When a person sees a doctor about a respiratory illness, the doctor will want to determine if the sickness is in the upper respiratory tract or the lower respiratory tract. The starting point for the lower respiratory system is the trachea. Which structures are part of the upper respiratory system? Select three options.

Which of the following is an accurate statement about pathogens? infection and disease are caused by pathogens living in infectious agents found in the environment. pathogens, which cause infection and disease, are the most abundant organisms in the environment. most organisms in the environment are harmless, except for pathogens, which can cause disease. the environment is rich in infectious agents that transmit disease through pathogens.