Respiratory System Flashcards
(151 cards)
1
Q
upper airway muscles (33)
A
active during inspiration, keep airway open
nasal and oral cavities, pharynx, larynx (vocal cords)
Trachea
Lungs
- bronchi –> bronchioles –> alveoli
smooth muscle and connective tissue
pulmonary circulation
2
Q
Sleep apnea
A
reduction in upper airway path during sleep. Airflow is blocked.
caused by loss of muscle tone, anatomical defects
3
Q
Risk factors of sleep apnea
A
Lack of excitatory drive - reduction in muscle tone
4
Q
Filtering Action regions
A
conducting zone - mucus-producing (goblet) cells and ciliated cells
trap and remove inhaled particles
muco-cilliary escalator
5
Q
Role of goblet cells and ciliated cells
A
Trap inhaled particles and remove them. Prevent it from reaching respiratory zone
6
Q
SOL layer
A
low density. Free cilia movement
CILIATED cells that have free movement
7
Q
GEL layer
A
Goblet cels (mucous)
high viscosity and elastic properties
traps inhaled particles
8
Q
Removal of mucous
A
cilia movements
downward (nasopharynx)
upward (trachea)
eliminated through esophagus
9
Q
Smoking affect on cilia and goblet cells
A
chemicals/tar effect cilia movement, preventing the removal of particles
10
Q
Where are macrophages located
A
Alveoli
Last defence to inhaled particles
11
Q
Pulmonary fibrosis
A
silica duct and abestos
lungs cannot expand due to collagen buildup over time
12
Q
Spirometry
A
Pulmonary function test
rate of insp and exp air
measure volume of air inspired and expired by the lungs
AMOUNT AND RATE OF AIR BREATHED IN AND OUT OVER TIME
13
Q
Atelectasis
A
complete or partial collapse of lung (or lobe of lung)
Occurs when alveoli become delated/flat
14
Q
Can you measure residual lung volume?
A
NO it cannot be measured via spirometry
15
Q
Tidal volume
A
volume of air moved IN or OUT of respiratory tract during each ventilation cycle
16
Q
inspiratory reserve volume
A
additional volume of air that can be forcibly inhaled following NORMAL RESP
simply inspire maximally, MAXIMAL POSSIBLE INSPIRATION
17
Q
expiratory reserve volume
A
additional volume of air that can be forcibly exhaled following normal expiration
simply expire maximally MAXIMUM VOLUNTARY EXPIRATION
18
Q
residual volume RV = FRC - ERV
A
the volume of air remaining in the lungs after a MAXIMAL EXPIRATION. cannot be expired at all (no matter what)
RV = FRC - ERV
19
Q
Capacities
A
SUM of two or more lung volumes
20
Q
VC = TV + IRV + ERV
A
VITAL CAPACITY - maximal amount of air that can be forcibly exhaled after maximal inspiration
21
Q
IC = TV + IRV
A
INSPIRATORY CAPACITY - maximal volume of air that can be forcibly exhaled
22
Q
FRC = RV* + ERV
A
FUNCTIONAL RESIDUAL CAPACITY - volume of air remaining in the lungs at the end of a normal expiration
cannot be measured by spirometry
23
Q
TLC = FRC + TV + IRV = VC + RV*
A
TOTAL LUNG CAPACITY - the volume of air in the lungs at the end of a maximal inspiration
cannot be measured by spirometry
24
Q
Lung volume
A
Tidal volume - 0.5 L
25
Flow (calculation)
26
Total/minute ventilation
total amount of air moved into the respiratory system per minute
Total/minute ventilation = TV x resp frequency = 0.5L x 15bpm = 7.5L/min
27
Alveolar ventilation (Va)
amount of air moved into alveoli per minute
depends on the anatomical dead space - constant, not available for gas exchange
AV = (0.5 - 0.15) L x 15/min = 5.25 L/min
28
Which sis more effective - DEEP breathing or INCREASED RATE (shallow)?
Deep breathing - higher alveolar ventilation
29
FEV1
FORCED EXPIRATORY VOLUME in 1 sec
health person can empty most air out of their lungs in one second
30
FVC
FORCED VITAL CAPACITY
amount of air that is blown out in one breath after max inspiration as fast as possible
31
Spirometry Test Patterns (3)
1. normal (age, gender, weight, height)
2. obstructive (difficulty exhaling - asthma)
shortness of breath, air comes out slowly
3. restrictive (difficulty fully expanding - fibrosis, ALS, MS)
stiffness in lungs
32
Helium dilution technique
helium is insoluble in blood, EQb after a few breaths, Measure the concentration at the end of expiratory effort
measures communicating gas or ventilated lung volume
33
Mechanics of Ventilation
34
Static properties of lung (mechanics of ventilation)
```
NO AIR IS FLOWING
maintains chest wall volume
Intrapleural ressuer (Pip), transpulmonary pressure (Ptp)
```
35
Dynamic properties of lung (mechanics of ventilation)
LUNGS ARE CHANGING VOLUME
air flows in and out
permits airflow
Alveolar pressure (Palv)
36
Boyle's Law
for a fixed amount of an ideal gas; fixed temperature
Pressure and volume are INVERSELY proportional
P1V1 = P2V2 (contant T)
gas molecules are in constant motion, creating pressure:
EXPIRATION: decrease volume, increased pressure (alv)
INSPIRATION: increased volume, decreased pressure (alv)
37
Ventilation
exchange of air between the atmosphere and alveoli
Bulk flow: gas moves from HIGH pressure to LOW pressure
F = deltaP / R
deltaP ---> (Palv-Patm)
38
What creates pressure
movement of gas molecules in a container
39
How ia airflow created
change in volume and pressure produces airflow
pressure difference is generated, air moves via bulk flow HIGH to LOW pressure
F = deltaP / R
40
Elastic recoil
interaction between lung and thoracic caste determines lung volume
Lungs tend to collapse due to elastic recoil
chest wall - pulls thoracic cage outward due to elastic recoil
EQb --> inward recoil balanced with outward recoil
41
Intrapleural Pressure (Pip)
Intrapleural fluid - reduces friction of lung against thoracic wall during breathing
PRESSURE IN THE PLEURAL CAVITY
always subatmospheric
if Pip = Palv ---> lungs would collapse
42
Transpulmonary pressure
FORCE RESPONSIBLE FOR KEEPING ALVEOLI OPEN
grater than 0 to keep lungs expanded
determines lung volume (static) not airflow
43
airway resistance
1. Inertia of respiratory system (negligible)
2. Friction
- lung tissue with itself
- lung and chest wall tissue
- resistance of air flow
44
Laminar flow
relatively little energy in airflow RESISTANCE, small airway are distal to terminal bronchioles
45
Transitional flow
extra energy needed to produce vortices, resistance increases
airflow is transitional throughout bronchial tree
46
Turbulent flow
effective resistance to airflow is highest
LARGE AIRWAYS (trachea, larynx, pharynx)
radius is large and linear air velocities may be extremely high
47
Poiseuille's law
laminar flow
R = 8nl / pi r^4
airway resistance is proportional to the viscosity of the gas and the length of the tube, but inversely proportional to fourth power of the radius
R to airflow is highly sensitive to the airway radius
48
Disease conditions of Airway resistance
typically impacted by small airways more than large ones
- smooth muscle wall contraction
- edema occurring on the walls of alveoli and bronchioles
- mucus collection in lumens of bronchioles
49
Lung compliance
| Dynamic vs static
measure of elasticity of lungs, lung expansion
CHANGE IN LUNG VOLUME produced by change in TRANSPULMONARY PRESSURE
static - measured during no gas flow
dynamic - measured during gas flow
50
Static compliance
no air flow through
51
Dynamic compliance
measured during air flow
| reflection of lung stiffness and airway resistance
52
Emphysema - high compliance
loss of alveolar tissue (less gas exchange)
| floppy lungs, less elastic recoil
53
Hysteresis
defines the difference between inflation and deflation compliance paths
Grater pressure difference is required to open a previously closed (narrowed) pathway than to keep an open airway from closing
54
Elastic components of lungs
elastin - weak spring, LOW tensile strength, extensible
| collagen - strong twine, HIGH tensile strength, inextensible
55
What determines Lung Compliance
Elastic components - elastin, collagen
| Surface Tension - air/-water interface within the alveoli
56
alveolar surface tension
water molecules at the surface of a gas-liquid interface are attracted strongly to the water molecules within the liquid mass
surface tension measures the attractive forces acting to pull a liquid's surface molecules together
57
Factors that affect pressure-volume relation
air inflation
| liquid inflation
58
Laplace's equation
describes EQb:
P=2T/r
the smaller the bubbles radius is, the grater pressure needed to stay inflated
59
Alveolar surfactant
Produced by Type II alveolar cells
Lowers surface tension ( level of alveoli)
Stable against collapse
60
Surfactant and surface tension
Phospholipids mixture
Dipalmitol-phosphatidylcholine
breaks the strong attractive forces at the surface of water
61
T/F - there is a constant amount of surfactant in every alveoli
True
| Equalizes pressures between alveoli of different sizes
62
T/F - More dense/concentrated surfactant equalizes alveloi
TRUE
no pressure gradient
small alveoli will not collapse
63
Infant Respiratory Distress
Premature infants - lack of surfactant decreases compliance, increases work required to breathe
64
Regional differences in ventilation -
Gravity and Position
| Radioactive Xenon inhaled
65
Highest amount of ventitialtion
Back of lungs
66
What explains Regional Differences in Pip
Weight of lungs increases pressure near bottom of
67
How is Inter-pleural pressure created
68
Gas Exchange
69
Partial pressure of Gases
70
Dalton's Law
In a mixture of gases - each gas operates independently
| Ptotal = P1 + P2 + P3 ...
71
Partial pressure of Gases at atmosphere at SEA LEVEL
760 mmHg = Patm
72
Diffusion: how gas crosses the Blood-gas barrier
Ficks law explains the rate of transfer of has through a sheet of tissue/unit of time
73
Respiratory Membrane
minimal thickness
74
Solubility of gases in Liquids
```
Diffusion constant (D)
CO2 solubility is much highter than O2
```
75
Henry's Law
the amount of gas dissolved in a liquid is direction proportional to the partial pressure of gas in which the liquid is in equilibrium
76
Diffusion of gases in liquids
amount of gas in the liquid is dependent on the solubility
77
PP of oxygen decreases in alveoly
| PP of CO@ increases in alveoli
78
Why does CO2 partial pressure decrease?
79
slide 128
Air is warmed up and humidified
80
Determinants of alveolar Po2:
1 Po2 in atmosphere
2 alveolar ventiliation
3 metabolic rate
4 perfusion
81
Gas exchange between alveoli and blood
Blood gasses EQb quickly
82
Perfusion of the Lung
83
Systemic circulation
High pressure system
84
Why do we need a low pressure system? What is it called
Pulmonary system
Delivery blood only to lungs and high pressure is risky
Resp membrane damage
85
Low pressure system
86
Low resistance system
87
high compliance vessels
88
Positive to alveoli collapse
redirect blood to regions where gas exchange can still occur
89
Ventilation-perfusion relationship
90
Ventilation and perfusion matching
91
Bronchoconstriction
Diameter of the airway has become smaller. reduction in ventilation
92
Oxygen transport in blood
O2 - gas molecule with LOW solubility
93
Hemoglobin
2 alpha chain
2 beta chains
4 heme groups
94
Oxygen Dissociation curve
interaction between Hb and the arterial partial pressure of oxygen
95
porphoryn ring
iron atom binds to oxygen
96
O2 + Hb HbO2
reversible process
97
O2 CAPACITY
max amount of oxygen that can combine with Hb.
Depends on how much Hb is present in blood
1 g Hb combines with 1.39 mL O2
98
Hb SATURATION
Percentage of the available Hb binding sites that have O2 attached
O2 combined with Hb / O2 capacity X 100
99
What is the Dissociation curve sensitive to?
Arterial pO2 ***
pH
Temperature
pCO2
100
What influences the sigmoidal dissociation curve?
Cooperative binding
101
Cooperative Binding
When O2 binds - confirmation change of the HEME group
| TENSE ---> RELAXED
102
significance of sigmoidal dissociation curve
1. Flat portion 60-100 mmHg
| 2. Steep portion
103
sigmoidal dissociation curve plateau
Reduced alveolar Po2
104
Tense vs Relaxed state
105
Tense vs Relaxed state steep portion
```
10-40 mmHg
40-60 mmHg
Unload large amounts of oxygen
Advantage - reduction of CO2 and PO2
UNLOAD OXYGEN TO PERIPHERAL TISSUE
```
106
anemia
reduction in amount go Hb in blood
107
Polycythemia
increase in Hb amount in blood or reduction of blood volume (increases Hb concentration)
108
Carbon monoxide poisoning (and affect on O2 dissociation curve)
HbCO
Binds to Hb tighter than O2
reduced O2 binding to Hb
LEFT SHIFT = decreased unloading of O2 to tissues; conformational change
109
saturation
Hb cannot hold more O2, sigmoidal curve flattens
110
Oxygen movement in lungs and tissues
driven by pressure gradient generated by two different environments
111
pH change on O2 dissociation curve
RIGHT shift
112
Oxygen movement at level of respiratory membrane
Po2alv >> po2blood
113
Oxygen movement in peripheral tissue
capillary
peripheral tissue cells consumed dissolved O2
intracellular space --> mitochondria
114
Temp change on O2 dissociation curve
Favour oxygen unloading
| RIGHT shift
115
PCO2 change on O2 dissociation curve
Favour oxygen unloading
| RIGHT shift
116
Right shift
lower percentage of Hb that has bound oxygen
More unloading of oxygen
higher metabolism
117
Left shift
less oxygen unloading
| cell/body metabolism
118
2,3-diphosphoglycerate (DPG)
end product of RBC metabolism
RIGHT SHIFT
increase - chronic hypoxia
high altitude, lung disease
119
Carbon dioxide transport in blood
CO2 is much more soluble in water than oxygen is
| Peripheral tissue --> respiratory system
120
```
Carbonic anhydrase (CA)
Carbonic acid - H2CO3
```
In RBC
Decrease pH
Catalyzes reaction where CO2 reacts with water
121
CO2 forms in blood (3)
Dissolved (5%)
Bicarbonate HCO3- (60-65%)
Carbamino compounds (25-30%0
122
Bicarbonate HCO3-
123
what does Carbonic acid dissociate into
H2CO3
| dissociates into bicarbonate and H+ ions
124
Chloride Shift
HCO3- (bicarbonate) leaves RBC, stays in plasma
| Cl- move into RBC, maintaining electrical neutrality in RBC
125
Carbamino Groups
CO2 interacts with amino groups in blood proteins
| Periphery --> alveolar tissue
126
Carbaminohemoglobin
Hb + CO2 HbCO2
| No enzyme required
127
T/F - DeoxyHb has higher affinity for CO2
True
128
High levels of CO2 results in large in increased oxygen unloading
129
Respiratory Acidosis
hypoventilation
CO2 is produced faster than it is eliminated
decreased PCO2, increased H+
130
Respiratory alkalosis
Hyperventilation
Co2 is removed faster that it is produced
decrease in both PCO2 and H+
131
Metabolic acidosis
Increased H+ in blood (independent from PCO2 changes)
132
Metabolic alkalosis
Decreased H+ in blood
| independent from PCO2 changes
133
Physiological pH
7.4
| venous blood is slightly more acidic(7.3)
134
What buffers the blood
Hb
135
What controls the automatic rhythm of breathing
Central nervous system
Pontine respiratory group
Dorsal respiratory group
***Ventral respiratory group
136
What does the medulla do
Initiates breatihing via specialized neurons
137
What modifies breathing
Higher CNS structures via CNS and input from central and peripheral chemo/mechano receptors
138
PreBotzinger complex
neurons in ventral respiratory group
| Excitatory INSPIRATORY RHYTHMIC ACTIVITY (polysynaptic pathway)
139
Parafacial respiratory group (pFRG)
active contraction of abdomen muscles
140
Possible changes that need to accommodate breathing
1
2
3
4
141
Rhythm of Breathing
Generated in Ventral Resp Group (VRG)
PreBotC and pFRG neurons drive activity in premotor neurons
these excite motoneurons which active rhythmically respiratory muscles
Rhythmic activity is influenced by sensory and neuromodulatory (NT) units organization from different regions within and outside CNS
142
Neuro-Repiratory Pathways - Inspiration
143
Neuro-respiratory Pathways - Active Respiration
144
Control of ventilation by PO2, PCO2, H+
```
TV and rest rate respond to these changes
Hypoxia
hypercapnia
acidosis
INCREASE ventilation, raise PO2, dec CO2
```
145
Peripheral Chemoreceptors
Carotid and Aortic bodies
Carotid - baroreceptors
sense hypoxia, sensitive to pH
146
Carotid bodies
```
small
chemsensitive
vascularized
high metabolic rate
Type 1 - Glomus cell (chemosensitive)
Type 2 - Sustentacular cells - support
```
147
Glomus cells
Neuron-like characteristics
148
What stimulates chemoreceptors
Arterial PO2 value below 60 mmHg
149
Central chemoreceptors
indirectly sense changes in PCO2
Rostral, intermediate, caudal regions of medulla
medullary raphe, hypothalamus
excitatory drive
150
hypercapnia
too much CO2 in blood
| response is mediated dorsal and ventral group (change ventilation)
151
Lactic acid
reduce blood pH, increase H+ concentration
during exercise
hyperventilation
