In the respiratory system certain structures allow air to pass from the trachea to the lungs. They are lined with thin muscles and coated with epithelial cells. These structures are called bronchial tubes.
alveoli.
bronchioles.
lobules.

The potential to eradicate preventable diseases in the future depends on other societal factors that influence coordination and deployment of global health resources. for example, 70 confirmed cases of circulating vaccinederived poliovirus type 2 (cvdpv2) were reported syria, which is embroiled in war. where else are similar societal challenges preventing the eradication of polio? uzbekistan. nigeria. pakistan. a and c. b and c.