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.
According to FOA, the causes of land degradation can be divided in to 03 categories: a. Direct causes â unsustainable land use and inappropriate land management practices b. Underlying causes â the reasons for which inappropriate types of land use or management are practiced. c. Natural hazards â relate to factors of the biophysical environment that increase the