Flashcards in Final Exam Information Deck (268)
2 main causes of bronchodilation?
1. Circulating catecholamines such as epinephrine and norepinephrine
2. Non-parasympathetic nerve releases vasoactive intestinal peptide (VIP) and NO
What type of G-protein binds with Beta 2 receptors after episode and norepinephrine stimulation to cause bronchodilation?
7 steps of bronchoconstriction starting with CN X innervation of airway smooth muscle?
1. CNX innervating airway smooth muscle
2. Cholinergic nerve endings release Act to muscarinic receptor-3
3. M3 is coupled of Gq protein
4. Activated Gq protein activates phospholipase C (PLC)
5. PLC activates inositol triphosphate (IP3) - 2nd messenger
6. IP3 stimulates calcium release from SR
7. Increased calcium leads to bronchoconstriction
What type of response does coughing, allergy and infection cause?
Inflammatory response mediated by IgE
6 mediators of bronchoconstriciton
4. Platelet activtating factors
What do non-cholinergic C fibers release that cause bronchoconstriction?
1. Substance P
2. Neurokinin A
3. Calcitonin gene related peptide
What type of pattern do COPD patients show on PFT?
Describe the pathology behind COPD
Pathologic deterioration in elasticity or recoil within the lung parenchyma, which normally maintains the airways in an open position
What are the airways of COPD patients predisposed to?
Collapse during exhalation
What occurs with the gas velocity in COPD patients?
Increase in gas velocity in narrowed bronchiole, which lowers pressure inside the bronchiole and further favors airway collapse
What does bronchospasm and obstruction result from with COPD patients?
Increased pulmonary secretions
3 major characteristics of COPD patients?
1. Chronic cough
2. Progressive exercise limitation
3. Expiratory airflow obstruction
Patho behind Chronic Bronchitis? (Goblet cells and ciliary 5)
1. Increased mucous production
2. Loss of mucociliary clearance
3. Carina = cough
4. Inflammation causing more irritation
5. Air trapping
Patho behind Emphysema
1. Damage to collagen and elastin fibers
2. Airway almost collapse
3. Lung fibrosis and loss of elastic recoil is landmark sign of emphysema
Risk factors for COPD (4)
1. Tobacco = primary
2. Occupational exposure to dust; indoor and outdoor pollution
3. Respiratory infection
4. Genetic factors causing reduction in alpha 1 antitrypsin causing the enzyme to be too large
Clinical profile of COPD patients (9)
1. Progressive dyspnea
2. Chronic cough - mucous secretions
4. Expiratory airflow obstruction increases in severity
5. Decreased breath sounds
6. Expiratory wheezes
7. Increased A-P diameter
8. Hyperinflation in chest x-ray
9. Use of accessory muscles
PaCO2 characteristics of Emphysema
Normal to decreased
PaCO2 characteristics of Chronic Bronchitis
Mechanism of airway obstruction for Chronic Bronchitis
Decreased airway lumen due to mucus and inflammation
Mechanism of airway obstruction for Emphysema
Loss of elastic recoil
Hematocrit in Chronic Bronchitis patients
Hematocrit in Emphysema patients
Diffusing capacity in Chronic Bronchitis patients
Diffusing capacity in Emphysema patients
Cor pulmonale severity in Chronic Bronchitis
Cor pulmonale severity in Emphysema
Prognosis of Chronic Bronchitis patients
Prognosis of Emphysema patients
PaO2 characteristics in Chronic Bronchitis
Marked decrease (blue bloater)