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
True or false: there is almost always significant disease overlap in both types of COPD
True
Asthma is a chronic inflammatory disorder marked by _________, ____________ airway obstruction
intermittent, reversible
IL 13 released by helper T cells in atopic asthma increases mucous production, which causes what?
Cough
Describe the 2 phases of atopic asthma
1 Early phase: Histamine > bronchospasm > wheezing
2) Late phase: structural changes
List structural changes associated with late phase asthma (atopic). Do these make it irreversible?
1) Hypertrophy of bronchial smooth muscle
2) Increased mucus glands
3) Increased vasculature and deposition of epithelial collagen
-This gives asthma and irreversible component in the late stage only
Non-atopic asthma:
1) What triggers it?
2) What are the mediators and Tx?
1) Viral illness and air pollutants
2) Many of the infl. mediators are the same + the Tx does not vary from atopic
What is the most common cause of asthma attacks?
Viral illnesses
What is it called when asthma attacks don’t respond to therapy? What are the 3 characteristics?
Status asthmaticus:
1) Hypercapnia > acidosis
2) Hypoxia
3) Fatality
What are the 2 general steps of bronchiectasis?
1) Obstruction or chronic/necrotizing infection
2) Inflammatory damage
Copious sputum is characteristic of what Dz?
Bronchiectasis
1) What two types of damage are associated with Idiopathic Pulmonary Fibrosis?
2) Describe IPF
1) Genetic + environmental damage
2) Bilateral interstitial fibrosis leading to restrictive
What are 4 things Idiopathic Pulmonary Fibrosis is linked to?
1) Genetic + environmental
2) Surfactant genes
3) Loss of telomerase and cell senescence
4) GERD
What are the 3 main causes of pneumoconioses?
1) Anthracosis (coal)
2) Silicosis
3) Asbestosis
Quartz is associated with what lung condition?
Silicosis
Asbestosis causes what?
Mesothelioma
What can asbestosis pts eventually experience?
Lung carcinoma; malignant pleura mesothelioma
*Risk of CA goes ways up if also smoking
List some key causes of pulmonary HTN
Lung diseases and/or hypoxia,including COPD, interstitial lung disease, and sleep apnea
List 4 types of pneumonia
1) Community Acquired Bacterial Pneumonia
2) Community Acquired Viral Pneumonia
3) Nosocomial Pneumonia (hospital acquired)
4) Aspiration Pneumonia
What is the most common cause of community-acquired bacterial pneumonia?
S. pneumoniae(the pneumococcus)
Common causes of viral pneumonia include what 3 things?
SARS Covid-2, influenza A and B, respiratory syncytial virus
Briefly describe TB pathology
1) Primary TB
2) Caseating granuloma
3) Latent stage (normal CXR, etc)
4) If reinfected or enters an immunosuppressed, can come back as “secondary TB”
5) Secondary TB usually = cavitary lesions
6) From here, TB can sometimes spread to the rest of the body
Briefly describe the scope of primary TB infections in previously unexposed unsensitized patients, and how common this type of TB is
Localized infection (Progressive primary TB is rare)
1) Secondary tuberculosis can result from ___________ of dormant primary infection or a re-infection by M. tuberculosis
2) Bacteria typically spread to _________ of lungs, causing ________________ bronchopneumonia.
3) What are 2 characteristics of secondary TB?
1) Reactivation
2) apex; granulomatous
3) Cavities; hemoptysis
List 4 Sx of secondary TB
Malaise, night sweats, weight loss, hemoptysis
Both progressive primary tuberculosis and secondary tuberculosis can result in ____________ seeding
systemic
Mnemonics for carcinomas are what?
“S” stands for “Sentral”
Squamous cell > scaley and obstructive
Adeno > grow slow
Small cell > small so it makes up for this with paraneoplastic disease
Cushing’s and SAIDH
Large cell, big deal because it grows fast
Malignant Mesothelioma:
1) Define it
2) It’s highly related to ______________ (80-90%)
3) Is there a latent period? Is it a primary or secondary condition?
1) Rare CA of the mesothelial cells of visceral or parietal pleura.
2) airborne asbestos
Latent period from exposure to development is 25-40 years
Secondary to causative driver mutations; once inhaled, asbestos fibers remain for live and do not diminish over time
1) What is the inheritance pattern of CF?
2) What causes it?
1) Autosomal recessive
2) Cystic fibrosis transmembrane conductance regulator (CFTR) gene
In CF patients, the CFTR protein chloride channel located in the _________ membrane of the __________ cells (lung, pancreas, sweat gland, vas deferens) are affected
apical membrane; epithelial cells (lung, pancreas, sweat gland, vas deferens)
The major features of classic cystic fibrosis are what?
chronic pulmonary disease and malabsorption
The CFTR protein maintains the hydration of secretions within the airways and ducts through the transport of ______________ across the cell membrane and inhibition of ____________ uptake
chloride; sodium
1) In CF pts, chloride channel is unable to open causing what to accumulate in the cell?
2) To balance the excess ions, the cells absorb excess what?
3) In secretory glands, this leads to what?
1) Chloride ions
2) Sodium
3) Decreases in fluid production.
CF pathogenesis:
1) Loss of CFTR chloride transport into the pancreatic duct impairs the ____________________ and leads to the retention of __________ enzymes in the pancreas. Damage from these retained enzymes eventually causes ____________ of the pancreas.
2) Without proper pancreatic enzyme action, what follows?
1) hydration of secretions; exocrine; fibrosis
2) Malabsorption
CF: In the absence of functional CFTR, the sweat has an increased content of what? Explain
Sodium chloride, and this is the basis of the historical “salty baby syndrome” and the diagnostic sweat chloride test
1) At birth, most infants present with chronic respiratory complaints and 15-20% present with meconium ileus due to what?
2) CF patients have _________ growth resulting from a combination of __________ calorie expenditure because of chronic lung infections and ___________ from pancreatic exocrine insufficiency
1) Thickened meconium or failure to pass meconium
2) poor growth; increased; malnutrition
More than 95% of male patients with CF are azoospermic because of what?
Congenital bilateral absence of the vas deferens (CBAVD)
CF:
1) Two heterozygous carrier parents have a ____% risk of having a child with cystic fibrosis
The heterozygous carrier frequency in the White population is approximately 1 in ____.
1) 25%
2) 50
