Resp 1 Flashcards
1
Q
Visceral Pleura:
A
Attaches to
the surface of the lung
2
Q
Parietal Pleura:
A
Covers the
surface of the chest wall,
diaphragm, and mediastinum
3
Q
Pleural Space:
A
Contains a very thin layer of pleural fluid under negative pressure.The pressure in this space is referred to as the Intrapleural Pressure (PIP)
4
Q
PIP is subatmospheric
pressure, which ensures that
A
the lungs are held to the
chest wall and will move with
the chest wall during
inspiration & expiration.
5
Q
A pleural effusion is
A
excess fluid in the pleural space, which makes lung
Expansion difficult so the person will
breathe shallow and fast.
6
Q
The right lung has — lobes and the
left has —.
A
three
two
7
Q
Each lung has zones that differ in the (2)
A
amount of air (ventilation; V) and blood
(perfusion; Q) that they receive.
8
Q
There is greater ventilation (V) of alveoli and blood flow (Q) into
capillaries in zone – compared to the other zones.
A
3
9
Q
Best region for
gas exchange. Normally, most of the lungs are zones (2)
A
3 and 2
10
Q
The respiratory system is divided into two functional
zones:
A
Conducting Zone and Respiratory Zone
11
Q
The diameter of the tubes --- as you move down, but the number of each ---
A
decreases
increases
12
Q
There is a large increase in --- as you move deeper into the conducting zone and exchange surfaces.
A
surface area
13
Q
Airways have a --- in cartilage and an --- in smooth muscle as you move along the airways.
A
decrease
increase
14
Q
In the Conducting Zone, air is (3)
A
warmed, humidified and filtered
15
Q
function of cartilage and smooth muscle
A
Cartilage prevents its collapse
smooth muscle alters resistance to
airflow (Beta 2 receptors, Muscarinic
receptors, Allergen Activation –
Asthma).
16
Q
The Respiratory Zone has a
A
Greater
Surface Area to Optimize the Surface
Area Available for Gas Exchange
17
Q
velocity equation
A
flow/cross-sectional area
18
Q
Total cross-sectional area greatly increases in
the — zone, so velocity of air flow this
zone is —
A
respiratory
low
19
Q
Cells Types in Alveoli (3)
A
1. Type I Cells (Simple Squamous Epithelial Cells) 2. Type II Alveolar (Produce Surfactant) 3. Macrophages
20
Q
The basement membrane of the endothelium
and of the alveolar epithelium are
A
fused
21
Q
The typical transit time at rest for an erythrocyte through an alveolar capillary is
A
0.75 seconds.
22
Q
Gas exchange is
usually complete in
A
0.25 seconds
23
Q
Gas exchange is usually complete in 0.25 seconds, so even during exercise when the capillary transit time is faster, there is still time for
A
gas exchange to reach diffusion equilibrium (PAO2 & PaO2 = 100 and PACO2 & PaCO2 = 40).
24
Q
Respiratory muscles are —
muscles
A
skeletal
25
Neurons in the medulla and pons
| control their
alpha motor neurons.
26
nspiratory Muscles: (2)
– Diaphragm, external intercostals
– Contraction INCREASES the size of
the thorax and lungs (causing decrease PALV)
27
Expiratory Muscles: used for
forced expiration only
28
Expiratory Muscles: (2)
– Internal Intercostals, abdominal
muscles
– Contraction DECREASES the size
of the thorax and lungs (causing increased PALV)
29
The --- is the primary inspiratory
| muscle.
diaphragm
30
The diaphragm is the primary inspiratory
muscle. It arches over the liver and moves
down like a piston when it contracts,
which (2)
increases the size of the thoracic
cavity and reduces the pressure in the
thorax/lungs.
31
Expiratory muscles
ONLY contract with
--- expiration
ACTIVE
32
The --- push
abdominal contents up against
the diaphragm (compressing
the lungs) and the --- depress the ribs.
abdominal muscles
internal intercostals
33
Air is a mixture of ---
gases
34
Gases have different ---
pressures
35
Air moves from
high pressure to low pressure
36
Boyle’s Law
```
P1V1 = P2V2
In a sealed
container,
pressure times
volume equals a
constant.
If pressure
increases, volume
decreases and
vice versa.
```
37
For air to
ENTER the
lungs,
```
the
pressure in the
alveoli (PALV)
must be lower
than
atmospheric
pressure (PATM)
```
38
For air to LEAVE
| the lungs,
```
the
pressure in the
alveoli (PALV)
must be higher
than atmospheric
pressure (PATM)
```
39
The chest wall and the lung
| both wish to recoil apart (2)
– Chest outward recoil
– Lung inward recoil (due to
alveoli)
40
The elastic recoil of the lungs favors a
decrease in lung volume or compression
41
the elastic recoil of the chest wall favors an
increase in lung volume or expansion.
42
The intrapleural fluid
overcomes that
recoil, keeping
```
the
two attached
together, so when
the chest (thorax)
moves, the lungs
move with it.
```
43
Transmural or Transpulmonary Pressure
PTP = Palv – Pip
Must increase to produce I and decrease to produce E.
If PIP = PATM, then PTP is 0 and
there is no longer a force to keep
the lungs open (Pneumothorax).
44
Nearly half of the energy expended for I is stored in --- and during E this stored potential
energy is
elastic recoil
released and overcomes airway resistance.
45
inspiration begin at rest when
Patm = Palv
46
Inspiration:
Inspiratory Muscles contract and the VOLUME of
the thorax (and lungs) ---.
increases
The decrease in PIP (from -5 to -7.5 mmHg) causes PTP to increase ( to 7.5
mmHg) and this causes lung volume to increase.
47
Inspiration:
Because volume has increased, the pressure in the
lungs (Palv)
decreases (to -1 mmHg).
48
Inspiration:
| When Palv < Patm, air flows -- the lungs
into
49
Inspiration:
| When Palv < Patm, air flows into the lungs (3)
a. As air enters the lungs, Palv begins to increase again.
b. Air flow continues until Palv = Patm.
c. No difference in pressure, no difference in flow.
50
Inspiration:
| These pressure changes lead to movement of
```
500 mL (Tidal Volume) of air.
Moving a larger volume of air would require more muscle contraction leading to
greater volume and pressure changes.
```
51
Expiration
| Begin after
inspiration when Patm = Palv
52
Expiration:
| in relaxed breathing, it is a passive process due to
relaxation of inspiratory muscles
a. Can increase the rate and volume of expiration by
contracting expiratory muscles (active expiration).
53
```
Expiration:
The thorax (and thus the lungs) --- in volume.
```
decrease
Lung volume decreases because the decrease in thorax volume causes an increase in PIP (from -7.5 mmHg to -5 mmHg) which causes PTP to decrease (from 7.5 mmHg to 5 mmHg).
54
Expiration:
| Because volume decreases, lung pressure (Palv)
increases (to +1 mmHg)
55
Expiration:
| As soon as Palv > Patm,
air flows down pressure
| gradient and out of the lungs
56
Expiration:
As soon as Palv > Patm, air flows down pressure
gradient and out of the lungs (2)
a. As air leaves the lungs, Palv decreases.
| b. When Palv = Patm, air flow stops
57
LUNG COMPLIANCE
| a. Definition:
ability of the lung to stretch
58
compliance= equation
deltaV/deltaP
59
i. High compliance:
| ii. Low compliance:
Lung stretches easily
Difficult for lung to stretch
60
Alveoli in the base of the lungs are more (2)
compliant and
| undergo greater expansion during inspiration
61
Opposite of compliance is elasticity—
lung’s ability to return to its
| normal, resting position.
62
High compliance =
Easy
| Stretch
63
High elasticity =
Easy Recoil
64
Lungs with lower compliance (ex. Pulmonary Fibrosis)
| require
a larger transpulmonary pressure (PTP) to increase volume
65
Obstructive Lung Disease (ex.
| Emphysema)
Elastic fibers destroyed
increase compliance: Will breathe
deep and slowly to reduce the
work of breathing.
66
Restrictive Lung Disease (ex.
| Pulmomary Fibrosis)
decrease compliance: Will breathe
shallow and fast to reduce the
work of breathing.
67
Surface Tension:
Force that occurs at any gas-liquid
| interface due to the cohesive forces between liquid molecules.
68
Liquid has a strong attraction for itself and alveoli are covered with a
thin layer of fluid.
69
This means that the fluid covering of alveoli exerts a
constant
| force favoring contraction (which means collapse of alveoli).
70
The Law of LaPlace describes the relationship between
surface tension and radius of an alveolus.
71
If two alveoli are connected and the
surface tension of each is equal, the
pressure in the small alveolus is
---.
greater
72
```
If two alveoli are connected and the
surface tension of each is equal, the
pressure in the small alveolus is
greater.
Because of this, air will flow
```
into the alveolus.
73
Surfactant fxn (2)
reduces surface
tension and equalizes pressure
between alveoli of different sizes.
74
P=
2T/r
```
P = Collapsing Pressure
T = Surface Tension
r = Radius
```
75
Pulmonary surfactant is secreted by
Type II alveolar
| cells.
76
Pulmonary surfactant is secreted by Type II alveolar cells. It --- surface tension (thus elasticity) and --- compliance.
decreases
| increases
77
Surfactant is primarily made up of
phospholipids. It
spreads over the fluid lining of the alveolar surface to
disrupt surface tension forces.
78
Some components of surfactant are components of
innate immunity
79
Surfactant is particularly important for
reducing surface
| tension in small alveoli.
80
Surfactant is particularly important for reducing surface
tension in small alveoli.
i. This --- the likelihood of alveolar collapse.
decreases
81
Surfactant decreases the work of ---.
inspiration
82
Surfactant production is increased with (3)
hyperinflation of the lungs (sighing and
| yawning), exercise and Beta-adrenergic agonists.
83
Multiple pathologies are associated with decreases in surfactant production – (3)
Infant Respiratory Distress Syndrome, Acute Respiratory Distress Syndrome,
Chronic Smoking
84
Air Flow =
(Patm – Palv)/Resistance (R)
R = 8nl/pir^4
```
R = Resistance
n = Viscosity of air
l = length of airway
r = radius of airway
```
85
Determinants of Resistance: (3)
i. radius of bronchi/bronchioles
ii. Viscosity of substance
iii. Length of tube
86
radius of bronchi/bronchioles (3)
a. Bronchodilation: EPI on β2, decrease O2, increase CO2
b. Bronchoconstriction: ACH on M, increase O2, decrease CO2, Histamine
c. Mucus accumulation
87
The airways with the smallest radius (r)
have the highest individual resistance
(R), but the total resistance (R) of that
generation is the smallest. Why?
88
Pathologies that increase airway resistance -
OBSTRUCTIVE
| DISEASES (ex. Asthma, Emphysema, Bronchitis)
89
Inspiratory Reserve
| Volume.
3000 ml
90
Tidal Volume.
500 ml
91
Expiratory Reserve
| Volume.
1100 ml
92
Residual Volume.
1200
| ml
93
Anatomic Dead Space
94
~ 1ml of Anatomic dead
space per pound of ideal
body weight, which is the
conducting zone of the
| respiratory system.
95
Physiologic Dead Space
96
Physiologic Dead Space =
Anatomic DS + Alveolar DS
97
alveolar DS in a healthy young person vs low cardiac output
A healthy young person has little or no alveolar dead
space. However, someone with low cardiac output
might have a lot of alveolar dead space due to low
perfusion and thus a higher V/Q ratio.
98
Vital Capacity.
a. VC = IRV + ERV + TV
99
Total Lung Capacity.
a. TLC = VC + RV
100
Inspiratory Capacity
a. IC = TV + IRV
101
Functional Residual Capacity
a. FRC = ERV + RV
102
A normal respiratory rate is between --- breaths/minute at rest.
12-20
103
Minute, Pulmonary or Total Ventilation =
Tidal volume (ml/breath) X Respiration Rate (breaths/minute)
104
Alveolar Ventilation =
(Tidal volume – Dead Space Volume) X Respiration Rate
105
It is better to breathe deeper
| instead of faster as
deeper
breaths get more air into the
respiratory zone for gas
exchange!
106
The amount of
air in the
conducting
zone is
~150
mL (ANATOMIC
DEAD SPACE).
