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Asthma is characterized by bronchoconstriction and difficulty breathing.
Asthma is characterized by bronchoconstriction and difficulty breathing.
True
Emphysema is a reversible lung disease.
Emphysema is a reversible lung disease.
False
Chronic bronchitis is caused by chronic irritation and results in increased mucus secretion.
Chronic bronchitis is caused by chronic irritation and results in increased mucus secretion.
True
Leukotrienes are substances that inhibit inflammatory reactions.
Leukotrienes are substances that inhibit inflammatory reactions.
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Bronchoconstriction refers to the widening of the airways.
Bronchoconstriction refers to the widening of the airways.
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Histamine is a chemical mediator primarily involved in allergic reactions.
Histamine is a chemical mediator primarily involved in allergic reactions.
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Chronic Obstructive Pulmonary Disease (COPD) typically includes emphysema and asthma.
Chronic Obstructive Pulmonary Disease (COPD) typically includes emphysema and asthma.
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Prostaglandins are involved in various disease processes.
Prostaglandins are involved in various disease processes.
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Mucus production is essential for trapping foreign particles and protecting the lungs from infection.
Mucus production is essential for trapping foreign particles and protecting the lungs from infection.
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In asthma, mucus production decreases during exacerbations.
In asthma, mucus production decreases during exacerbations.
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Chemicals released during an inflammatory reaction help mediate asthma symptoms.
Chemicals released during an inflammatory reaction help mediate asthma symptoms.
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Histamine in the respiratory tract leads to bronchoconstriction and mucosal edema.
Histamine in the respiratory tract leads to bronchoconstriction and mucosal edema.
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Prostaglandins are solely responsible for mucus production in the lungs.
Prostaglandins are solely responsible for mucus production in the lungs.
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SRS-A is a potent bronchoconstrictor that promotes mucosal edema and leukocyte infiltration in asthma.
SRS-A is a potent bronchoconstrictor that promotes mucosal edema and leukocyte infiltration in asthma.
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Eosinophils are attracted to the site of injury or irritation by ECF-A released from mast cells.
Eosinophils are attracted to the site of injury or irritation by ECF-A released from mast cells.
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Hyperresponsiveness of airways due to mediators is a characteristic of asthma.
Hyperresponsiveness of airways due to mediators is a characteristic of asthma.
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COPD often leads to excessive mucus production and a persistent cough.
COPD often leads to excessive mucus production and a persistent cough.
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Airway obstruction in COPD is typically reversible with bronchodilators.
Airway obstruction in COPD is typically reversible with bronchodilators.
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Emphysema is characterized by inflammation of the airways and mucus gland hyperplasia.
Emphysema is characterized by inflammation of the airways and mucus gland hyperplasia.
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Symptoms of COPD tend to worsen over time and include shortness of breath and fatigue.
Symptoms of COPD tend to worsen over time and include shortness of breath and fatigue.
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Cigarette smoke is a primary cause of COPD, but air pollution has no significant influence.
Cigarette smoke is a primary cause of COPD, but air pollution has no significant influence.
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Wheezing, coughing, and chest tightness are common symptoms associated with COPD.
Wheezing, coughing, and chest tightness are common symptoms associated with COPD.
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COPD is solely triggered by genetic factors with no link to environmental irritants.
COPD is solely triggered by genetic factors with no link to environmental irritants.
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Chronic bronchitis involves increased mucus production and is primarily caused by long-term exposure to irritants.
Chronic bronchitis involves increased mucus production and is primarily caused by long-term exposure to irritants.
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Corticosteroids are used primarily to increase mucous production in the airways.
Corticosteroids are used primarily to increase mucous production in the airways.
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The sympathetic nervous system decreases bronchial smooth muscle tone.
The sympathetic nervous system decreases bronchial smooth muscle tone.
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Sympathomimetic bronchodilators increase the concentration of cyclic AMP in bronchial smooth muscle cells.
Sympathomimetic bronchodilators increase the concentration of cyclic AMP in bronchial smooth muscle cells.
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Leukotriene modifiers are included in the treatment regimen for conditions like asthma.
Leukotriene modifiers are included in the treatment regimen for conditions like asthma.
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Parasympathetic activation leads to bronchodilation and decreased mucous secretion.
Parasympathetic activation leads to bronchodilation and decreased mucous secretion.
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Cyclic AMP plays a crucial role by inhibiting the release of inflammatory mediators from mast cells.
Cyclic AMP plays a crucial role by inhibiting the release of inflammatory mediators from mast cells.
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Beta-agonists such as albuterol work by stimulating α-adrenergic receptors on bronchial smooth muscles.
Beta-agonists such as albuterol work by stimulating α-adrenergic receptors on bronchial smooth muscles.
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Treatment for respiratory conditions may include pulmonary rehabilitation.
Treatment for respiratory conditions may include pulmonary rehabilitation.
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Alpha 2 adrenergic receptors primarily increase sympathetic outflow.
Alpha 2 adrenergic receptors primarily increase sympathetic outflow.
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Beta 2 adrenergic receptors cause vasodilation in skeletal muscle, leading to greater physical strength.
Beta 2 adrenergic receptors cause vasodilation in skeletal muscle, leading to greater physical strength.
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Epinephrine has a short acting duration and must be watched for systemic adverse effects.
Epinephrine has a short acting duration and must be watched for systemic adverse effects.
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Orciprenaline is a selective beta agonist that only affects beta 2 receptors.
Orciprenaline is a selective beta agonist that only affects beta 2 receptors.
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Beta 1 adrenergic receptors are primarily located in the lungs.
Beta 1 adrenergic receptors are primarily located in the lungs.
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The onset of Orciprenaline when inhaled is greater than 5 minutes.
The onset of Orciprenaline when inhaled is greater than 5 minutes.
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Alpha adrenergic agonists lead to contraction of the bladder neck.
Alpha adrenergic agonists lead to contraction of the bladder neck.
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Beta adrenergic agonists can cause an increase in blood sugar levels.
Beta adrenergic agonists can cause an increase in blood sugar levels.
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Quick-relief medicines usually come in a green puffer.
Quick-relief medicines usually come in a green puffer.
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Short-acting beta-2 agonists, like Ventolin, last for 4 to 6 hours.
Short-acting beta-2 agonists, like Ventolin, last for 4 to 6 hours.
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Ipratropium is classified as a short-acting muscarinic antagonist (SAMA).
Ipratropium is classified as a short-acting muscarinic antagonist (SAMA).
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Formoterol is a short-acting beta-2 agonist (SABA).
Formoterol is a short-acting beta-2 agonist (SABA).
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Combivent is a combination of Ipratropium bromide and Albuterol.
Combivent is a combination of Ipratropium bromide and Albuterol.
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Long-acting bronchodilators can last up to 24 hours.
Long-acting bronchodilators can last up to 24 hours.
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Anticholinergic medications block the action of epinephrine on adrenergic receptors.
Anticholinergic medications block the action of epinephrine on adrenergic receptors.
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Salbutamol is classified as a long-acting beta-2 agonist (LABA).
Salbutamol is classified as a long-acting beta-2 agonist (LABA).
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Study Notes
Drugs and the Respiratory System
- Bronchodilators are drugs that relax bronchial smooth muscle, widening the lower respiratory passages to improve airflow.
- This improves breathing for people with conditions like asthma and COPD.
- Chemical mediators play a crucial role in asthma, triggering bronchoconstriction, mucosal edema, and infiltration of eosinophils.
- Key chemical mediators include histamine, ECF-A (eosinophilic chemotactic factor of anaphylaxis), and SRS-A (slow-reacting substance of anaphylaxis).
- Prostaglandins are released by cells in response to injury or irritation, causing swelling.
- SRS-A, a prostaglandin derivative, is a potent bronchoconstrictor and a mediator of asthma.
- Leukotrienes are formed from arachidonic acid and participate in inflammatory reactions, sometimes acting as a slow-reacting substance in anaphylaxis.
- Xanthines, like theophylline, are purine compounds used for bronchodilation, but their use is limited by a narrow therapeutic index.
- Mucolytics are drugs that liquefy or thin bronchial mucus. They help clear mucus buildup.
- Corticosteroids are synthetic substances used to treat inflammatory and allergic diseases, including conditions like asthma.
Terminology.
- Asthma is a respiratory disease characterized by bronchoconstriction, shortness of breath (dyspnea), and wheezing.
- COPD (Chronic Obstructive Pulmonary Disease) is a progressive lung disease which includes two main conditions: emphysema and chronic bronchitis.
- Emphysema is a condition that destroys the walls of alveolar sacs, reducing surface area available for gas exchange leading to difficulty breathing
- Chronic bronchitis is a respiratory condition caused by chronic irritation, which increases mucus secretion and causes degeneration of the respiratory lining.
- Chemical mediators are substances released during inflammatory and allergic reactions in the respiratory system.
Asthma
- Asthma is an inflammatory condition of the respiratory system characterized by shortness of breath and wheezing, caused by bronchiolar constriction.
- Asthma attacks can be triggered by irritants like dust, pollutants, noxious chemicals; exercise (especially in cold weather), respiratory tract infections, aspirin and related drugs (NSAIDS), and allergies to foreign proteins like pollen and animal dander.
- Asthma can include mucosal edema, increased bronchial mucus production, and depression of ciliary activity in the respiratory tract.
Ciliary Depression vs Mucus Production
- Ciliary depression refers to the reduced function of cilia, the tiny hair-like structures lining the respiratory tract, which are responsible for moving mucus.
- Mucus production is the secretion of mucus by the respiratory tract, essential for trapping foreign particles and protecting the lungs.
- In asthma, inflammation leads to increased mucus secretion, contributing to airway blockage.
- Impaired cilia function and increased mucus production both make breathing difficult.
The Role of Chemical Mediators in Asthma
- During an inflammatory reaction, chemical mediators are released from injured tissue, mast cells, and leukocytes in the respiratory tract.
- These mediators are responsible for asthma symptoms and complications.
- Histamine in the respiratory tract causes bronchoconstriction, mucosal edema, and eosinophil infiltration.
- Eosinophilic chemotactic factor of anaphylaxis (ECF-A) is released by mast cells to recruit eosinophils to injured tissue, exacerbating inflammation.
- SRS-A is a potent bronchoconstrictor, increasing mucosal edema and mucus secretion.
The Role of Chemical Mediators in Asthma
- Prostaglandins are widely distributed and released by cell membranes to respond to injury and irritation which can cause swelling.
- Prostaglandins are important mediators in the lung, and with asthma, the prostaglandin complex SRS-A (Slow Reacting Substance of Anaphylaxis) is involved. Made up of three leukotrienes, it is a potent bronchoconstrictor which causes long-term duration of symptoms, promotes mucosal edema, and produces leukocyte infiltration.
- These mediators are responsible for the characteristic airway hyperresponsiveness, mucus hypersecretion, and chronic inflammation observed in asthma.
Histamine
- Histamine is released from mast cells during allergic reactions.
- In the respiratory tract, histamine causes bronchoconstriction (narrowing of airways), mucosal edema (swelling of airway lining), and infiltration of eosinophils, increasing inflammation and damage to tissues.
ECF-A
- ECF-A (eosinophilic chemotactic factor of anaphylaxis) is released from mast cells to attract eosinophils, involved in the late-phase allergic response, and contribute to the chronic inflammation of asthma.
- Eosinophils release toxic proteins and enzymes that damage airway tissues, leading to ongoing inflammation and hyperresponsiveness, and a chronic, ongoing condition of asthma.
SRS-A
- SRS-A (Slow-Reacting Substance of Anaphylaxis), refers to leukotrienes, which are potent bronchoconstrictors.
- Prolonged bronchoconstriction is caused by leukotrienes.
- Leukotrienes promote swelling in the airway lining by increasing the leakiness of blood vessels, and increase mucus production, causing airway obstruction in asthma.
Asthma Therapy
- Goal of treatment for asthma is to stop or slow down the various chemical mediators causing asthma symptoms.
- Common drug classes used in asthma therapy include bronchodilators, corticosteroids, anti-allergics, and leukotriene receptor antagonists.
COPD
- COPD (Chronic Obstructive Pulmonary Disease) is a progressive lung disease caused by conditions like emphysema and chronic bronchitis which cause the respiratory system to change irreversibly.
- Symptoms can include a chronic cough, shortness of breath (SOB), increased susceptibility to infection, and restriction of physical activity.
- "Blue Bloaters" experience chronic bronchitis with mucus obstructing airways, lack of oxygen (O2), and a rise in carbon dioxide (CO2).
- "Pink Puffers" experience emphysema with permanent enlargement and destruction of alveoli and loss of elasticity which leads to difficulty exhaling.
Chronic Bronchitis
- Chronic bronchitis is characterized by chronic irritation and inflammation of the respiratory tract, often caused by cigarette smoke and other pollutants.
- Mucous buildup in the airways leads to chronic bronchitis. Secretions over time cause fibrotic changes in the respiratory lining, which makes it progressively harder to breathe. Cyanosis (bluish skin discoloration) can develop due to lack of oxygen (O2) and increased carbon dioxide (CO2).
Emphysema
- Emphysema is a condition in COPD that causes permanent enlargement of alveoli and destruction of alveolar walls, due to factors like smoking.
- Lungs lose elasticity, which makes expiration (exhaling) difficult, and the decrease of lung function makes everyday tasks hard.
COPD Therapy
- COPD therapy aims to provide relief from symptoms rather than reverse the permanent damage to the respiratory system.
- Treatment targets reducing dyspnea, improving quality-of-life, and limiting physical impairment.
Respiratory Conditions Comparison
- Asthma is a chronic inflammatory airway disorder characterized by reversible airway obstruction triggered by various factors, which can involve swelling, inflammation, increased mucous production.
- COPD is a progressive lung disease encompassing chronic bronchitis and emphysema.
- Chronic bronchitis is a type of COPD marked by chronic irritation, increased mucus secretion and fibrotic changes in the respiratory lining.
- Emphysema, another type of COPD, causes irreversible destruction of alveolar walls, making it hard to exhale.
Bronchodilators
- Bronchodilators are drugs that relax bronchial smooth muscles to open up the airways.
- They are used to treat conditions like asthma and COPD.
- Two main classes of bronchodilators are beta-2 agonists and anticholinergics.
Mechanism of Action of Bronchodilators
- Sympathomimetic bronchodilators (beta-2 agonists) stimulate beta-2 adrenergic receptors leading to an increased level of cyclic AMP, this increased level of cAMP causes the bronchiole muscles to relax.
- Anticholinergic bronchodilators block the action of acetylcholine on muscarinic receptors, decreasing the levels of cyclic GMP. This reduction in cyclic GMP prevents the muscles from contracting, causing bronchodilation.
Sympathomimetic Bronchodilators
- Sympathomimetic bronchodilators stimulate adrenergic receptors to increase cyclic AMP, which reduces the release from mast cells of the chemical mediators (histamine, leukotrienes, and prostaglandins). This in turn leads to vasodilation and bronchodilation.
- Beta-2 agonists like albuterol and salbutamol are known as B2 agonists. These are important drugs for conditions like asthma and COPD.
Role of Cyclic AMP
- cAMP is a secondary messenger vital in cellular processes, including bronchodilation.
- When beta-2 adrenergic receptors are activated, adenylyl cyclase converts ATP into cAMP.
- Elevated cAMP levels in bronchial smooth muscle lead to muscle relaxation (bronchodilation), which facilitates breathing.
Xanthine Derivative Bronchodilators
- Xanthine drugs, like theophylline, are bronchodilators that inhibit the enzyme phosphodiesterase.
- This enzyme normally deactivates cyclic AMP, but when it is inhibited, cyclic AMP levels rise, so muscle relaxation and bronchodilation occurs.
- However, these drugs have a narrow therapeutic index, requiring careful monitoring of doses to avoid toxicity.
Xanthine Derivative Bronchodilators: Why Not Used Commonly
- Xanthine derivatives like theophylline require considerably high doses to achieve therapeutic levels, making it prone to toxicity.
- Absorption varies greatly due to factors like food intake, gastric acidity, and other medications.
- Smokers may require higher doses due to faster clearance, while those with liver or heart diseases have slower clearance and also a higher risk of toxicity.
Sympathomimetic Bronchodilators
- Sympathomimetic agents work by stimulating adrenergic receptors, chiefly beta-2 receptors, which leads to bronchodilation.
- These receptors, when activated by these drugs, trigger a series of intracellular events leading to an increase in cyclic AMP (cAMP).
Adrenergic Receptors
- Adrenergic receptors are important for regulating bronchial tone, specifically the smooth muscles of the bronchioles.
- There are four main subtypes: beta-1, beta-2, alpha-1, and alpha-2, with varying locations and functions in the body.
- Beta-2 adrenergic receptors mediate bronchodilation and are a focus for bronchodilator medications like sympathomimetics.
Alpha and Beta Adrenergic Agonists
- Epinephrine (EpiPen) stimulates all alpha and beta receptors.
- The onset is immediate, and the duration is short-acting, although it has systemic adverse effects.
- The drug isn’t used selectively for the lungs because it has too many adverse cardiovascular effects.
Beta-Adrenergic Agonists (Non-selective)
- Non-selective beta-agonists like orciprenaline (Alupent) affect both beta-1 and beta-2 receptors.
- The onset of action is rapid (less than 5 minutes when inhaled), and the duration is relatively short (3-4 hours).
- While beneficial in short-term bronchodilation, their simultaneous stimulation of beta-1 receptors can include unwanted side effects like vasodilation (affecting blood vessels), tachycardia (increase heart rate), CNS stimulation, and metabolic changes (like increased blood sugar).
Beta 1 and Beta 2
- Beta-2 adrenergic receptors are predominantly found in the lungs and are crucial for bronchodilation—relaxing airways.
- Activation of beta-1 receptors, mainly present in the heart, results in an increase in heart rate and contractility.
- Selective beta-2 agonists are preferred for their focused effect on airways, reducing unwanted cardiac side effects.
Beta-2 Adrenergic Agonists (Selective)
- Beta-2 adrenergic agonists are used for shorter duration and acute treatment (Rescue/Reliever). Their shorter onset of action (minutes) and shorter duration (4–8 hours), make them suitable for treating acute bronchospasm, like in asthma.
- Examples include salbutamol, terbutaline.
Longer-acting Beta-2 Agonists (Selective)
- These are maintenance therapies and act more prolonged and at lower doses with fewer side effects.
- Examples include Formoterol, Salmeterol, and Indacaterol.
- They have a longer duration of action (12 hours) and are more effective at preventing bronchoconstriction.
Xanthine Derivative Bronchodilators
- Theophylline products are Xanthine derivatives and are bronchodilators used in the treatment of conditions such as asthma and COPD, often as a second-line therapy.
Information about Combination Therapies
- Combination therapies involve combining different drug classes to improve treatment outcomes by targeting various aspects of respiratory conditions like asthma or COPD.
- Combining bronchodilators with other medications often results in better control and fewer side effects compared to using a single medication.
Other Therapies
- Mucolytics like N-acetylcysteine (Mucomyst) break down mucus in bronchioles, which can be helpful in situations where mucus buildup is causing respiratory problems.
- Expectorants like guaifenesin (Robitussin) boost mucus production, making it easier to expel mucus from the airways.
- These treatments, especially mucolytics, are often used in hospital settings rather than as primary first-line treatment.
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Description
Test your knowledge on respiratory diseases such as asthma, emphysema, and chronic bronchitis. This quiz covers key concepts related to inflammatory reactions and the roles of various mediators like leukotrienes and histamines in respiratory health. Assess your understanding of Chronic Obstructive Pulmonary Disease (COPD) and its associated conditions.
