Explain how respiratory tract diseases are passed on from one person to another

The discussion assignment provides a forum for discussing relevant topics for this week based on the course competencies covered.
For this assignment, make sure you post your initial response to the Discussion Area by the due date assigned.
To support your work, use your course and text readings and also use outside sources. As in all assignments, cite your sources in your work and provide references for the citations in APA format.
Start reviewing and responding to the postings of your classmates as early in the week as possible. Respond to at least two of your classmates. Participate in the discussions (which are your peer responses) by providing a statement of clarification, providing a point of view with a rationale, challenging an aspect of the discussion, or by indicating a relationship between two or more lines of reasoning in the discussion. Your peer responses should be about 150 words each, follow APA format, and include academic citations. Complete your participation for this assignment by the end of the week.
Respiratory Tract Infections
Respiratory tract infections are the chief cause of absenteeism in schools as well as places of work. From the common cold to the more serious bronchitis, respiratory tract infections are usually infectious and thus easily passed on from one person to another.
Your assignment is to research on diseases of the respiratory tract, using the South University Online Library or the Internet. Based on your research, respond to the following:

• Classify respiratory tract diseases, their causes, and the pattern of associated symptoms.
• How are infections of upper respiratory tract different from those of lower respiratory tract?
• Why are infections of the upper respiratory tract milder as compared to those pertaining to the lower respiratory tract?
• Describe the curative methods for each of upper and lower respiratory tract infections.
• What are three specific factors of the immune system that help to clear the lower lung of infectious agents?