Which among the following is not included in first level defense?

Defense mechanism can be classified into:

i. Non-specific

ii. Specific

The action of B lymphocytes is the type of specific defense as the specific defense is the system which identifies and destroy pathogens which enter the body. Lymphocytes are capable of destroying pathogens. B-lymphocytes produce an army of protein in blood, known as antibodies in response to pathogens.

Whereas, production of sebum, the action of hydrochloric acid in the stomach and action of lysozyme in saliva is a nonspecific first level defense mechanism.