respiratory anatomy Flashcards
Which part of the conducting zone has the least resistance, and why?
the terminal bronchioles have the least resistance. Even though they are much smaller than the bronchi or the trachea, there are many of them in parellel, which reduces overall resistance.
What are the special histologic features at the beginning of the conducting zone? To what region to they extend? (be thinking about things like cartilage)
The trachea has cartilage and goblet cells. Cartilage extends to the end of the bronchi
What kind(s) of epithelium lines the conducting zone of the respiratory tree? Where is airway smooth muscle found?
in the trachea and bronchus, we have ciliated pseudostratified columnar epithelium. these extend to the terminal bronchioles, then transition to cuboidal cells. Smooth muscle extends to the end of the terminal bronchioles.
What makes up the respiratory zone of the resp. system? What kind of epithelium?
respiratory bronchioles, alveolar ducts, alveoli
bronchioles have cuboidal cells. alveoli have simple squamous cells. No cilia. alveolar macrophages clear debris and help with immunity.
Compare type I and type II pneumocytes
type I pneumocytes: majority; squamous cells. line the alveoli. gas exchange occurs here.
type II pneumocytes: cuboidal. make surfactant to decr. surface tension and prevent alveolar collapse. also responsible for regenerating type I pneumocytes after injury
What are club (clara) cells?
between cuboidal and squamous. secretory cells. can make some components of surfactant, degrade toxins, and help support the lung.
What is surfactant? When does surfactant production begin in an embryo? When is this production mature?
helps prevent lung collapse. it is a mix of lecithins (dipalmitoylphosphatidylcholine)
production begins around 26 weeks, but may not be at mature levels until 35 weeks.
How do you test for lung maturity in the fetus?
ratio of lecithin to sphingomyelin ration > 2.0 in amniotic fluid.
describe the anatomy of the lung hilus
hilum has branches of pulm arteries, veins and bronchi. On the right, the pulmonary artery is anterior to the bronchus. on the left, the pulmonary artery is supperior to the bronchus (RALS).
What structures perforate the diaphragm? At what thoracic levels?
T8: IVC
T10: both vagus nerves and the esophagus
T12: aorta, thoracic duct, azygous vein.
Where is pain from the diaphragm referred?
shoulder (C5) or trapezius ridge (C3,4)
What is the vital capacity? Whats is the functional residual capacity?
vial capacity = tidal volume + inspiratory reserve + expiratory reserve
functional residual capacity = residual volume + expiratory reserve volume
What is the determination of physiologic dead space?
Vd =Vt X ((PaCO2 - PECO2)/PaCO2
vt is tidal volume
PaCO2 = arterial CO2
PECO2 = expired air PCO2
What is the minute ventilation?
total volume of gas entering the lungs per minute (Ve = tidal vol X resp rate)
What is the alveolar ventilation?
volume of gas per unit time that reaches the alveoli. VA = (Vt-VD) X RR
tidal volume - dead space vol X resp rate
