Respiratory Flashcards
What is the major function of the lungs?
to replenish oxygen (O2) and remove carbon dioxide (CO2) from blood
What is pulmonary ventilation?
(commonly referred to as breathing) the process of air flowing into the lungs during inspiration (inhalation) and out of the lungs during expiration (exhalation)
Where does gas exchange occur? What properties do the alveoli require for this to happen?
- occurs in the lungs between alveolar air and the blood of the pulmonary capillaries.
- alveoli must be ventilated and perfused
What is ventilation (V) referring to in gas exchange?
refers to the flow of air into and out of the alveoli
What is perfusion (Q) referring to in gas exchange?
the flow of blood to alveolar capillaries
What zone of the lung does gas exchange occur?
occurs in the respiratory zone of the lung, where alveoli are present
What does the respiratory zone of the lung include?
- alveolar septa
- alveolar septum
- capillary endothelial cells
What does the alveolar septum contain?
- type I pneumocytes cover ~ 95% of the internal surface (lining)
- type II pneumocytes that secrete surfactant
- alveolar macrophages (also known as dust cells)
Lung function is physiologically divided into _____ volumes
four
What are the four volumes of the lung?
(1) expiratory reserve volume
(2) inspiratory reserve volume
(3) residual volume
(4) tidal volume.
What is the total of the four lung volumes equal to?
total lung capacity (TLC)
What is Pulmonary function testing (spirometry)
measures the rate at which the lung changes volume during forced breathing maneuvers
What are the lung capacities?
- Inspiratory capacity (IC)
- Total lung capacity (TLC)
- Vital capacity (VC)
What are the different lung volume measurements?
- Expiratory reserve volume (ERV)
- Inspiratory reserve volume (IRV)
- Residual volume (RV)
- Tidal volume (VT )
What are the frequently used Spirometric values of the lung?
- Forced vital capacity (FVC)
- Forced expiratory volume in one second (FEV1 )
- FEV1/ FVC ratio
What is forced vital capacity?
the total volume of air that can be exhaled during a maximal forced expiration effort.
What is forced expiratory volume in one second?
the volume of air exhaled in the first second under force after a maximal inhalation
What is the FEV1/ FVC ratio
the percentage of the FVC expired in one second
What are the airflow measurements of the lung?
Peak expiratory flow (PEF) (or peak expiratory flow rate [PEFR])
What is obstructive pulmonary disease?
any disease which causes a decrease in ventilatory function (airflow) due to (usually irreversible) obstruction of bronchi or bronchioles
What is Restrictive Pulmonary Disease?
any disease which causes a decrease in ventilatory function due to a decrease in the elasticity of the lungs themselves or caused by a problem related to the impaired expansion of the chest wall during inhalation
What is atelectasis?
(also known as collapse) is loss of lung volume caused by inadequate expansion of air spaces
What are the two major etiologic types of atelectasis?
- Obstructive atelectasis (resorption atelectasis)
- Nonobstructive atelectasis
What does obstructive atelectasis result from?
results from a blocked airway
What does nonobstructive atelectasis result from?
- Compression atelectasis (pleural effusion)
- Contraction atelectasis
- Abnormalities in surfactant
- Decreased ventilation of a portion of the lung
What is a pneumothorax?
Air in the pleural space, resulting in collapsing (atelectasis) of the lung
What are the classifications of pneumothorax?
- Primary pneumothorax
- Secondary pneumothorax
What causes Primary pneumothorax and Secondary pneumothorax
- Primary: idiopathic pneumothorax
- Secondary: emphysema or chronic bronchitis
What are clinical signs of a pneumothorax
- Sudden onset of pleuritic chest pain
- dyspnea
What is a hydrothorax?
A noninflammatory collection of serous fluid within the pleural cavities
What is the most common cause of a hydrothorax?
congestive heart failure
What do hydrothorax cause?
causes compression atelectasis
What is bacterial pneumonia?
Inflammation of the pulmonary parenchyma caused by an infectious agent (in this case, bacteria
What is etiology of bacterial pneumonia?
Bacteria cause acute, pyrogenic inflammation with exudates (fibrin, edema, neutrophils and macrophages) filling alveoli
What are the classifications of bacterial pneumonia?
- Lobar pneumonia
- Bronchopneumonia
- Interstitial (atypical) pneumonia
What is lobar pneumonia characterized by
consolidation (normal air filled space is filled with disease) of an entire lobe of the lung
What is Bronchopneumonia characterized by
scattered patchy consolidation centered around the bronchioles
What is Interstitial (atypical) pneumonia characterized by
- diffuse interstitial infiltrates
- Inflammatory cells and exudates are confined to alveolar walls only
What is the clinical presentation of bacterial pneumonia?
Varies with the cause of pneumonia, the patient’s age, and the clinical situation, but often includes:
- fever and chills
- productive cough with purulent yellow-green (pus) or rusty (bloody) sputum
- tachypnea with pleuritic chest pain
- decreased breath sounds
- elevated WBC coun
What is aspiration pneumonia?
sub-type of bacterial pneumonia resulting from entry (aspiration) of bacterial-colonized oropharyngeal or upper gastrointestinal contents
Aspiration pneumonia classically presents as what?
right lower lobe infection / pneumonia
What is viral pneumonia, and what are the most common causes?
- lung infection caused by any of a large number of viral pathogens
- influenza types A and B, the respiratory syncytial viruses (RSV), & coronavirus
What are lung abscess?
localized area of suppurative liquefaction necrosis within the pulmonary parenchyma
What causes lung abscess?
Aspiration of infective material from carious teeth or infected sinuses or tonsils are the most common cause of lung abscess, with periodontal disease being a major predisposing factor
What is the clinical presentation of lung abscess?
- Prominent cough that usually yields copious amounts of foul-smelling, purulent, or sanguineous sputum
Where are lung abscess most common
more common in the right lower lobe of the lung
What is pulmonary tuberculosis?
an infection of the lung and, occasionally, surrounding structures, caused by the bacterium Mycobacterium tuberculosis (MTB)
What are the two major forms of tuberculosis infections and the characteristics?
- Primary (acute) tuberculosis: develops in a previously unexposed and therefore unsensitized patient
- Secondary (reactivation) tuberculosis: reactivation of dormant primary lesions many decades after initial infection, particularly when host resistance is weakened.
What is the main cause of tuberculosis?
Mycobacterium tuberculosis (MTB), strict aerobe bacilli that are slow-growing and acid-fast
What are different classifications of tuberculosis?
- Pulmonary TB (most common form)
- Miliary (disseminated) pulmonary TB
- Systemic miliary TB
- Endobronchial, endotracheal, and laryngeal TB
When does miliary pulmonary TB occur?
when MTB bacilli reach the bloodstream through lymphatic vessels and then recirculate to the lung via the pulmonary arteries
When does systemic miliary TB occur?
when the MTB bacilli spread hematogenously throughout the body
How do the MTB organisms enter the body in Primary (Pulmonary) Tuberculosis?
- enter the body by inhalation, then commonly deposited in alveoli
In Primary (Pulmonary) Tuberculosis, sensitized _____ cells are lacking. The MTB organisms _____ freely and enter the bloodstream and lymphatics and disseminate to other parts of the body during the first few ______ after infection
- CD4+ T
- multiply
- weeks
What type of immunity is important in primary tuberculosis?
cell mediated immunity
What is a ghon focus?
an area (tubercle) of gray-white granulomatous inflammation with consolidation develops in the lung as the immune response develops to MTB
In most cases, the center of the Ghon focus tubercle undergoes _____ necrosis
caseous
Tubercle MTB bacilli, either free or within phagocytes, drain to the ____ lymph nodes, which also often caseate
regional hilar
What is the ghon complex?
The combination of Ghon focus parenchymal lung lesion and regional hilar lymph node involvement
T/F In about 95% of normal adults development of cell-mediated immunity does not control the MTB infection, and it follows a self-limited course
FALSE
In about 95% of normal adults development of cell-mediated immunity controls (but does not eliminate) the MTB infection, and it follows a self-limited course
What happens to the lesions in the lung and lymph nodes of the ghon complex as cell mediated immunity develops?
undergoing shrinkage, fibrous scarring, followed by radiologically detectable calcification (called the “Ranke complex”), and despite seeding of other organs, with MTB no lesions (granulomas) develop
Regardless of the organs involved, all ______ granulomas have similar features and follow the same progression
tuberculous
Histologically, what do sites of active MTB infection undergo?
characteristic inflammatory reaction marked by the presence of caseating (and noncaseating) granulomas, which consist mainly of epithelioid histiocytes (macrophages) and multinucleate (Langhans’ giant cells), that eventually undergo fibrosis and calcification
What happens if a patient with MTB infection develops a decrease in their immune function
the dormant MTB organisms may break out of the fibrosed and calcified TB granuloma and cause serious (reactivation) tuberculous infection
Is progressive primary tuberculosis common?
- TB infection takes this course in less than 10% of normal adults, but it is common in children under 5 years of age.
- In adults, progressive primary tuberculosis most commonly occurs in patients with suppressed or defective immunity
What does secondary (reactivation) tuberculosis usually result from?
reactivation of dormant, endogenous tubercle bacilli in a sensitized patient who has had previous contact with the tubercle bacillus
How long after primary infection does secondary tuberculosis develop?
Secondary tuberculosis may develop any time after primary infection, even decades later
What are responsible for a significant number of cases of secondary tuberculosis?
immunosuppressive disease (e.g., HIV/AIDS) or immunosuppressive drug therapy
Classic symptoms of TB include what?
- Cough is nearly universal (purulent secretions, appearance of blood streaking or gross hemoptysis)
- Sweating / drenching night sweats
- malaise, fatigue, weight loss, non-pleuritic chest pain and dyspnea
What are common signs of tuberculosis?
- Fever
- Rales (small irregular clicking, bubbling, or rattling breath sounds)
- rhonchi (low pitched continuous breathing sounds that resemble snoring or gurgling)
- wheezing
In the past, progressive tuberculosis could lead to a cachectic-like wasting termed “_______”
consumption
Fungal infections evoke what type of hypersensitivity reaction? What do they result in?
- type IV (T cell-mediated) hypersensitivity reaction
- typically result in granulomas in the lung, with little or no caseation
What causes Histoplasmosis?
What causes Coccidioidomycosis?
What causes Cryptococcosis?
- Caused by Histoplasma capsulatum
- Caused by Coccidioides
- Caused Cryptococcus neoformans
What causes North American Blastomycosis?
What causes aspergillosis?
- Caused by Blastomyces dermatitidis
- Caused Aspergillus species mold
What is Sarcoidosis (Boeck’s disease)?
A chronic multisystem granulomatous disease, with noncaseating granulomas
What do tissues involved in sarcoidosis contain?
- well-formed noncaseating (non-necrotizing) granulomas
- multinucleated Langhans’ giant cells
What are clinical manifestations of sarcoidosis?
- Lung involvement occurs in more than 90% of patient
- Uveoparotid fever
- bilateral enlargement of the parotid or salivary glands, facial nerve paralysis and anterior uveitis
What is Chronic obstructive pulmonary disease (COPD)?
an umbrella term, usually refers to a mixture of chronic bronchitis and emphysema
What is chronic bronchitis characterized by?
- excessive secretion of bronchial mucus resulting in obstruction of small airways
- manifested by productive cough for 3 months or more in at least 2 consecutive years
What is emphysema characterized by?
loss of lung elasticity and destruction of lung parenchyma
What is the biggest risk factor for COPD?
Cigarette smoking (and age) account for more than 85% of the risk of developing COPD in the USA
What are other risk factors for COPD
- Air pollution and occupational exposure
- Hyper-responsive airways
- Alpha1 -protease inhibitor (API) or alpha1 -antitrypsin [ATT]) deficiency
- Homozygous API (ATT) deficiency
How does air pollution and occupational exposures increase your risk of COPD?
- indoor air pollution
- airborne chemical vapors / fumes or biologically inactive dusts (e.g., dusts from cotton, cadmium, coal, silica)
How does a Homozygous API (ATT) deficiency increase your risk of COPD?
results in premature development of severe emphysema
What is emphysema characterized by pathologically?
- dilatation of the acinar air spaces due to destruction of the interalveolar septa
- proteolytic enzymes
In emphysema, what are consequences of septal destruction?
- Elasticity of lung tissue is reduced causing airways to collapse during expiration
- surface area and amount of capillaries available for gas exchange is greatly reduced
- progressive dyspnea and hypoxemia and hypoxia
In advanced emphysema, there is increased ______ pressure (_____ hypertension) and eventual cor pulmonale
- pulmonary artery
- pulmonary
Two major forms of emphysema are?
- Centriacinar (centrilobular) emphysema: most common form
- Panacinar (panlobular) emphysema
Where are lesions the worst in Centriacinar (centrilobular) emphysema
lesions are more common and severe in the upper lung lobes
What is the distinctive feature of centriacinar emphysema?
- central or proximal parts of the acini, formed by respiratory bronchioles, are affected, while distal alveoli are spared
- associated with cigarette smoking
What does Panacinar (panlobular) emphysema most often affect?
more commonly in the lower lung zones
What are distinctive features of Panacinar (panlobular) emphysema
- acini are uniformly enlarged, from the level of the respiratory bronchiole to the terminal blind alveoli
- associated with alpha1 -antitrypsin deficiency
Chronic bronchitis is primarily attributed to long-standing irritation of the airways from what?
airway irritants, especially cigarette smoke
The distinctive feature of chronic bronchitis is what?
hypersecretion of mucus, beginning in the large airways
Other pathologic changes of chronic bronchitis include? (5)
- Hypertrophy of mucous glands and increase in mucin-secreting goblet cells
- increased mucus viscosity and volume → impairment of pulmonary defense mechanisms
- airway wall inflammatory cell populations
- Retained mucus secretions plus inflammation
- Impairment of pulmonary defense mechanisms
What does retained mucus secretions plus inflammation in chronic bronchitis account for?
reduction in small airway function (significant airflow obstruction)
What does impairment of pulmonary defense mechanisms account for in chronic bronchitis?
increase in the frequency of lower respiratory bacterial and viral infections
Most patients with COPD have pathologic evidence of what?
both disorders (i.e., concomitant chronic bronchitis and emphysema)
How old are most patients with COPD? What are some of the symptoms?
present in the fifth or sixth decade of life complaining of excessive cough, sputum production, and shortness of breath (dyspnea)
What are signs and symptoms of COPD?
- Cyanosis with chronic (usually productive) cough, tachypnea, tachycardia, and fatigue.
- Dyspnea (that is persistent and progressive).
- Pursed-lip breathing with use of accessory muscles for respiration, decreased breath sounds, and wheezing
- Chronic sputum production.
- Chest wall abnormalities
What are some chest wall abnormalities of COPD?
hyperinflation, increased anteroposterior diameter of the chest, [i.e., “barrel chest”], and a protruding abdomen
COPD has a ______ progressive course with frequent _____ exacerbations
- chronic
- acute
What characterize the late stage of COPD?
Pneumonia, pulmonary hypertension, cor pulmonale, and chronic respiratory failure
What is the reference standard for measuring the severity of COPD
Spirometry
What happens to FEV1 and FVC when doing a spirometry measurement of a COPD patient?
abnormally decreased FEV1 and FVC is required to confirm diagnosis
Besides spirometry, what are other diagnostic features of COPD?
- Oximetry (blood oxygen saturation): hypoxemia
- Arterial blood gases: hypercapnia
- Chest radiograph: hyperinflation of the lungs with flattening of the diaphragm
What is bronchiectasis?
not a specific disease, but consequence of another disease (most often an infection) that results in dilatation of the bronchi or bronchioles
What are some of the common causes of bronchiectasis?
- previous infections
- cystic fibrosis
- COPD
What is the clinical presentation of bronchiectasis
- Chronic cough, typically with expectoration of purulent sputum
- frequent bronchitis or pneumonias
What is asthma?
an inflammatory disease of the airways
Asthma is characterized by what?
recurrent episodes of airway obstruction due to bronchospasm
In asthma, the airflow obstruction is usually ______, either spontaneously, or through pharmacologic therapy
reversible
Asthma can be classified by etiology into two general categories. What are they?
- extrinsic (allergic, atopic) asthma
- intrinsic asthma
What is the most common form of asthma? Whay type of hypersensitivity is it?
- Allergic or extrinsic asthma
- type I hypersensitivity
What does binding of the allergens to sensitized IgE attached to the surface of mast cells trigger in asthma?
degranulation and the release of histamines, bradykinins, leukotrienes (LTC4, D4, and E4), and prostaglandin D2.
What does the release of histamines, bradykinins, leukotrienes (LTC4, D4, and E4), and prostaglandin D2 lead to in asthma?
- intense inflammatory reaction
- spasm (contraction) of the airways smooth muscle (bronchospasm)
- increased mucus secretion with plugging of small airways
What are the subtypes of intrinsic asthma?
- Exercise-induced asthma
- Occupational or environmental asthma
- Drug-induced asthma (or triad asthma)
What are some things that can make exercise induced asthma worse?
- Hyperventilation of cold, dry air
- emotional stress
What is drug induced asthma caused by?
a combination of bronchospasm, aspirin (and some nonsteroidal anti-inflammatory drugs [NSAIDs], sulfites, sensitivity, and rhinitis, nasal polyps, and urticaria
What is considered a characteristic feature of asthma (regardless of overall asthma severity)
Persistent (chronic) airway inflammation
What does persistent (chronic) airway inflammation consist of?
infiltration of the airways by inflammatory cells, hypertrophy of the airway smooth muscle, and thickening of the lamina reticularis
What are the most striking findings in individuals experiencing an severe asthmatic episode (“asthma attack”)?
- Lungs that are distended due to air trapping
- Occlusion of bronchi and bronchioles by thick, tenacious mucous plugs
- Numerous eosinophils and Charcot-Leyden crystals
What do the mucous plugs found in asthma attacks (severe asthmatic episodes) contain?
mucus, serum proteins, inflammatory cells, and cellular debris, which includes desquamated epithelial cells often arranged in a spiral pattern (Curschmann spirals)
Signs and symptoms of an asthmatic episode are generally characterized by what?
wheezing, dyspnea, coughing, and a feeling of tightness in the chest
What are common signs of more severe asthma attacks?
sitting upright and leaning forward (“tripoding”), and use of accessory muscles of respiration
T/F The frequency of asthma symptoms is highly variable
True
T/F Asthma symptoms are frequently worse during the day
FALSE
Asthma symptoms are frequently worse at night
What is Status asthmaticus
- A medical emergency
- It is an extreme form of acute asthma exacerbation characterized by hypoxemia, hypercarbia, and secondary respiratory failure
Patients with extrinsic (allergic) asthma will usually show elevated levels of _____ and ____ skin tests to various allergens
- serum IgE
- positive
During an asthmatic episode (“asthma attack”), what will spirometry show?
- Decreased FEV1 , FVC, FEV1 /FVC ratio, and peak expiratory flow (PEF)
- Reversibility of airway obstruction is usually seen after the patient inhales a short-acting bronchodilator drug
What is Asthma-COPD Overlap (ACO) (or Asthma-COPD overlap syndrome [ACOS])
It identifies a subgroup of smokers with COPD that share some pathogenic and inflammatory characteristics with asthma and that tend to have a more severe disease manifestations than just COPD alone
What is the most common cause of cancer mortality in the U.S.
lung cancer
What are key risk factors for lung cancer?
cigarette smoke, radon, and asbestos
______% of lung cancer occurs in smokers.
Cancer risk is directly related to the _____ and _____ of smoking
- 85%
- duration
- amount
What are the major histologic types of carcinomas of the lung?
- Non-small cell lung carcinomas (NSCLC)
- Small cell lung carcinoma (SCLC)
What are examples of Non-small cell lung carcinomas (NSCLC)?
- adenocarcinoma (~ 50%)
- squamous cell carcinoma (~ 30%)
- large cell neuroendocrine carcinoma (~ 5%)
What type of carcinoma has the strongest association with smoking?
small cell lung cancer carcinoma (SCLC)
What does the term bronchogenic carcinoma describe?
- Once used to describe only certain lung cancers arising from the epithelium of the bronchus or bronchiole.
- However, today it can refer to any type of SCLC and NSCLC
What are some clinical presentations of lung cancer?
symptoms are nonspecific:
typically include cough, hemoptysis, dyspnea, unintentional weight loss and post-obstructive pneumonia
What are Pneumoconioses: Silicosis, Anthracosis, Asbestosis, Berylliosis
Chronic fibrotic lung diseases caused by the inhalation of inert inorganic dusts
What is the exposure for anthracosis?
carbon dust
What is the exposure for silicosis
silica
what is the exposure for berylliosis
beryllium
what is the exposure for asbestosis
asbestos fibers
What are the pathological findings of Anthracosis
- Mild exposure = anthracosis
- Major exposure diffuse fibrosis (‘black lung disease’)=
What are the pathological findings of Silicosis
Fibrotic nodules in upper lobes of the lung
What are the pathological findings of Berylliosis
Non-caseating granulomas in the lung
What are the pathological findings of Asbestosis
Fibrocalcific lesions (plaques) of lung and pleura with increased risk for lung carcinoma and mesothelioma
What are asbestos bodies?
- also called ferruginous bodies
- long, golden-brown fibers with associated iron coating
What does silicosis increase the risk for
TB
What does berylliosis increase the risk for?
lung cancer
