Respiratory Flashcards
How do you calculate total lung capacity?
Total lung capacity can be calculated as the sum of functional residual capacity and inspiratory capacity
TLC= FRC + IC
Increased FEV1/FVC suggests what type of disease.
Decreased FEV1/FVC
increased: Restrictive (fibrotic lung disease)
Decreased: can be seen in asthma, bronchospasm, emphysema, and old age
Small cell carcinoma arises from What type of cells?
What would you see on EM?
bronchial neuroendocrine cells.
Electron microscopy would reveal presence of intracytoplasmic neurosecretory vesicles.
Spirometry cannot measure what?
total lung capacity and the functional residual capacity
because they both require residual volume to calculate
How do you calculate alveolar ventilation?
V•A= (VT - VD) × f
by subtracting dead space (VD) from tidal volume (VT) and then multiplying by respiratory rate (f):
How will exposure of a pt’s blood sample to room air effect PO2, PCO2, and pH?
will result in a higher PO2, a lower PCO2, and higher pH than the actual values in the arterial blood.
Pt’s with COPD have decreased response to PaCO2 (central chemoreceptors) so what becomes more important for respiratory drive?
Hypoxemia i.e. Peripheral chemoreceptors (carotid body) sensing PaO2
Lecithin/sphingomyelin ratio is used to measure fetal lung maturity. What trends should you see throughout pregnancy?
should be about 1:1 until the middle of the 3rd tri; then type II pneumocytes begin secreting surfactant. Lecithin concentration increases sharply and sphingomyelin remains unchanged.
By 35 wks L/S ratio averages 2:1 or higher indicating lung maturity.
patients with persistent asthma can reduce the number and severity of acute asthma exacerbations by using what chronic therapy?
Inhaled corticosteroids reduce the inflammatory component of asthma.
Elastase is secreted by which respiratory cell?
Alveolar macrophages
What are the four stages of lobar pneumonia?
Congestion (first 24 hrs): affected lobe is red, heavy and boggy. micro shows vascular dilation, alveolar exudate contains mostly bacteria.
Red hepatization (2-3 days): red, firm lobe (liver like consistency). Alveolar exudate contains RBCs, neutrophils, and fibrin.
Gray hepatization (4-6 days): Gray-brown firm lobe. RBCs disintegrate. Alveolar exudate contains nuetrophils and fibrin
Resolution: restoration of normal architecture. Enzymatic digestion of the exudate
What are the stem cells of the lung?
Type II pneumocytes
also make surfactant
