Pulmonology Flashcards
(124 cards)
What is surfactant (chemically)?
Dipalmitoyl phosphatidylcholine
What is the shape of Type 1 and Type 2 pneumocytes respectively
Type 1 - squamous, Type 2 - cuboidal and clustered
What do clara cells do and what is their morphology?
Nonciliated columnar. Secrete component of surfactant, degrade toxins, act as reserve cells
What ratio in amniotic fluid is used to evaluate fetal lung maturity and what is the cutoff?
Licithin to spingomyelin ratio. If greater than 2 it indicates lung maturity
When does the lung epithelium become cuboidal ciliated?
After the terminal bronchiole
At what vertebral level does each of the three major structures pass through the diaphragm?
IVC - T8, Esophagus - T10, Aorta - T12
Formula for dead space
Vt * (PaCO2 - PeCO2) / (PaCO2)
What is responsible for the higher affinity for O2 of fetal hemoglobin?
A lower affinity for 2,3-BPG
Treatment for cyanide poisoning and what is the reasoning?
Nitrites. Oxidizes hemoglobin to methemoglobin (high affinity for cyanide). This keeps CN- away from cytochrome oxidase. Then give thiosulfate to bind cyanide
What does heme do regarding O2 and H+ in the lungs and tissue respectively?
Lungs - bind O2 and give up H+, Tissue - release O2 and pick up H+
Cause of primary pulmonary hypertension
Inactivation mutation of BMPR2 gene (normally inhibits vascular SM proliferation)
What type of cell mediates intimal fibrosis?
Smooth muscle cells
What is the pO2 in the LA relative to the end of the pulmonary capillaries and why?
Slightly lower in the LA because deoxygenated blood from bronchial veins mixes with oxygenated blood in the pulmonary veins
Formula for O2 content
(1.34 x Saturation) + pO2
Alveolar gas equation
PAO2 = PIO2 - PaCO2/R. Normally: PAO2 = 150 - PaCO2/0.8
Normal A-a gradient
10-15 mmHg
Causes of increased A-a gradient
Shunting, V/Q mismatch, fibrosis
Where in the lung are ventilation, perfussion, compliance, and pO2 respectively the highest?
Ventilation - highest at top lowest at bottom, Perfussion - highest at bottom, lowest at top. Compliance - highest at bottom, lowest at top. pO2 - highest at top, lowest at bottom
Give the relationship of PA, Pa, and Pv for each zone of the lung (Zone 1 is most superior, Zone 3 is most inferior)
Zone 1 - PA > Pa > Pv. Zone 2 - Pa > PA > Pv. Zone 3 - Pa > Pv > PA
What change is seen in renal excretion of bicarb at high altitude and what can you give to augment this?
Increased bicarb excretion, give acetazolamide to augment
What heart abnormality may be seen after living at high altitude for long time?
RVH due to pulmonary vasoconstriction
Imaging test of choice for pulmonary embolus
Helical CT
Virchows triad
Stasis, hypercoagulability, endothelial damage
Homans sign
Dorsiflexion of the foot leading to tender calf muscles, check in suspected DVT