Which of the following are correct descriptions of the first

Which of the following are correct descriptions of the first line of defense?

- Involves barriers at portals of entry

- Includes chemicals such as lysozyme and lactic acid

- Involves phagocytic cells (neutrophils and macrophages)

- Involves recognition of foreign agents by their pathogen-associated molecular patterns

- Examples include the ciliated epithelium of the respiratory passages, excretion of urine, and production of tears

Solution

All these options are the correct description of the body\'s first line of defense as soon as it encounters any foreign pathogen.

It includes physical and chemical barriers such as skin, lysozyme present in tears , lactic acid im sweat, neutrophils, macrophages, urine, friendly bacteria etc. They block the entry of these pathogens at their entrance. The body recognises them by its pathogen associated molecular patterns PAMR.