• Describe the normal host defense mechanisms of the respiratory tract and how these influence infection

• Mucus • Cilia (muco-ciliary escalator/elevator) • Nasal secretions • Antimicrobial peptides • Alveolar macrophages

Saliva

above is a list of the host defences present in the Respiratory tract against infections ^^^

mucus - traps forgein bodies/particles from entering the cells of the body to cause harm

cilia - works to move mucus which is the barrier against pathogens and forgein bodies entering the body

Nasal secretions - allows for the exit of pathogens

Antimicrobial peptides - these are produced to aid in innate immune response

Alveolar macrophages - they are a type of WBC present in the respiratory system, they are a first line defence

Saliva - enzymatic breakdown of bacterial cell walls by lysozyme and sequestering iron by lactoferrin

• Describe the ways in which pathogens establish infections in the respiratory tract