The American black bear lived during the same period as short-faced bears (Arctodus simus and A. pristinus) and the Florida spectacled bear (Tremarctos floridanus). These Tremarctine bears evolved from bears that had emigrated from Asia to North America 7â8 ma.
A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric pressure.
The pleura includes two thin layers of tissue that protect and cushion the lungs. The inner layer (visceral pleura) wraps around the lungs and is stuck so tightly to the lungs that it cannot be peeled off.The outer layer (parietal pleura) lines the inside of the chest wall.The very thin space between the layers is called the pleural cavity. A liquid, called pleural fluid, lubricates the pleural cavity so that the two layers of pleural tissue can slide against each other.By Healthwise Staff.he outer layer (parietal pleura) lines the inside of the chest wall. The very thin space between the layers is called the pleural cavity. A liquid, called pleural fluid, lubricates the pleural cavity so that the two layers of pleural tissue can slide against each other. By Healthwise Staff.