Exam 1 -- Pulmonary System Flashcards
What are the roles of the pulmonary system?
Acquire O2, get rid of CO2, and provide fast adjustment to blood pH.
What factors are important to good lung function?
Good blood flow, good ventilation, high lung surface area, and a match between where the air is in the lungs and which capillaries are carrying the blood.
True or false: as soon as the bronchi enter the lungs, air exchange begins to take place.
False; there is no air exchange through the first 18 bifurcations.
What features contribute to the lung’s immune response?
Lymph system is involved (enters at the hilum), cilia in the bronchi help get mucous and foreign substances out, cough reflex, mucous (to trap the foreign particles), and phagocytosis (if we can’t get the foreign particle out).
Alveoli have thin walls and a single layer of epithelial cells, to aid in gas exchange. What role does surfactant play in the alveoli?
It keeps the alveoli from collapsing and allows them to open easier.
Pulmonary capillaries surround each alveoli and are lined with a single layer of endothelial cells, to allow for easy and fast gas exchange. What influences capillary size?
If the O2 levels in the alveoli are low, or if they are high enough in the capillary, the lumen will contract because there is no reason to shunt blood that direction. Conversely, if there is high O2 in the alveoli but low in the capillary, the lumen will relax to shunt blood to where the O2 is. This is how blood flow is “matched” to where oxygen happens to be in the lungs.
True or false: the diaphragm is dome shaped with contraction, and returns to a flat shape upon relaxation.
False; it is dome-shaped at rest. When it contracts, it flattens and moves downward, to put negative pressure on the lungs during inspiration.
True or false: the accessory muscles of inspiration usually contribute only little to inspiration.
True; though some disease processes cause these to be more important.
Though expiration is mainly achieved through relaxation of the diaphragm, what inherent tendency of the lung tissue helps?
Elastic recoil acts to help the lungs snap back to their original shape.
What is considered a normal respiratory rate for an adult?
12-19 cycles per minute
What is considered a normal respiratory rate for a child?
up to 20 cycles per minute
What is considered a normal respiratory rate for a newborn?
up to 44 cycles per minute
How many breaths per minute is considered bradypnea? Tachypnea?
10 or less is bradypnea, 20 or greater is tachypnea.
What effect does the sympathetic nervous system have on the lungs?
Very mild arteriolar constriction, bronchial smooth muscle dilation, and inhibition of mucous glands.
What effect does the parasympathetic nervous system have on the lungs?
Bronchial smooth muscle constriction and stimulation of mucous glands.
Peripheral and central chemoreceptors both affect the respiratory rate. Which has the greater effect, and which blood gas is the major modifier of its actions?
Central have the most effect (85%). Central receptors are mainly influenced by blood CO2 levels. Higher CO2 levels or increased acidity trigger a reflex to increasing the breathing rate and depth.
Peripheral chemoreceptors would trigger increased respiration in resonse to what change in the blood?
Low O2 levels, high CO2 levels, or increased acidity.
What mechanoreceptors can help modify respiration? Which of these is involved in the matching of blood and O2-rich lung areas?
Stretch receptors in chest wall and airways (cause expiration if overinflation), irritant receptors in airways (cough), and J receptors (in lung periphery; these make the match between blood and lung).
What are the two common symptoms of lung disease?
Dyspnea (SOB) and chronic cough (phlegm and blood)
Chest pain is not one of the common signs of most lung conditions. Which three of the conditions discussed do feature chest pain?
Sarcoidosis, tuberculosis, and histoplasmosis (chronic pulmonary).
What testing can be used in the diagnosis of lung diseases?
X-ray (for structural abnormalities or trapped air), pulmonary angiography (for emboli), pulse oximetry (for hemoglobin saturation), spirometry (for rates, volumes, and easy of respiration).
Which lung volumes/capacities can be measured directly?
Expiratory reserve volume, tidal volume, and inspiratory reserve volume
Define: tidal volume
The volume of air expired and inspired with normal breathing.
Define: inspiratory reserve volume
The extra volume of air that can be brought into the lungs with effort.
Define: expiratory reserve volume
The extra volume of air that can be forcefully expelled from the lungs
Define: vital capacity
The volume of air that includes everything from the expiratory reserve volume through the inspiratory reserve volume. (VC = IRV + TV + ERV)
Which lung volumes/capacities are measured indirectly (mathematically)?
Functional residual capacity, residual volume, and total lung capacity.
Define: functional residual capacity.
The volume of air remaining in the lungs at the end of normal expiration.
Define: residual volume
The volume of air remaining in the lungs even after forceful expiration.
Define: total lung capacity
Maximum volume of lungs
Which blood gas can be used to determine if a respiratory acidosis is acute or chronic?
Bicarbonate: in an acute problem, it will be high. In a chronic problem, it will be normal or near normal.
Which blood gas can be used to determine if acidosis is due to a respiratory problem or a metabolic problem?
CO2–in a respiratory problem, it will be high. In a metabolic problem, it will be normal.
Which is more affected by obstructive pulmonary disease, expiration or inspiration?
Expiration.
True or false: COPD consists of emphysema, chronic bronchitis, and asthma.
False; asthma is not considered part of COPD.
Asthma is associated with what type of hypersensitivity?
Type I
What gender, age, and race is more likely to develop asthma? Least likely?
Female, child, black are more likely to develop asthma. Male, adult, Hispanic are less likely to develop asthma.
True or false: having severe asthma as a child slightly increases your risk of developing COPD as an adult.
Falase; it greatly increases the risk (32X)
What are the signs and symptoms of asthma?
Chronic cough, wheezing and shortness of breath are the classic triad. Also possible are tightness in chest, sympathetic discharge, tachypnea, and, in severe cases, cyanosis of nail beds, confusion, agitation, and nasal flaring.
Briefly outline the pathophysiology of asthma.
Asthmatics have 10x more mast cells than normal, so initiating factors cause a huge response in inflammatory response. Histamines, prostaglandins, tryptase, and leukotrienes cause bronchospasm, mucosal edema, and hypersecretion of mucous. Eosinophils releases proteins toxic to epithelial cells, which undergo metaplasia and become goblet cells and secrete more mucous. Proteins and collagens deposit in basement membranes, which thickens walls and narrows airways. Smooth muscle undergoes hyperplasia and has less beta receptors, which leads to increased bronchoconstriction.
What tests are used to diagnose asthma?
Spirometry with postbronchodilator response, pulse oximetry if acute, chest radiograph, and exercise spirometry.
Asthma can be categorized based on frequency of symptoms, lung function tests (FEV1), and peak flow variability. What are the severity classes of asthma?
Intermittent, mild persistent, moderate persistent, and severe persistent.
What medications can be used for treatment of asthma?
Anti-inflammatory meds (steroids, LT inhibitors, mast cell stabilizers, monoclonal antibodies), adrenergic agonists (to reduce bronchospasm, mucous production, and mast cell degranulation), anticholinergics (prevent smooth muscle contraction), glucocorticoids (decrease inflammatory response), and monoclonal antibodies (decreases inflammatory response by binding with IgE).
Which medications are the agents of choice to relieve bronchospasm?
Adrenergic agonists (beta 2 specifically).
Which short acting bronchodilator is the most commonly used?
Albuterol.
What is the advantage of inhalation powders over typical inhalers?
You don’t have to have “hand-breath” coordination.
Which adverse effect of adrenergic bronchodilators is paradoxical?
Bronchospasm can occur with repeated use due to sensitization (your body needs more of the drug to get the same result).
True or false: anticholinergics for asthma treatment are off-label.
True.
Anticholinergics prevent contraction of airway smooth muscle and are inhaled. Their onset is 3-4 weeks and they are typically less effective than beta 2 agonists.
Free card.
What are possible side effects of anticholinergics?
Blurry vision, dry mouth, HA, dizziness, cough, mydriasis, conjunctival hyperemia, angle closure glaucoma.
Which class of medication is first option when treating moderate to severe asthma?
Inhaled glucocorticoids, due to their ability to decrease remodeling. They can be either aerosol or powdered.
What are the most common adverse effects of glucocorticoids? Which of these effects are less likely with inhaled glucocorticoids?
Osteoporosis, impaired wound healing, increased risk of infection, HTN, edema, ulcers, psychoses, Cushing-like syndrome, oral candidiasis. Decreased growth in children, glaucoma, cataracts, and increased risk of DM are less likely in inhaled vs. oral glucocorticoids.
Inhaled glucocorticoids should be used with caution in patients with what conditions?
Parasitic infection, active or inactive TB, ocular herpes simplex, or increased IOP.
Leukotriene inhibitors are not used for immediate bronchodilation and are taken orally. Their most concerning side effect is impact on liver function, though they can cause HA, fever, sore throat, sinus infection, and SJS.
Free card.
Which medication for asthma is useful in children and pregnant women, and why?
Cromolyn is a mast cell stabilizer that is used for prophylaxis and is poorly absorbed, leading to few side effects.
Which medication for asthma is given as a subcutaneous injection? How does it work?
Omalizumab is a monoclonal antibody that binds to IgE and decreases its action. It decreases attacks experienced by patients, but has a risk of anaphylaxis.
What does alair bronchial thermoplasty involve?
A catheter is worked into the airways, which are heated to decrease their thickness and hyperresponsiveness.
What common medication should be avoided in asthmatics?
Aspirin; it blocks the prostaglandin side of the arachidonic acid metabolism pathway, shunting products toward the leukotriene side. Attacks can be triggered by aspirin (aspirin exacerbated respiratory disease (AERD).
What is the most common first symptom of COPD?
Dyspnea on exertion.
What is the #1 cause of COPD in the U.S.?
Smoking
How is the severity of COPD evaluated?
Questionnaires and spirometry/FEV1 tests.
True or false: emphysema and chronic bronchitis both start with narrowing and loss of small airways.
True; they eventually have much different results.
Emphysema is characterized by the formation of bullae. What are bullae, and how do they form?
They are large spaces where there should be many small alveoli. Repeated and prolonged inflammation causes release of proteolytic enzymes (such as tryptase) that digests the alveolar septal walls.
