ANSC 23000 Lecture 2: Pulmonary
27 Sep 2018
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Document Summary
Where oxygen diffuses out lumen of alveolus through interstitial space (diffusion barrier) into rbc (carbon dioxide opposite) Remember diffusion is passive, high to low concentration. Carbon monoxide performs same function but binds to hemoglobin better than oxygen, displaces oxygen which is how people die from carbon monoxide poisoning. Tidal system: air comes in and must exit same way it came (birds don"t have this) Contain macrophages to eat unwanted particles (dust, food) Type 2: surfactant secreting: around 22 generations of branching, air does not move in a straight path. Alveolar surface tension: thin film of water needed for gas exchange. Creates surface tension that acts to collapse alveoli and distal bronchioles. Bind to microorganisms, enhance adhesion, and phagocytosis of microorganisms by agglutination and opsonization. Premature infants that lack surfactant suffer from respiratory distress syndrome. Directly antimicrobial: lungs are the last organ to be developed in the developing fetus.
