CBIO 1000E Chapter Notes - Chapter 16: Alveolar Cells, Transpulmonary Pressure, Carbon Dust
Document Summary
16: think, secrete pulmonary surfactant lines the alveolus; made of phopholipids; lower surface tension; prevents, engulf external particles. Respiratory system is composed of three sections ventilation, gas exchange, & oxygen utilization upper respiratory tract nasal cavity, pharynx, larynx lower respiratory tract trachea, primary bronchi, lungs. Conducting zone structures the larynx, trachea, primary bronchus, 2nd/3rd bronchus - terminal bronchioles. Respiratory zones structures respiratory bronchioles and alveolar sacs (many alveolus) Function of conducting zone conducting air, warming, humidification, filtration, and cleaning. All the branches of the respiratory system increase the surface area. Type i alveolar cells make up 95-97% of alveolar cells. Characteristics of type i alveolar cells: base membrane fuses with capillary endothelial cells (reduce diffusion distance, gas exchange with blood. Characteristics of type ii alveolar cells: reabsorb na+ and h2o, preventing fluid buildup. Lungs can expand when stretched: defined as the change in lung volume per change in transpulmonary pressure dv/dp, the ease with which lungs expand under pressure.