The immune system is the third line of defense

Question 1

First line of defense

Answer 1

●Skin
●mucous membranes
●secretions of skin and mucous membranes

Question 2

Second line of defense

Answer 2

◇ phagocytic white blood cells
◇ Antimicrobial proteins
◇ The inflammatory response

Question 3

Third line of defense( Specific defense mechanisms)

Answer 3

☆ Lymphocytes
☆ Antibodies