intrapleural pressure becomes more negative
* Lung volume increase by one Vt
* peak of inspiration
* Expiration
* Alveolar pressure becomes greater than atmospheric pressure
* Intrapleural pressure returns to its resting value
* lung volumes returns to FRC
52
During forced expiration, intrapleural pressure actually becomes \_\_\_\_\_\_\_\_\_\_\_\_\_
Positive
53
Obstructive disease in which expiration is impaired
Characterized by decreased FVC, decreased FEV1
Air trapping and increased FRC
Asthma
* decreased FEV1/FVC ratio
54
Combiantion of chronic bronchitis and emphysema
Obstrucive disese with increased lung compliance in which expiration is impaired
Decreased FVC and FEV1
Barrel shaped chest
Increased FRC
COPD
* Decreased FEV1/FVC ratio`
55
mild hypoxemia
normocapnia
Pink puffers
Primarily emphysema
56
Severe hypoxemia with xyanosis
hypercapnia
Blue bloaters
57
Restrictive disease with decreased lung compliance
decreased in all lung volumes
FEV1/FVC is increased or may be mormal
Fibrosis
58
Dalton's law of partial pressures
as exchange
Partial pressure = Total Pressure x fractional gas concentraion
* In dry inspired air, partial pressure of O2 can be calculated
* TP and Fractional O2 is 0.21
* PO2 = 760 mmHg x 0.21
* 160 mmHg
* Humidified tracheal air at 37 degrees, the calculation is odiefied to correct fot the partial pressure of H2O which is 47 mmHg
* 760 -47 mmHg = 713
* 713 x 0.21
* 150 mmHg
59
Approximately 2% of the systemic cardiac output bypasses the pulmonary circulation
Physiologic shunt
* the admixture of the venous blood and arterial blood makes the PO2 of arterial blood slightly lower han that of alveolar air
60
The amount of gas dissolved in a solution is proportional to its \_\_\_\_\_\_\_\_\_\_
Partial pressure
* The units of concentration of a dissolved gas are mL gas/100 mL blood
61
The diffusion rates of O2 and CO2 depend on the ____________ across the membrane and the area available fo diffusion
partial pressure difference
62
Gas diffusion across the alveolar-pulmonary capillary barrier occurs according to \_\_\_\_\_\_\_\_\_\_
Fick's law
* DL or lung diffusing capacity id the equivaent of permeability of the alveolar-pulmonary capilalry barrier and is proportional to diffusion coefficient of the gas and surface area and inversely proportional to thckness of the barrier
63
DL is measured with \_\_\_\_\_\_\_\_\_\_\_
carbon monoxide
64
DL ________ during excercise
Increases
* there are more open capillaries and thus more surface area for diffusion
65
DL ________ in emphysema
Decreases
* because of decreased suface area and in fibrosis and pulmonary edema (because of increased diffusion distance)
66
the gas equilibrates early along the length of the pulmonart capillary.
The partial pressure of the gas in arterial blood becomes equal to the partial pressure in alveoalar air
Perfusion- limited exchange
* Illustrated by N2O and O2 under normal conditions
* diffusion of the as in the arterial blood can be increased only if blood flow increases
67
The gas does not equilibriate by the time blood reacehs the end of the pulmonary capillary
The partial pressure difference of the gas between alveolar air and pulmonary capilalry blood is maintained.
Diffusion-limited exhange
* Diffusion contines as long as the aprtial pressure gradient is maintaine
68
Oxygen is carried in two forms:
Dissolved or bound
69
Hemoglobin
* globular protein of four subunits
* Ferrous state
* each subunit has a polypetide chain
* 2 alpha chains
* 2 beta chains
70
B chains are replace by y-cahins
Fetal hemoglobin
71
The oxygen affinity of fetal oxygen is _______________ than adult oxygen
Higher
* becaue of 2,3 diphosphoglycerate (DPG) binds less avidly to the y-chains of fetal hemoglobin
* Oxygen movement from mother to fetus is facilitated
72
Iron is in the Fe3+ state
Does not bind Oxygen
Methemoglobin
73
Causes sickle cell disease
The alpha subunits are normal and the B subunits are abnormal
hemoglobin S
* In the deoxygenated form, deoxyhemoglobin forms a sickle shaped rods that deform red blood cells (RBCs)
74
maximum amount of Oxygen that can be bound to hemoglobin
Limits the amount of oxygen that can be carried in blood
Measured at 100% saturation
Oxygen binfing capacity of hemoglobin
* expressed in units of mL O2/g hemoglobin
75
The total amount of oxygen carried in blood, including bound and dissolved oxygen.
depends on the hemoglobin concentration, the Oxygen binding capacity of hemoglobin, the PO2 and the P50 of Hgb
Oxygen content of blood
76
Hemoglobin combines rapidly and reversibly with oxygen to form\_\_\_\_\_\_\_
oxyhemoglobin
77
At a PO2 of 100mmHg(arterial blood) \_\_\_\_\_\_\_\_\_
hemoglobin is 100%saturated; oxygen is bound to all four heme groups on all hemoglobin molecules
78
At PO2 of 40 mmHg \_\_\_\_\_\_\_
hemoglobin is 75% saturated, which means that on average, 3/4 heme groups on eah hemoglobin molecule have O2 bound
79
at PO2 of 25 mmHg \_\_\_\_\_\_\_\_\_\_
Hemoglobin si 50% saturated
The PO2 at 50% is the P50. 50% saturation means that on average, 2/4 heme groups of each hemoglobin molecule have oxygen bound
80
The __________ shape of the HODC is the result of a chanfe in the affinity of hemoglobin as each successive oxygen molecule binds to a heme site
Sigmoid
(Positive coperativity)
* Binding of the first Oxygen molecule increases the affinity for the second molecule, and so forth
81
The HODC is almost flat when the PO2 is between \_\_\_\_\_\_\_\_\_\_\_\_\_\_
60-100 mmHg
Humans can tolerate changes in atmospheric pressure (and PO2) without compromising the oxygen carryng capacity of hemoglobin
82
Shifts to the right of HODC
* affinity of hemoglobin is decreased
* P50 is increased
* Inrease in PCO2 or decrease in pH
* **BOHR EFFECT**
* Increase in temperature (during exercise)
* Increase in 2,3 DPG concentration
* adaptation to chronic hypoxemia
83
Shift to the left of HODC
* affinity of hemoglbin to oxygen is increased
* P50 is decreased
* Decreased PCO2
* Increassed pH
* decreased temperature
* decreased 2,3-DPG
* HbF
* Carbon monoxide
84
Effect of carbon monoxide poisoning to the HODC
* CO competes for oxygen binding sites on hemoglobin
* the affnitity for CO is 200x
* shify to the left
85
Decreased in arterial PO2
caused by deceased PAO2, diffusion defect, V/Q defects, and right to left shunts
Hypoxemia
86
can be used to compare causes of hypoxemia
A-a gradient
87
Normal A-a gradient is \_\_\_\_\_\_
0-10 mmHg
88
A-a gradient is _________ if Oxygen does not equlibriate between alveolar gas and arterial blood
Increased
* Diffusion defect
* V/Q defect
* Right to left shunt
* PAO2 is greater the PaO2
89
Decreased oxygen delivery to the tissue
caused by decreased blood flow, hypoxemia, decreased hemoglobin concentration, CO poisoning, and cyanide poisoning
hypoxia
* Oxygen delivery
* O2 delivery = Cardiac output x Oxygen content of blood
90
oxygen content of blood depends on \_\_\_\_\_\_\_\_\_
* Oxygen binding capacity of hemoglobin
* PO2
91
Cause of hypoxia
92
Is a growth factor that is synthesized in the kidneys in response to hypoxia
Decreased Oxygen delivery to the kidney causes increased production of hypoxia inducible facto 1a
Erythropoeitin
93
Produced in the tissues and carried to the lungs in the venous blood
Carbon dioxide
* 3 forms
* Dissolved
* Carbaminohemoglobin
* **HCO3 (major form)**
94
In the RBCs, carbon dioxide combines with water to form H2CO3, a reaction cataluzed by \_\_\_\_\_\_\_\_\_\_\_
Carbonic anhydrase.
95
\_\_\_\_\_\_\_\_\_leaves the RBCs in exchange for Chloride (chloride shift) and is transported to the lungs in the plasma.
HCO3
96
H+ is buffered inside the RBCs by \_\_\_\_\_\_
Deoxyglobin
97
Pressures are much ______ in the pulmonary circulation than in he systemic circulation
* lower
98
Resistance is much ________ in the pulmonary circulation than in systemic circulation
lower
99
Cardiac output of the right ventricle is \_\_\_\_\_\_\_
Pulmonary blood flow
* equal to cardiac output of the left ventricle
* Although pressures int hepulmonary circulation are low, they are sufficient to pump the cardiac output because resistance of the pulmonary circulation is proportionately low
100
When a person is _____ blood flow is nearly uniform throughout the lung
supine
101
When a peron is ____ blood flow is unevenly distributed
standing
* Due to the effect of gravity
* lowest at the apex (zone 1)
* highest at the base (zone 3)
102
Zone \_\_\_\_\_
Blood flow is lowest
Alveolar pressure \> arterial pressure \> venous pressure
1
* Th higher alveolar pressure may compress the capillaries and reduce the blood flow in zone 1
* This situation can occure if arterial BP is decreased as a result f hemorrhage or if alveolar pressure is increased because of PPP
103
Zone \_\_\_\_\_\_
blow flow is medium
Arterial pressure \> alveolar pressure \> venous pressure
2
* Moving down the lung, arterial pressure progressively increases because of gravitational effects on arterial pressure
* Arterial pressure is greater than alveolar pressure in zone 2, and blood flow is driven by the difference between arterial pressure and alveolar pressure
104
Zone\_\_\_\_\_\_\_
Blood flow is highest
Arterial pressure \> venous pressure \> alveolar pressure
3
* Moving down toward the base of the lung, arterial pressure is highest because of gravitational effects, and venous pressure finally increases to the point where it exceeds alveolar pressure
* Blood flow is driven by the difference between arterial and venous pressures as in most vascular beds
105
in the lungs, hypoxia causes \_\_\_\_\_\_\_\_\_
vasoconstriction
106
Right to left shunts
* normally occur to a small extent
* seen in TOF
* decrease in arterial PO2
* admixture of venous blood with arterial blood
107
Left to right shunts
* more common that right to left shunts
* pressure are higher on the left side of the heart
* congenital abdonormalities (PDA) or taumatic injuries
* Do not result in decrease in arterial PO2.
* PO2 will be elevated on the right side of the hear because there has been admixture of arterial blood with venous blood
108
Ration of alveolar ventilataion to pulmonary blood flow
V/Q ratio
* if the RR, tidal volume, cardiac output are normal, the V/Q is approximatly 0.8
* this V/Q results in an arterial PO2 of 100 mmHg and an arterial PCO2 of 40 mmHg
109
Blood flow or perfusion is \_\_\_\_a\_\_\_\_\_at the apex and \_\_\_\_\_b\_\_\_\_\_in the base
A: Lowest
B: Highest
* because of gravitational effects on arterial pressure
110
Ventilation is \_\_\_\_\_\_\_at the apex and \_\_\_\_\_\_\_at the base
A : lower
B: higher
* Gravitaional effect in the upright lung
* regional differences for ventialtion are not as great as for perfusion
111
V/Q ration is higher at the \_\_\_\_\_\_\_\_\_\_
Apex
112
If the airways are completely bloockedm the ventilation is zero. If bblood flow is normal then \_\_\_\_\_
V/Q is zero
Called a **shunt**
* no gas exchange in a lung that is perfused but not ventialted
* the PO2 and PCO2 of pulmonary capilalry blood will approach their values in mixed venous blood
* **increased A-a gradient**
113
If blood flow is completely bcoked, then the blood flow to that lung is zero. If ventilation is normal then \_\_\_\_\_
V/Q is infinite
Dead space
* No gas excahnge
* PO2 and PCO2 of alveolar gas wil aproach their values in inspired air
114
Sensory information (PCO2, lung stretchm irritants, muscle spindles, tendons, and joints) is coordination in the \_\_\_\_\_\_\_
Brain stem
115
Medullary respiratory center is located in the \_\_\_\_\_\_\_\_\_\_\_\_
reticular formation
116
primarily for inspiration and generates the basic rhythm for breathing.
Dorsal respiratory group
117
Input to the dorsal respiratory group comes from the ____ and _____ nerves
Vagus and Glossopharyngeal
* Vagus = from peripheral chemoreceptors and mechanoreceptors
* Glossopharyngeal nerve = from peripheral chemoreceptors
118
Output from the dorsal respiratory group travels via \_\_\_\_\_\_\_\_\_\_\_\_\_\_
Phrenic nerve
119
Priamarily responsible for expiration
not active during normal, quiet breathing, when expiration is passive
Ventral respiratory group
120
Apneustic center is located in the \_\_\_\_\_\_\_
lower pons
121
Stimulates inspiration, producing deep and prolonged inspiratory gasp
apneustic center
122
Pneumotaxic center is located in the \_\_\_\_\_\_\_
upper pons
123
Inhibits inspiration and, therefore regulates inspiratory volume and respiratory rate
Pneumotaxic center
124
Central chemoreceptors in the medulla are sensitive to the _____ of the CSF.
pH
125
Decrease in the pH of the CSF produce ________ in breathing rate
increase (hyperventilation)
126
The _______ are located at the bifurcation of the common carotid arteries
Carotid bodies
127
The ______ are located above the aortic arch
Aortic bodies
128
Decrease ina rterial PO2 stimulate the peripheral chemoreceptors and __________ breathing rate
Increase
129
PO2 must decrease to ________ before breathing is stimulated.
\<60 mmHg
130
\_\_\_\_\_\_\_\_\_\_ in arterial PCO2 stimulate peripheral chemoreceptors to increase breathing rate
Increase
* Potentiate the stimulation of breathing caused by hypoxemia
131
The respnse o the peripheral chemoreceptors is _______ important than is the responsse of the central chemoreceptors to CO2 or H+
less
132
In \_\_\_\_\_\_\_\_\_\_\_\_\_.(Metabolic/respiratory ; acidosis/alkalosis) breathing rate is increased
Metabolic acidosis
133
located in the smooth muscle airways
when these receptor ae stimulatedm they produce a decrease in breathing frequency
Lung stretch receptors
| (HERING-BREUER REFLEX)
134
Located between the airway epithelial cells
stimulated by noxious substances
Irritant receptors
135
Located in the alveolar walls, close to the capillaries.
Engorgement of the pulmoanry capillaries, such as that may occur with left heart failure stimulates this receptors, which then cause rapid, shallow breathing
J receptors
136
activated during movement of limbs
Involved in the early stimulation of breathing during exercise
joint and muscle receptors
137
Summary of respiratory response to exercise
138
Summary of adaptation during High altitudes
139
The mean values for PO2 and PCO2 \_\_\_\_\_\_\_\_\_\_\_\_\_during exercise
Do not
* arterial pH does not change during moderate exercise, although it may decrease during strenuous excercise because of lactic acidosis
140
Venous PCO2 ______ during exercise beause the excess CO2 produced by exercising muscle is carried to the lungs in venous blood
Increases
141
Pulmonary blood flow ________ during exercise
Increases
* because cardiac out increases duringe xercise. As a result, more pulmonary capillaries are perfused, and more gas exchanged occurs.
* Decrease in the physiologic dead space
142
Alveolar PO2 is ____ at high altitude
Decreased
* barometric pressure is decreased.
143
Hyperventilation produces respiratory alkalosis, which can be treated by administering \_\_\_\_\_\_\_\_
Acetazolamide
144
2,3 DPG conentrations are _______ in high altitudes
Increased
145
\_\_\_\_\_\_\_\_\_\_\_\_\_\_is a result of hypoxia. there is increase in pulmonary arterial pressure, increased work of the right sisde of the heart against the higher resistance, and hypertrophy of theright ventricle
Pulmonary vasoconstriction
