Lecture 6.1 highlights Flashcards
The alveolar epithelium between the airspace and blood, consists of continuous layer of two cell types; what are they?
1) Type I pneumocytes which cover 95% of the alveolar surface
2) Type II pneumocytes that repair alveolar epithelium when it is damaged and create surfactant
Where are the alveolar spaces?
In between alveoli are “alveolar septa” (septum singular)
Alveolar spaces:
1) What is pulmonary interstitium made of?
2) What parts of the capillaries are here?
1) Elastic fibers, mast cells, and an assortment of miscellaneous cells and tissues
2) Capillary basement membrane, capillary walls, endothelium, blood
Atelectasis results in loss of lung volume caused by ______________ of airspaces
inadequate expansion
Fibrosis is characteristic of what type of atelectasis?
Contraction
Obstruction is characteristic of what type of atelectasis?
Resorption
Failure to breath deeply describes what type of atelectasis?
Compression atelectasis
Give an example of an airspace disease occurring in the alveoli that eventually results in the issue of fluid buildup in airspace
ARDS
How does ARDS happen? (6 steps)
Initial insult: Infxn, caustic substance, etc.
1) Inflammatory reaction
2) cytokines > neutrophils
3) PMN release caustic products:
4) Vascular leaking occurs, loss of surfactant
5) Fluid in the airspaces
6) Oxygen cannot diffuse
What are some long-term effects of ARDS?
Interalveolar fibrosis:
> Thickening of alveolar septa
> Chronic poor gas exchange
Describe the sequence of ARDS
1) Cytokines lead to neutrophil sequestration and activation
2) PMNs release their products
3) Tissue damage
4) Accumulation of edema fluid
5) Surfactant inactivation
6) Hyaline membrane formation
7) Macrophage-derived fibrogenic cytokines
What are the most common causes of ARDS?
1) PNA 35%-45%
2) Sepsis 30%-35%
3) Aspiration, trauma, pancreatitis, transfusion reactions
Restrictive lung diseases are characterized by reduced ______________ of lung and decreased total lung capacity
expansion
How much air you blow out in the first second is what?
FEV1
What are the 4 main types of obstructive disease?
Emphysema, chronic bronchitis, asthma, and bronchiectasis
True or false: It is possible to have emphysema all by itself
True: genetic disease: alpha-1 antitrypsin disorder
How do you get COPD/emphysema type?
1) Inflammatory mediators
2) Protease released
3) Elastin broken down
4) Acinar damage, alveoli are lost
5) # of alveolar capillaries diminished
6) Gas exchange reduced
7) Without elastic tissue, small airways collapse during expiration
8) Airflow obstruction
How do you get emphysema from alpha-1 antitrypsin?
1) Alpha-1 antitrypsin normally inhibits elastase (elastase breaks down elastin), but it’s underproduced [in lung], so it can’t do its job.
-Genetic disease present in lungs + liver
2) Elastase breaks down elastin in the lung
3) Acinus is affected as in normal emphysema – (but panacinar)
4) Obstructive disease
List the 3 secondary effects of emphysema
1) Pulmonary hypertension: physiologic shunting
2) Obstructive overinflation
3) Bullae
Chronic bronchitis is defined as the presence of persistent productive cough for ___ consecutive months in at least ___ consecutive years
3; 2
How do you get COPD/bronchitis type?
1) Hypertrophy of mucous glands
2) Mucin-secreting goblet cells ^
-Mucous plugging
3) Inflammation
-Local tissue destruction
-Fibrosis
Chronic bronchitis: In early stages, cough raises mucoid sputum, but airflow is not yet obstructed – pts may have ___________ airways, though, that lead to intermittent bronchospasm and __________
hyperreactive; wheezing
Significant outflow obstruction in late stage chronic bronchitis can lead to what 3 Sx?
1) Hypercapnia: can’t blow off the CO2
2) Hypoxemia: can’t intake 02
3) Cyanosis
List 2 Long-term Smoking Effects
1) Neutrophils are recruited
2) Transcription of mucin gene
