Respiratory Physiology Flashcards
0
Q
TRUE or FALSE
O2 transport and CO2 removal from the fetus occur by ACTIVE diffusion across the maternal circulation
A
False
PASSIVE
1
Q
What is the goal of breathing?
A
(Mechanical perspective) Minimize work
(Physiological) Maintain blood gases
Regulate arterial PCO2
Maintain acid-base balance in the brain
2
Q
How come:
High CO2 = Low pH (acidic)
Low CO2 = High pH (alkaline)
A
Low pH (acidic) = Higher concentration of HCO3 + H+ in the blood (bicarbonate and hydrogen ions)
Review how CO2 is transported from the tissues:
Dissolved in plasma - 10%
Carboamino Hb (CO2 in Hb) - 20%
Bicarbonate plasma - 70%
3
Q
What are the functions of the Respiratory System?
A
Gas Exchange (O2 and CO2) Heat Exchange Blood Gas Homeostasis Phonation Defense Bioactive Substrate Metabolism
4
Q
Boyle’s Law
A
Pressure Increases = Volume Decreases
LUNGS INFLATE
Inspiration
Pressure Decreases = Volume Increases
LUNGS DEFLATE
Expiration
5
Q
When the chest expands (air goes in), what happens to the pressure?
A
Pressure decreases
NEGATIVE PLEURAL/ALVEOLAR PRESSURE
6
Q
When air enters the cavity, the lung may collapse. The mediastinum may compress the other lung. What condition is this?
A
Tension Pneumothorax
7
Q
In pneumothorax, intrapleural pressure becomes _____?
A
Zero
No expansion happens
The lung collapses
Compromises both lungs
8
Q
We work to _____
We relax to _____
A
Inhale
Exhale
9
Q
Smoking compromises the elastic recoil ability of the lungs. That leads to what condition?
A
Emphysema
10
Q
Instrument that measures lung volume (except for residual volume)
Measures vital capacity
A
Spirometer
11
Q
TRUE or FALSE
If you exhale hard enough, you can empty your lungs
A
FALSE
Some air remains inside = Residual Volume
12
Q
The lungs can carry how many liters of air?
A
7
13
Q
How can you tell if the baby died before or after birth?
A
Put the lungs in a basin of water
If it floats, then air has not yet entered the lungs
DEAD BEFORE BIRTH
If it sinks, then air has entered the lungs
DEAD AFTER BIRTH
14
Q
Volume of air that can be maximally exhaled from the lungs
Measured by spirometry
A
Vital capacity
15
Q
Human airways is likened to an _______?
A
Inverted Funnel Model
16
Q
Molecules move according to their concentration gradient.
Which will move lower, CO2 or O2?
Which will move up?
A
O2, because it is needed by the body
There is less O2 in the lungs
CO2 will move up because it is being exhaled
There is high concentration of CO2 in the lungs
17
Q
How do O2 reaches the alveoli?
A
Simpe diffusion
Higher concentration to lower concentration
18
Q
Which has no alveoli, terminal or respiratory bronchiole?
A
Terminal
19
Q
Conducting portion
No alveoli
A
Deadspace
20
Q
V(alveolar) + V(deadspace)
A
V(tidal)
21
Q
How many mm between respiratory zone and conducting zone?
A
1 mm
22
Q
Walls of the alveoli are not smooth; there are undulations
These undulations are ________
A
Capillaries with RBC
Rolls of capillaries
23
Q
The type of epithelium is found in the alveolus and makes gas exchange possible
A
Cuboidal epithelium
Gas exchange is between one alveolus and another alveolus
24
Flat cells found in the epithelium of the lungs
Type I pneumocyte
vs Type II pneumocyte
25
TRUE or FALSE
Lung changes in volume with each breath by roughly 15% only, allowing gas exchange to continue during expiration
True
26
TRUE or FALSE
The airway is stimulated by the parasympathetic fiber
True
27
Resistance is high in the trachea and main bronchi
Therefore, the flow of air here is
A. Turbulent
B. Laminar
C. Depends on the depth of inhalation and exhalation
A
Flow/velocity of air is faster in a narrow area (high resistance)
Resistance obeys the Ohm's Law
E = IR
28
The flow of air in the bronchioles is termed ______.
Hint: Opposite of turbulent
Laminar flow
29
Relationship of airway resistance and lung volume
Resistance increases as lung volume decreases
30
What keeps the bronchioles open?
Attachment of alveoli
31
During forced expiration (cough)
Tubes become smaller
Secretions are removed
Dynamic airway compression
32
This theory states that the pressure is the same throughout the thoracic cavity
Equal Pressure Point Theory
33
Primary determinant of maximum flow rate
Lung elastic recoil (P)
Alveolar pressure increases
34
What is the best way to cough?
1. Take a deep breath
2. Lung elastic recoil
Airway collapses during forced expiration
35
TRUE or FALSE
Airway resistance...
1. Increases even if there is no air flow across the airway
2. Highest at the level of the smaller airways
3. Lowest at the trachea
All FALSE
Resistance is high at the level of larger (central) airways
36
When we cough, the intrapleural pressure becomes?
Positive
The bronchi will collapse in expiration because of positive infrathoracic pressure
37
If the obstruction is in the airway, sound is _________ as in the case of ________
Inspiratory (breathe in), tumors (?)
vs obstruction in the bronchioles, as in the case of asthma (sound is expiratory) ---> wheezing when expiring
38
Normal lung compliance
0.2 L / cmH20
39
What is the role of elastic fibers in lung compliance?
Arrangement of fibers affects elastic recoil
40
Why is it harder to expand a lung distended in air than in saline?
Surface tension
Polarity and Surface Tension:
Water-Water Walang masyadong tension
Air-Water Tension exists to support objects (happens in all alveoli)
41
Relationship of variables?
Law of Laplace:
Pressure
Tension
Size of alveolus
Law of Laplace:
High pressure
High tension
Small size of alveolus (radius)
Pressure is inversely proportional to radius
P = 2T/r
If tension is high, di maeexpand ang lungs
42
Why do alveoli do not collapse due to pressure?
Surfactant (dipalmitoyl phosphotidyl choline)
- reduces surface tension
- pressure is equalized in small and large alveoli
If none: lung stiffness
Babies born preterm: no surfactant
43
Syndrome of babies born preterm, with no pneumocyte II?
Consequence?
NRDS
Neonatal Respiratory Distress Syndrome
No surfactant
44
Iron Lung
Machine that facilitates breathing when the lungs fail
45
What happens to the pressure when venous return to the heart is impeded? Positive or negative?
Very positive intrathoracic pressure
46
Gas exchange is defined as the exchange of gases between the environment and capillary blood
Respiratory quotient:
CO2
O2
RQ = CO2 production / O2 consumption
RQ = VCO2 / VO2
200 ml / 250 ml
= 0.8
47
Relationship of variables:
PO2
FiO2
Patm
PO2 = FiO2 x Patm
| 21% x 76 mmHg
48
```
Terms:
PatmO2
PAO2
PcapO2
PaO2
PvO2
```
```
PatmO2 - atmospheric pressure
PaO2 - alveolar pressure
PcapO2 - capillary pressure
PaO2 - arterial pressure
PvO2 - venous pressure
```
49
Minute Ventilation
```
Relationship of variables?
Vtidal
Respiratory Rate
Valveolar
Vdeadspace
```
```
Vmin = Vtidal x RR
Vmin = Valveolar + Vdeadspace
```
50
Relationship of variables:
```
PaO2
FiO2
Patm
PH2O
PaCO2
RiQi
```
PaO2 = FiO2 (Patm-PH2O) - [PaCO2 / RiQi]
High fresh air = High opportunity to expel CO2
Carbon Dioxide Excretion Formula
51
Determines the level of PaCO2
Alveolar ventilation
52
Regional Distribution of Ventilation
Pleural pressure is less negative sa lower lung
53
TRUE or FALSE
Upper and lower lung alveoli size are equal in size
False
Alveoli in the upper lung are bigger in size ---> suctioned by negative pressure
54
Distribution of air in the lungs
Mas malaki ang distribution ng air sa base (lower lobe), so mabilis maapektuhan ng mga sakit (Tuberculosis)
55
Fick's Law for Diffusion of Gases
Variables?
Depends on the:
Barrier
Density of Gas
Pressure Gradient
56
Perfusion Rate (Q)
Distribution of Lung Perfusion?
High in lower lobe (?)
High ventilation (at first)
High perfusion
Alveoli at apex are underperfused (overventilated)
Alveoli at the base are underventilated (overperfused)
O2 ventilation is high at base but perfusion will carry it to the rest of the body
57
Causes of Hypoxemia:
```
Low PiO2 - low O2 in the blood
Hypoventilation
Shunt
V/Q mismatch
Diffusion block
Low PvO2
```
vs
Hypoxia - loss of O2 at the level of the bronchi
Hypercapnia - high CO2
Hypoxia and hypercapnia usually go together
58
Henry's Law of Gases
O2 dissolved in 100ml plasma = PO2 (mmHg) x 0.003 ml/100 ml blood
= 0.3 ml O2
59
Hemoglobin can carry?
1.34 x Hb (grams) x %Sat
= 19.7 ml O2/100 ml blood
O2 saturation of 98 - 100 is NORMAL
60
TRUE or FALSE
Hemoglobin will load O2 if the concentration in the surrounding area is high
TRUE
Affinity is high when the O2 concentration is high
Load only if: PO2 in the surrounding area is high
61
TRUE or FALSE
Hemoglobin will unload O2 in the surrounding area if the surrounding area is high in O2
FALSE
Tendency to unload is low when concentration is high
Unload only if: PO2 in the surrounding area is low
62
How to resuscitate a patient?
Give blood, hemoglobin
Why not O2?
Too much would burn the lungs. We are accustomed to 21% (kapag naka-mask)
Danger: 100% O2 --- Toxicity
There is a saturation point, 100% O2 will not guarantee 100% saturation
63
The graph shifts to the right when the affinity of Hb to O2 is increased or decreased?
Increased
There would be loading of O2 because of high concentration/saturation of O2 in the surroundings
TRANSPORTER > PROVIDER
Occurs in the lungs
vs shift to the LEFT, O2 will be released because concentration/saturation in the surroundings is low
TRANSPORTER < PROVIDER
Occurs in peripheral tissues
64
What will happen to the pH, DPG and temperature of the exercising muscle?
High pH, Low DPG, Low Temp
Shift to the LEFT
O2 is supplied to the muscle because it is needed
Hb would release O2
65
Bohr Effect
...
66
Binding of O2 to hemoglobin promotes release of CO2. The effect is called?
Haldane effect
67
Identify the types of hypoxia:
1. O2 in the external environment is low in O2 (e.g. Mt. Everest)
2. O2 can't be transported because Hb is inadequate
3. O2 concentration is good, but blood pressure is low
4. Effect of cyanide, cytochrome problem in the mitochondria (during ETC)
1. Hypoxic
2. Anemic
3. Stagnant
4. Histotoxic
68
Determined by the amount of H+ ions
pH - acidity and alkalinity
69
How many grams of H+ ions per liter are there in
pH 0
pH 1
pH 0 1.0 g/L
pH 1 0.1 g/L
pH 2 0.01 g/L
70
pH below 7.35
pH above 7.45
Acidemia - consequence of acidosis
Alkalemia - concequence of alkalosis
71
Acid-Base Balance
Henderson Hasselbach Equation
72
TRUE or FALSE
Our body produces more acids than bases
True
Acids are from:
Intake of foods
Produced by lipids and proteins metab
Cellular metabolism of CO2
73
Compensatory mechanisms to regulate body mechanisms
Respiratory compensation
| Kidney compensation
74
TRUE or FALSE
Respiratory acidosis : Hyperventilate
Short, fast breaths to eliminate CO2
Respiratory alkalosis : Hypoventilate
Slow, deep breaths to conserve CO2
True
True
75
Increased concentration of HCO3 (bicarbonate)
Decreased concentration of HCO3 (bicarbonate)
Metabolic alkalosis : Hypoventilation
Metabolic acidosis : Hyperventilation
CO2 + H2O H2CO3 H+ + HCO3
76
Inspiratory ramp signal
Elastic recoil
77
Volitional breathing is controlled by
Cerebral cortex
78
Seat of breathing
Medulla
79
Chemoreceptor which send signals regarding altitude and levels of acidity
Peripheral chemoreceptors
80
What chemoreceptor works?
Suicide
Emphysema
Chronically hypercapnia
Central
Study aid: Know what chemoreceptors respond and what kind of response
81
TRUE or FALSE
The brain can adjust to hypoxia
False
82
TRUE or FALSE
Changes in the Pulmonary Circulation
Hypoxic pulmonary vasoconstriction
Capillary constriction
Less capillaries develop (Anti-angiogenesis)
Decreased tissue capillary density
Marked increase in left ventricle
Reduction of intercapillary distance in some peripheral tissues
```
True
True
False Angiogenesis
False Increased
False Right ventricle
True
```
83
Felt when in high altitude:
```
Decreases judgment
Drowsiness
Mental and muscle fatigue
Headache
Nausea
```
What condition?
Hypoxia
84
TRUE or FALSE
When diving, the highest change in pressure is just below the surface
True
85
TRUE or FALSE
To avoid having decompression sickness, when diving, descend slowly and ascend rapidly
False
```
Ascend slowly (nitrogen bubbles)
May descend rapidly
```
86
During exercise, how do we manage to be oxygenated?
Increase the respiratory rate
| Increase cardiac output
87
What happens to these factors when ventilation sharply increased?
Metabolism
Temperature
Hyperventilation
Increase!
88
First line of defense of the lungs
- Moist, with cilia
- Filters
Aerodynamic Filtration
89
Lung Defense
| -Characterized by squamous epithelium
Mucociliary Apparatus
90
Lung Defense
- No cilia
- Engulfs foreign particles
Alveoli Macrophage
91
During inhalation, do all gases go inside (N2, CO2, O2)?
Yes but up to a certain level
| Proportion is different
92
Most sensitive chemoreceptor
Peripheral
93
Ultimate stimulator of inspiration
Production of lactic acid
94
TRUE or FALSE
It is safe to breathe in 100% O2 for 12 hours
False
Biochemical injury
(Except for sick patients who will die of hypoxemia without enough O2)
95
High CO2
Headaches
Hypoxia
Hypercapnia
96
2 kinds of COPD
Pink puffing
| Blue bloater
97
Stabilizes deoxyhemoglobin to release O2
| Affinity decreases
2,3 DPG
98
What is it in inspiration that needed work?
Expansion of lungs
Getting air inside
(Muscular work)
99
To minimize the work of breathing, what to do with the factors involved?
Balance RESISTANCE and COMPLIANCE
100
How to breathe when you have narrow airways?
Take SLOW, DEEP BREATHS
101
How to breathe when you have stiff lungs?
Take FAST, SHORT/NARROW BREATHS
102
Stretch receptors
Where signalling comes from
103
Why suicide attempt by holding breathe would not be successful
Increase in CO2 would stimulate central receptors
| Metabolism does not stop when holding breathe, O2 is continually used up
104
When holding breathe, O2 stimulate what
Carotid receptors
105
TRUE or FALSE
Hyperventilating before diving would not pose any serious consequeces
It is highly encouraged
False
Frequent cause of deaths
There should be balance
106
Is this possible?
pH is normal
Respiratory alkalosis
Metabolic acidosis
Yes?
Low CO2, Low HCO3
107
Differential diagnosis?
pH 7.2
CO2 50
HCO3 18
Acidemia
Respiratory acidosis
Metabolic acidosis
= SEVERE ACIDEMIA
108
Condition wherein people afflicted suffer from respiratory arrest during sleep
Failure of the autonomic control of breathing
Derived from Greek mythology
Ondine's curse
Congenital central hypoventilation syndrome (CCHS) / Primary alveolar hypoventilation
109
What is the effect of hypobaric pressure?
You are a pilot in an airplane when the windows gave way. What will you do?
Decompression
Fly the airplane in a lower altitude
