Pulmonary Ventilation and Circulation Flashcards
1
Q
pleurae
- what are they
- potential pathology
- involves which step of the O2 transport system
- what would you hear with auscultation
A
outside coverings of lungs potential pathology -pleurisy/pleuritis O2 system -step 3? friction rub sound with auscultation
2
Q
what are aventitious breaths?
-types
A
abnormal sounds that are heard over a patient’s lungs and airways
- crackles (rales)
- wheezes
- pleural rubs and stridor
3
Q
lung tissue
- made of
- benefit of this composition
A
primarily elastic connective tissue
elasticity of healthy lungs helps reduce the work of breathing
4
Q
bronchopulmonary segments
- _____ vs. _____
- separated by…
- served by own _____
- receives air from an individual _____
A
R vs. L separated by connective tissue septa served by own artery and vein receives air from an individual bronchus clinical relevance
5
Q
R bronchopulmonary segments
A
upper -apical -anterior -posterior middle -lateral -medial lower (base) -anterior -superior -lateral -posterior -medial
6
Q
L bronchopulmonary segments
A
upper -apical posterior -anterior -superior (lingula) -inferior (lingula) lower (base) -anterior -superior -lateral -posterior
7
Q
upper respiratory tract
- location
- components
A
from nasal and oral orifices to the false vocal cords in the larynx
- nose
- nasal cavity
- pharynx (naso-, oro-, laryngo-)
- larynx
8
Q
lower respiratory tract
- location
- components
A
from level of true vocal cords to the alveoli components -trachea -R and L primary bronchi -second, tertiary, etc. bronchi -bronchioles -terminal bronchioles -respiratory bronchioles -alveolar duct --> alveolar sacs --> alveoli
9
Q
lower respiratory tract
-divided into what 2 regions
A
conducting and respiratory zones
10
Q
conducting zone
-location
A
trachea through terminal bronchioles
11
Q
conducting zone
- trachea bifurcates at about…
- bifurcates into…
- these divide into…
A
trachea bifurcates at about T7
bifurcates into R and L main bronchi
main bronchi divide into lobar bronchi
12
Q
conducting zone: lobar bronchi
- how many
- divides into…
A
3 on R, 2 on L
divides into segmental bronchi (tertiary)
13
Q
conducting zone
-about how many order of branching air passageways
A
about 23
14
Q
conducting zone: bronchioles
-size
A
< 1 mm diameter
15
Q
conducting zone: terminal bronchioles
-size
A
< 0.5 mm in diameter
16
Q
where and what is the anatomic dead space?
A
conducting zone + upper airway
space in respiratory passage where gas exchange does not occur
about 150 ml’s
17
Q
transition into respiratory zone
-begins…
A
begins where terminal bronchioles feed into respiratory bronchioles
18
Q
respiratory zone
- contains ____ air at rest
- holds up to _____ with max inspiration
A
2.5 L air at rest
up to 4-6 L with max inspiration
19
Q
alveoli
- walls composed of…
- external surface covered by…
A
walls composed of a single layer of Type I cells - squamous epithelial - surrounded by basement membrane
external surface covered by a “web” of capillaries
20
Q
respiratory membrane
-composed of
A
composed of
- alveolar epithelial cells
- capillary walls
- fused basement membrane
21
Q
how much O2 and CO2 leaves and enters the alveoli per minute, respectively
A
250 ml O2 leaves alveoli to blood
200 ml CO2 diffuse from blood to gas in alveoli per minute
22
Q
alveoli type II cells
-function
A
secrete surfactant
23
Q
what is a pathology that can affect the efficiency of the alveoli
A
pulmonary edema
24
Q
anatomical dead space
-definition
A
volume of all the space of the respiratory system other than alveoli and their closely related gas exchange areas
25
physiological dead space
| -what is it
alveolar dead space ( usually due to diseased state) + anatomical dead space
26
how different should normal and pathological dead space be from each other in a healthy individual
should be similar
27
blood supply to lung tissue
- comes from
- this blood is drained through...
comes from bronchial arteries
-off of thoracic aorta
drains into pulmonary veins
-this will decrease the partial pressure of O2 in the pulmonary veins, since it is deoxygenated
28
PSNS effect on airways
constricts air tubes
- ACh released - smooth muscle contraction
- increases airway resistance
- slows and reduces volume of airflow
29
SNS effect on airways
dilates air tubes
- weak direct control by sympathetic nerve fibers
- EPI and NE - smooth muscle relaxation
- -stronger affect by epi and ne released in blood: released by adrenal medulla following SNS stimulation
- reduces airway resistance, enhances flow
30
five major functional events of respiraton
```
pulmonary ventilation
external respiration
transport of respiratory gases
internal respiration
regulation of respiration/ventilation
```
31
five major functional events of respiraton
```
pulmonary ventilation
external respiration
transport of respiratory gases
internal respiration (at the muscle)
regulation of respiration/ventilation
```
32
pulmonary ventilation
| -what is it
movement of air into and out of lungs
33
pulmonary ventilation
| -mechanisms of expansion/contraction of lungs
contraction of diaphragm: lengthens or shortens the chest cavity
elevation/depression of ribs
34
diaphragm function
primarily responsible for quiet inspiration
contracts: dome shape "flattens"
increases thoracic volume
relaxes back to dome shape during quiet expiration
decreases thoracic volume
35
additional inspiration muscles
```
elevation of ribs
-external intercostals
other muscles
-SCM
-scalenes
-serratus anterior
-pectoralis minor
-erector spinae muscles
```
36
expiration muscles
recruited with increased respiratory demands/forced expiration
- internal intercostals
- rectus abdominis
37
respiratory pressures are always described relative to...
atmospheric pressure (760 mmHg)
38
intrapulmonary pressure
- where is this pressure
- wants to...
alveolar pressure
| wants to equalize with atmospheric pressure
39
intrapleural pressure
- where is this pressure
- what is the pressure?
pressure in pleural cavity
| about -4 mmHg (lower than atmospheric pressure by 4 mmHg)
40
Boyle's Law
| -what does it say
at constant temperature, the pressure of a gas varies inversely with its volume
41
alveolar pressure
- what is it?
- during inspiration...
- during expiration...
pressure inside lung alveoli
during inspiration
-alveolar pressure drops slightly to -1 cm H2O
-enough change to allow 500 mL air to be pulled into lungs in about 2 seconds
expiration
-alveolar pressure rises to 1 cmH2O
-drives air out of alveoli in 2-3 seconds
42
transpulmonary pressure
- what is it
- function
alveolar pressure minus intrapleural pressure
function
-keeps air spaces of lungs open
-difference between the alveolar pressure and the pleural pressure
43
atelectasis
| -what is it?
lung collapse (or part of lung collapses)
44
pneumothorax
| -what is it
presence of air in intrapleural space
45
alveolar ventilation per minute
- what is it
- major factor in...
total volume of new air enterior the alveoli and their adjacent gas exchange areas each minute
major factor in determining the concentration of O2 and CO2 in the alveoli
46
resistance to airflow in bronchial tree during
- normal respiratory conditions
- diesease conditions
normal
-larger bronchioles and bronchi near trachea provide greatest amount of resistance to airflow
disease
-smaller bronchioles provide greater resistance to airflow
47
lung compliance
- what is it?
- a normal lung is _____
- determined by...
measure of the change in lung volume that occurs with a given change in transpulmonary pressure
a normal lung is distensible
determines by
-distensibility (elastic forces) of lung tissue
-alveolar surface tension
--surfactant
48
idiopathic pulmonary fibrosis is an example of a _____ lung disease
restrictive
49
surfactant
| -surface tension principle
"raindrop"
alveoli without surfactant
the smaller the alveolus, the greater the alveolar pressure causes by the surface tension
50
surfactant
- composition
- functions
phospholipids, proteins, and ions
functions
-greatly reduces surface tension
-reduces effort required by respiratory muscle to expand the lungs
51
why is the intrapleural pressure negative
2 forces act to pull lungs from the thorax wall (parietal pleura) which would cause lung collapse
-lungs natural tendency to recoil
-surface tension of alveolar fluid
opposed by natural elasticity of chest wall
maintaining pleural fluid adhesive force
combination of all forces
52
when is surfactant first secreted into the alveoli
7 months gestation
53
what would happen if a baby is born prematurely without surfactant being produced?
lungs would want to collapse
54
work of breathing
- 3 components during quiet breathing
- energy expenditure
```
components
-compliance work or elastic work
-tissue resistance work
-airway resistance work
energy expenditure
-3-5% total body energy expenditure required for pulmonary ventilation
```
55
relationship of flow, velocity, cross-sectional area
flow = change in pressure / resistance
| flow will decrease with increased resistance
56
pulmonary function measurements
```
inhaled minute volume (Vi)
exhaled minute volume (Ve)
FVC
FEV1
Minute respiratory volume
```
57
Vi
| -what is it
volume of gas inhaled per minute
58
Ve
| -what is it
volume of gas exhaled per minute
59
FVC
total volume of air that can be exhaled during a forced exhalation
60
FEV1
| -what is it
amount of vital capacity that can be exhaled in 1 second
61
minute respiratory volume
| -equation
RR x tidal volume
62
pulmonary circulation - heart to lungs
pulmonary artery --> R and L main branches --> continual branching
-thin walled
-short
-larger diameters than systemic counterparts
-much more compliant: can accommodate stroke volume output of R ventricle
pulmonary vein
63
blood volume and distribution
- blood gets distributed to alveoli with...
- low O2 in alveoli causes...
- -this reaction is opposite to...
blood gets distributed to alveoli with best oxygenation
| low O2 pressure in alveoli causes capillary constriction - opposite to systemic capillary reaction to low O2 pressure
64
if alveolar pressure is greater than capillary? pressure..
capillaries close and no blood flow
