Pulmonary - Exam 2 Flashcards
adequate gas exchange needs adequate (4 things)
- ventilation
- perfusion
- distribution of ventilation
- ability for diffusion of CO2 and O2 across alveolar-capillary membrane
normal lung function depends on the maintenance of these 3 things
- PO2
- PCO2
- arterial pH
WITHOUT EXCESSIVE CARDIAC OR PULMONARY WORK
lung structure is comprised of
airway and alveoli
airways are categorized into
23 generations
conducting airways are numbers __-___ and have no
0-16, have no gas exchange
conducting airways are made up of (3)
- trachea - 0
- segmental bronchi - 1-3
- bronchioles (non-respiratory) - 4-16
respiratory bronchioles are where ___ takes place and are __-___
gas exchange, 16-23
respiratory bronchioles are broken down into (2)
- resp. bronchioles - 17-20
2. alveolar ducts - 21-23
alveoli function to INC
SA in lungs
alveoli are the site of
gas exchange
we have about ___ alveoli in the adult lung
300-500 million
O2-CO2 exchange occurs via ____ across the alveolar capillary membrane
diffusion
alveoli have THIN (.5-1.0 micrometer) membranes in order to ensure
distribution of O2 to RBC
V/Q =
ventilation/perfusion ratio, the ratio of ventilation to blood flow
what determines gas exchange in lungs
V/Q ratio
we can inc PO2 by giving O2, NOT by INC ___ to parts of the lung
ventilation
normal V/Q
1, PO2 = 100, PCO2 = 40
V/Q <1 (what we see clinically) has ___ ventilation and ___ perfusion
DEC ventilation, normal perfusion
V/Q >1 (less common) has ____ ventilation and ____ perfusion
normal ventilation, DEC perfusion (O2 is there, not able to attach to RBC)
with R-L shunt V/Q is
zero (alveoli filled with fluid)
examples of V/Q = 0
PNA, palm edema
with V/Q = 0, R-L shunt, PO2 doesn’t respond to
oxygen
dead space is ventilated but NOT
perfused
with INC dead space you have more air to clear from conducting airways and thus less
alveolar ventilation (less air to participate in gas exchange)
4 causes of hypoxemia
- V/Q <1
- hypoventilation (INC CO2)
- R-L shunt
- diffusion defect (thick alveoli)
hypercapnia is
INC CO2
2 causes of hypercapnia
- hypoventilation
2. dec V/Q
2 things that affect distribution of ventilation
- dec distensability (dec compliance, inc stiffness)
2. airway obstruction
compliance formula
change in volume/change in pressure
with restrictive disorders compliance
DEC (stiffer)
resistance formula
change in pressure/flow
extrathoracic upper airway obstructions are __ issues
inspiratory (stridor)
inhaling through a straw is like a ____ obstruction
extra thoracic upper airway
intrapulmonary airway obstruction is obstruction in the
lower lungs, bronchioles
with intrapulmonary airway obstruction air can flow in but
airway above obstruction collapses on expiration (expiratory wheezes)
ex of intrapulmonary airway obstruction
asthma/COPD
atelectasis is the collapse of
alveoli (sever obstruction that collapses lungs)
example of intrapulmonary airway obstruction is _____ in emphysema
hyperinflation (OVERCOMPLIANT tissue stretches permanently, IPA obstruction so bad you can hardly exhale)
increased airway resistance is from ____ and ____
bronchospasm and inflammation
increased airway resistance is common in (3) diseases
CF, asthma, chronic bronchitis
restrictive lung diseases are characterized by (5)
- dec compliance
- stuff lungs
- small lung vol
- difficult to INFLATE
- INC work of breathing
list the 6 restrictive lung diseases
- PNA
- aspiration PNA
- influenza PNA
- TB
- pulmonary fibrosis
- pulmonary edema
_____ is infection of the lung, filled with infected material (causes R-L shunt and dec V/Q)
PNA
PNA may also cause _____ and _____ leading to ____
bronchospasm and INC pulmonary capillary permeability leading to pulmonary edema
recurrent PNA is not normal, points to
underlying disorder like chronic lung disease (asthma, CF, immunocompromised)
aspiration PNA is
inhaled foods or gastric material in the lungs which fills alveoli
aspiration PNA is most common in those with
swallowing dysfunction (elderly, peds, neuro, GERD)
____ is a common site of aspiration PNA
RML
pulmonary fibrosis is caused by
multiple types of injury
clubbing is a sign of which restrictive lung disease
pulmonary fibrosis
pulmonary fibrosis is when
alveolar tissue is scarred leading to DEC lung vol and DEC compliance
untreated ____ leads to pulmonary fibrosis
interstitial pneumonitis
with pulmonary edema the fluid is in
the alveoli, not the capillary
obstructive lung diseases are characterized by
- INC resistance
- airway obstruction
- narrow airways
- DEC expiratory flow
- INC effort of breathing
list the 6 obstructive lung diseases
- asthma
- chronic bronchitis
- emphysema
- bronchiectasis
- CF
- pulmonary embolism
____ is the most common chronic lung disease
asthma
asthma is the
episodic narrowing of airways from inflammation and bronchospasm
primary problem in asthma is
airway mucosal inflammation causes swelling of airway lining and mucous secretion (release of cytokines and leukotrienes)
_____ is the primary physiologic abnormality in asthma
bronchoconstriction
with chronic bronchitis there is chronic ____ and _____ of ____
chronic infection and inflammation of bronchi and bronchioles
emphysema involves destruction of
alveolar walls (dec SA for gas exchange, dec elastic support of airways, airway obstruction, severe hyperinflation)
_____ is when airways lose cartilaginous support, collecting infectious materials, there is an abnormal dilation of bronchi
bronhiectasis
bronchiectasis is always due to
underlying disease
with bronchiectasis there is a massive risk of
hemoptysis
CF is autosomal
recessive
with CF multiple systems are involved by the most serious clinical problem and cause of death is
CF lung disease
GF gene is
CFTR protein (cystic fibrosis transmembrane conductance regulator protein)
in CF the ____ in exocrine cells does not work
chloride channel (cilia do not work, mucus with bacteria is stuck)
___ is a common cause of pulmonary embolism
DVT in femoral veins
a massive PE can occlude all or most of the pulmonary outflow tract leading to
sudden RHF and death
