Answer: Bacterium inhaled from air alongside oxygen can be isolated by mucous membranes and eliminated by multiple immune defenses of the respiratory system.
Explanation:
The respiratory system consists of cilia and mucous membranes which lines the inner surfaces. These surfaces are made up of goblet cells which secrets a layer of sticky mucus. When microorganisms such as bacteria is inhaled along with oxygen, the viscosity and acidity of the sticky mucus inhibits microbial attachment to the underlying cells. The beating of cilia propels the mucus with any trapped bacteria towards the epiglottis where it is swallowed. This process of elimination prevents bacteria from further invading the lower respiratory tract.
Multiple immune defenses of the respiratory system includes:
--> mucosa associated lymphoid tissue (MALT): these includes adenoids and tonsils.
--> lysozyme
--> Surfactants
--> defensin (antimicrobial peptides)
--> alveolar macrophages
The activities of the multiple immune defenses of the respiratory system helps in the isolation and elimination of inhaled bacterium.
