Test #3 for cardiopulmonary disease.

Define asthma.

Chronic airway inflammation + hyperreactivity; usually reversible obstruction.

Asthma vs COPD reversibility?

Asthma: variable/reversible. COPD: persistent, incompletely reversible.

Three causes of asthma airway narrowing?

Bronchospasm, mucosal edema, excess mucus.

Cause of bronchospasm?

Airway smooth muscle contraction.

Airway diameter ↓: resistance changes?

Resistance rises sharply as diameter decreases.

Define airway hyperresponsiveness.

Excessive bronchoconstriction to minor triggers.

Define an asthma trigger.

Stimulus causing bronchoconstriction or inflammation.

Define mucosal edema.

Swelling of airway lining from fluid.

Goblet cells in asthma?

Produce mucus; excess can plug airways.

Eosinophils in allergic asthma?

Release mediators; cause inflammation and tissue injury.

Define diapedesis.

WBC movement from blood vessels into tissues.

Define airway remodeling.

Chronic structural changes: fibrosis, thick walls, smooth muscle growth.

Cause of chronic airflow obstruction in asthma?

Airway remodeling narrows bronchi even between attacks.

Smooth muscle hypertrophy effect?

Thicker airway walls; greater narrowing with contraction.

Define asthma exacerbation.

Acute worsening of obstruction, inflammation, and mucus.

How does mucus cause air trapping?

Mucus blocks narrowed airways, limiting exhalation.

Why is expiration prolonged in asthma?

Small airways narrow further during exhalation.

Main asthma attack severity factors?

Bronchospasm, edema, mucus, inflammation, treatment response.

Result of repeated asthma attacks?

Fibrosis and smooth muscle growth → lasting obstruction.

Define bronchoconstriction.

Airway narrowing from smooth muscle contraction.

Mucociliary escalator function?

Cilia move mucus/particles toward the pharynx.

How can excessive airway mucus interfere with the mucociliary escalator?

Thick or excess mucus becomes difficult for the cilia to transport, increasing secretion retention and airway obstruction.

Immune system purpose?

Recognize, neutralize, and destroy pathogens.

Define antigen.

Substance recognized by immunity; can trigger a specific response.

Innate vs adaptive immunity?

Innate: fast/nonspecific. Adaptive: specific/memory.

How rapidly does innate immunity respond to foreign organisms?

Innate immunity begins responding immediately and can act against invading organisms within hours.

What is phagocytosis?

Immune cells engulf, ingest, and destroy foreign organisms or cellular debris.

Macrophage role in innate immunity?

Engulf pathogens/debris and coordinate immune responses.

How does intact skin contribute to innate immunity?

Intact skin provides a physical barrier that prevents microorganisms and harmful substances from entering underlying tissues.

How do stomach acid and digestive enzymes protect the body from infection?

They create a hostile chemical environment that destroys or inhibits many microorganisms entering the digestive tract.

What defensive functions do mucous membranes perform?

Mucous membranes secrete mucus and protective substances that trap, inhibit, and help remove microorganisms.

How do chemical compounds in the blood assist innate immunity?

Blood proteins and enzymes can identify, mark, damage, or help destroy invading organisms and recruit immune cells.

What occurs when innate immunity cannot adequately control an invading pathogen?

Innate immune activity activates and recruits the adaptive immune system to produce a more specific response.

Why is first adaptive response slower?

Antigen-specific lymphocytes must activate and multiply.

Two adaptive immunity branches?

Cell-mediated (T cells); humoral (B cells/antibodies).

What is cell-mediated immunity?

Cell-mediated immunity is an adaptive response involving T lymphocytes that recognize and attack infected or abnormal cells.

Which infection is most closely linked to cell-mediated immunity?

Intracellular infection, in which a pathogen is located or recausing inside host cells.

Where are T lymphocytes produced and where do they mature?

T lymphocytes originate in bone marrow and mature in the thymus.

What does helper T lymphocytes?

Helper T lymphocytes coordinate immune responses by releasing chemical signals that activate and direct other immune cells.

Define cytokines.

Immune signals that coordinate inflammation.

Excess cytokines cause what?

Recruitment of inflammatory cells can injure normal tissue.

Memory T-cell function?

Faster specific response on repeat antigen exposure.

Adaptive immunity: antigen specificity benefit?

Targets one antigen, avoiding indiscriminate activation.

Define humoral immunity.

B-cell antibodies against extracellular antigens.

What does extracellular mean for humoral immunity?

Extracellular refers to substances located outside cells, e.g., antigens circulating in blood plasma and other body fluids.

Where are B lymphocytes produced and mature?

B lymphocytes are produced and mature in the bone marrow.

How are B lymphocytes activated during a humoral immune response?

Helper T lymphocytes activate antigen-specific B lymphocytes, stimulating their multiplication and differentiation.

What are plasma cells?

Antibody-producing differentiated B cells.

Define immunoglobulins.

Antibodies secreted by plasma cells.

Memory B-cell function?

Faster antibody response upon re-exposure.

How does humoral immunity neutralize an extracellular pathogen?

Antigen-specific antibodies bind the pathogen or its products, helping neutralize their effects and facilitating elimination.

Most abundant blood antibody?

IgG (~80% in lecture).

What is the main protective role of IgG?

IgG protects against bacterial and viral infections and causes long-term immune defense.

Where is immunoglobulin A (IgA) found in high concentrations?

IgA is concentrated in mucosal secretions, e.g., respiratory mucus, saliva, tears, and gastrointestinal secretions.

How does IgA help protect the respiratory tract?

IgA helps neutralize pathogens at respiratory mucosal surfaces before they penetrate deeper tissues.

How can breastfeeding provide passive immune protection to an infant?

Breast milk contains protective antibodies, secretory IgA, that defend the infant's mucosal surfaces.

Where is immunoglobulin M (IgM) primarily found?

IgM is found mainly in blood and lymphatic fluid and is an important antibody produced early during a primary immune response.

Antibody associated with allergy?

IgE.

IgE role in allergic asthma?

Binds mast cells; allergen cross-linking triggers mediator release.

Least-understood immunoglobulin?

IgD.

What does Th1 helper T cells?

Th1 cells promote cell-mediated immune responses that important in combating infections.

What does Th2 helper T cells in allergic asthma?

Th2 cells promote allergic inflammation and stimulate B-cell antibody responses, e.g., IgE production.

Which imbalance is linked to an exaggerated Th2 response?

Increased Th2 activity favors allergic inflammation and IgE-mediated hypersensitivity responses.

Define hygiene hypothesis.

Less microbial exposure early in life may favor allergies.

What is atopy?

Inherited tendency toward allergic IgE responses.

Atopy prevalence (slide)?

Approximately 10–20%.

What are the two broad categories of factors linked to asthma development?

Host-related factors and environmental exposures.

Which host factors are emphasized?

Adaptive immune responses, genetics, and sex-related differences.

How does asthma prevalence differ between boys and girls during early childhood?

Asthma is more observed in boys than girls during early childhood.

How does the sex distribution of asthma change after puberty?

Asthma becomes more prevalent among females after puberty, possibly related in part to hormonal influences.

Which two environmental exposures receive particular emphasis as contributors to asthma development?

Airborne allergens and viral respiratory infections.

Which indoor allergens are identified as common asthma triggers?

Dust mites, cockroaches, animal dander, fungi, mold, and yeast.

Which outdoor allergens are identified as common asthma triggers?

Pollens and environmental fungi, molds, and yeasts.

Cockroach exposure: asthma mechanism?

Cockroach particles/droppings trigger allergy.

Why ask about asthma home exposures?

Identify triggers: dust, pets, pests, mold, smoke.

Which early childhood respiratory virus is emphasized as a risk factor for later asthma?

Respiratory syncytial virus (RSV).

Asthma/wheezing risk after childhood RSV admission?

Approximately 40%.

Other viruses linked to asthma wheeze?

Parainfluenza virus and rhinovirus.

Prematurity: later lung risks?

Immature lungs are vulnerable to injury and infections.

How does prenatal and postnatal tobacco smoke exposure on asthma risk?

Tobacco smoke exposure during pregnancy and infancy raises risk of childhood wheezing and respiratory problems.

How does parental smoking affect the risk of wheezing during an infant's first year?

Infants exposed to parental smoking are described as ~ four times more likely to develop wheezing during the first year.

How can cigarette smoking affect an adult patient's asthma treatment?

Smoking may increase asthma severity and decrease responsiveness to inhaled corticosteroid therapy.

What is occupational asthma?

Occupational asthma is asthma caused by exposure to a sensitizing substance or agent encountered in the workplace.

Which occupations are identified as having potential occupational asthma exposures?

Farming, agriculture, painting, cleaning, and plastics manufacturing.

Common workplace asthma triggers?

Grain dust, cleaning agents, paint, industrial inhalants.

Why may occupational asthma develop months or years after employment begins?

Repeated exposure to a workplace agent may produce gradual immune sensitization before clinically significant symptoms develop.

Which immune mechanisms can contribute to occupational asthma?

IgE-mediated responses and cell-mediated immune reactions.

What relationship exists between air pollution and asthma exacerbations?

Higher levels of indoor or outdoor air pollution are linked to increased asthma exacerbations and emergency department visits.

Which dietary factors are identified as potentially linked to asthma?

Milk or soy protein sensitivity, processed foods, low fruit and vegetable intake, and obesity.

Why encourage fruits/vegetables in asthma?

Antioxidants limit oxidative stress.

How can obesity contribute to airway inflammation?

Adipose tissue releases inflammatory mediators that cause systemic and airway inflammation.

Which beta-blocking medications are mentioned as potential problems for patients with asthma?

Propranolol and metoprolol, with particular concern for beta-blockade contributing to bronchoconstriction in susceptible patients.

Define exercise-induced bronchoconstriction.

Exercise-triggered transient airway narrowing.

What % of patients with asthma experience exercise-induced bronchoconstriction?

Approximately 90%.

Why is exercise-induced bronchoconstriction not always equivalent to an asthma diagnosis?

Exercise-induced airway narrowing may occur in individuals who do not otherwise have chronic asthma.

Exercise: what triggers bronchospasm?

High ventilation dries/cools airways, triggering constriction.

Stress: how can it trigger asthma?

Stress can alter autonomic/inflammatory responses.

Define perimenstrual asthma.

Worsening asthma around menstruation.

What % of women may experience asthma worsening linked to menstruation?

Approximately 30–40%.

Pregnancy effect on asthma?

Hormones/mechanics may worsen asthma in some pregnancies.