First Line of Defense

• What are the physical and chemical barriers of the first line of defense of the innate immunity?

  Skin and mucous membrane
• Epidermis: physical barrier to the ENTRANCE of microbes.
• The SHEDDING of epidermis removes microbes.
• Mucous membrane: lines the body cavities and secretes mucous.
• Mucus TRAPS microbes and foreign substances.
• Mucus coated hairs: trap and filter microbes, dusts, pollutants.
• Cilia: propels inhaled dusts and microbes towards the throat
• What are the 4 first line of defense?

  epidermis, mucous membranes, fluids, and chemicals
• Tears: drains away irritants, also contains LYSOZYME.
• SALIVA: washes away microbes from the teeth and mouth.
• Flow of URINE retards microbial colonization of the urinary system
• Sebum: forms a protective fil on the surface of the skin and inhibit bacterial growth
• Gastric Juices: destroys bacteria and toxins