Anatomy and Cell Biology 3309 Lecture Notes - Lecture 4: Respiratory Epithelium, Hyaline Cartilage, Lamina Propria
12 Jan 2017
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Document Summary
Respiratory epithelium is characterized best by the following functions: lubrication & motility. Intrapulmonary bronchus: there"s hyaline cartilage in segments, lung tissue surrounds it (must be within lungs so not trachea) Bronchioles is continuous with alveoli (air sacs) Site of gas exchange between air & blood. Epithelial lining has to be in close proximity to bvs for exchange. Pulmonary arteries (carrying o2 poor and co2 rich blood) form capillary networks surrounding alveoli. Need changes in pressure to take in/expel air for exchange. Inspiration: expansion of lungs: extend rib cage, diaphragm moves downwards. Lung is suspended in a sac with 2 layers: visceral layer. Pleura: surrounds lung cavity and is lined with mesothelium: film of liquid in bw the layers, the 2 layers of epithelium slide against each other as lung expands, accommodates shape changes as we breathe. No cartilage: large bronchi & trachea has less elastin + cartilage bc they always have to remain open to ensure entry/exit of gas.
