Air is then breathed into the windpipe and lungs, while the mucus is swallowed (figure 3). Other. Other interesting structures associated with the nasal and sinus tract: Tear duct (called the nasolacrimal duct): drains tears from the inside corner of the eye into the nasal cavity (figure 1).
Human activity is the main cause of soil degradation. Agriculture plays a large part in soil degradation, especially clearing, irrigation, the spreading of chemical fertilizer â¦ s and pesticides, overgrazing and even the passage of heavy farming equipment. Tillage and the clearing and deforestation of large plots of land also lead to soil degradation.
The degradation was the result of loss of vegetation due to deforestation, cutting beyond permissible limits, unsustainable fuel wood and fodder extraction, shifting cultivation, encroachment on forest lands, forest fires and overgrazing, the report -- jointly prepared by the environment ministry and the Indian Council of Forestry Research and Education -- said.