Which type of cell is specialized to facilitate gas exchange? Type I pneumocytes Internal intercostal muscle fibres Type II pneumocytes External intercostal muscle fibres

Type I pneumocytes.

Explanation:

Type I pneumocytes are cells that cover more than 90% of the alveolar surface, due to the fact that they are very flattened and extensive, they fundamentally facilitate gas exchange. When the pneumocytes I contact the capillaries of the alveolar wall their basement membrane fuses with that of the endothelium, so that the gases only have to cross the cytoplasm of the pneumocyte, the fused basement membranes and the cytoplasm of the capillary endothelium, a set that measures less than 1 micron thick. In the rest of the alveolar wall, between the pneumocytes and the capillaries, a layer of interstitial tissue is interposed, with amorphous substance and fibrils, which performs a support function and, as it has lymphatic vessels, drains the fluid that permanently ultrafilters from the capillaries, thus preventing it from invading the alveoli.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

you must remain stopped until the stop signal is retracted and the red lights are turned off. approaching traffic in the opposite roadway of a divided highway shall not be required to stop, even if the school bus has the stop-arm extended and the alternately flashing warning signal lamps on.