KINE 3012 Lecture Notes - Alveolar Cells, Intrapleural Pressure, Mast Cell

• School: York University
• Department: Kinesiology & Health Science
• Course: KINE 3012
• Professor: Tara Haas

Document Summary

The conducting zone determines air flow: trachea, bronchi, bronchioles, cartilaginous rings in the larger airways (trachea, bronchi, bronchioles) prevent collapse, low resistance pathway that warms, humidifies, and filters air. The respiratory zone enables gas exchange: respiratory bronchioles, alveolar ducts, alveolar sacs, there is an incredibly large surface area. All airways are lined with cuboidal epithelial cells: ciliated in the conducting zone: traps foreign particles and sweeps them up; also have mucus-secreting epithelial cells. Bronchioles are wrapped with smooth muscle cells: responsible for dilation and constriction (when you have asthma/allergic reaction it is likely a malfunction in these) Macrophages in the airways and alveoli remove airborne particles and bacteria. Type i alveolar cells are flat epithelial cells and compose most of the alveolar wall. Type ii alveolar cells are rounded epithelial cells (non-continuous line), found intermittently and secrete surfactant (important in inflating alveoli) Thin epithelial cells lining the alveoli and capillaries allow for easy gas exchange because it is so thin.