BIOL 102 Lecture Notes - Lecture 11: Pharynx, Air Sacs, Pulmonary Pleurae
Document Summary
Invaginations of the gut (esophagus: swim bladders floating. Restricted to one location circulatory system needs to carry gases inside thoracic cavity bounded by ribs and diaphragm. Separated by other body cavities by a diaphragm (synapomorphy to mammals) Inside double-walled sac pleural membranes: parietal (adheres to wall of thoracic cavity, visceral (adheres to lung) Fluid filled left and right pleural cavities prevent friction. Inflation of lungs is caused by negative pressure. Glottis closed when eating with epiglottis. Voice box vocal cords: flaps that vibrate with air and create sound due to a change in diameter. Not all mammals have vocal cords but can make noises. Internal pseudostratified ciliated epithelium (single layer) and produces mucus (goblet cells) trapping and discarding particles including pathogens. C shaped cartilaginous rings to prevent collapse of the end of tube from negative pressure from breathing. Branch to and within lungs increase sa. Bronchi: major air passageways of the lungs that lead to the bronchioles.
