Alterations in Pulmonary Function Flashcards
Increased resistance to expired airflow due to reduction in caliber of airways
Obstructive Lung Disease
Obstructive lung disease caused by airway lumen
asthma, chronic bronchitis
Obstructive Lung Disease caused by airway wall
Asthma, Chronic Bronchitis
Obstructive Lung Disease caused by supporting structures surrounding the airway being damaged
emphysema
a disease of airway inflammation and variable airflow obstruction characterized by intermittent symptoms of wheezing, chest tightness, dyspnea, cough and bronchial hyperresponsiveness
asthma
Release of mediators due to response to allergen can cause what 3 things?
Alter airway smooth muscle tone and responsiveness
Induce mucus hypersecretion
Damage airway epithelium
Strongest identifiable predisposing factor for development of asthma is
Atopy
Atopy is the production of___antibodies in response to allergen exposure
IgE
What is the Atopic Triad
Asthma
Atopic Dermatitis
Allergic rhinitis
Samter’s Triad
Asthma
Nasal Polyps (sinusitis)
Aspirin Sensitivity
Why are BB a risk factor for asthma?
Many BB are nonselective… they can bind to B2 and cause bronchoconstriction
CELLS function as antigen-presenting cells that phagocytize foreign invaders
Dendritic
Once the dendritic cell engulfs the antigen, what is expressed on cell membrane
Antigen and MHC2 for Helper Tcell to recognize
essential to adaptive immunity as they activate B cells to secrete antibodies.
Helper T cells
Helper T cell are CD4 positive cells responsible for activation of __ cells and _______ T cells
Bcells
Cytotoxic T cells
Y-shaped proteins produced by B cells to identify and neutralize antigens in the body in mediating allergic reactions
IgE antibodies
white blood cells found in the connective tissues all over the body containing granules rich in histamine and leukotrienes
Mast Cells
What act on mast cells to cause them to undergo degranulation
IgE antibodies
white blood cells that play a significant role in the immune response to allergens and parasitic infections.
Eosinophils
What do Eosinophils release?
leukotrienes, cytokines, proteases
the release of leukotrienes and cytokines result in what response
proinflammatory
Release of proteases can do what?
directly damage airway epithelial cells resulting in chronic airway remodeling and hyperresposiveness over time.
Stages of Immune System Response to Allergens
- Allergens invades host
- Dendritic cell phagocytizes allergens
- expresses allergen antigen and MHC 2 complex
- Recognized by Helper T cell (CD4+) producing IL-4 and IL-5
- IL-4 stimulates production of IgE antibodies
- IgE antibodies stimulate degranulation of mast cells
- production of leukotrienes and histamines
IL-5 activates Eosinophils which causes the release of what 3 things
leukotrienes, cytokines, proteases
which proinflammatory Contracts airway smooth muscle, increase mucus secretion, activate inflammatory cells in airways
Leukotrienes
which proinflammatory is Involved in development of atopic state and chronic inflammatory process of asthma
Cytokines
which pro inflammatory causes Epithelial damage to airway tissue
Proteases
What are the histophologic features of asthma that reflect the disease
- Airway mucosa thickened, edematous, infiltrated with inflammatory cells
- Hypertrophied and contracted airway smooth muscle
- Bronchial and bronchiolar epithelial cell damage
- secretory gland hyperplasia and mucus hypersecretion
In asthma, airway inflammation, mucus hypersecretion, and smooth muscle hyperresponsiveness leading to bronchoconstriction results in what change to airway resistance?
Increased airway resistance
In asthma, is airway obstruction diffuse or not diffuse throughout the lungs?
diffuse
In asthma, is airway obstruction homogenous or not homogenous throughout the lungs?
not homogenous
what does airway obstruction to the lungs being diffuse but not homogenous result in?
nonuniformity of ventilation
In asthma, you can have abnormally low V/Q ratio or high V/Q ratio. Why is this?
A high V/Q is a result of a lot of ventilation (alveoli are getting big, compressing the vessels) but no perfusion (air trapping).
A low V/Q ratio is a result from low ventilation due to mucous covering the alveoli, but adequate perfusion where mucous is not. This results in HYPOXEMIA
What is an ominous sign during a severe asthma attack?
Hypercapnia
What are the Clinical manifestations of Asthma?
Dyspnea and chest tightness
Wheezing
Cough
Tachypnea and Tachycardia
Pulsus paradoxus
Hypoxemia
Hypercapnia and Respiratory Acidosis
Why does dyspnea and chest tightness happen asthma?
there is greater muscular effort to overcomve the increase airway resistance
hyperinflation from the airway obstruction leads to thoracic distension
Worsening obstruction leads to V/Q mismatching which leads to what?
Hypoxemia
What happens to lung compliance in patients with asthma?
it decreases due to thickening of the airway and increase work of breathing