Immunology

3 Layers of Defense

1. Barriers

2. Innate Immune System

3. Adaptive Immune System

Immunity

The ability to resist organisms or toxins that tend to damage tissues and organs

Keratinocytes

Produce cells of the outermost layer of the epidermis

Stratum Corneum

Dead, tightly layered and cornified squamous cells (thick hardened tissue)

Mucous Membranes

Lines all of the body's cavities that come into contact with the environment

Respiratory Tract (Mucus)

Mucus traps inhaled bacteria, fungi, and other particles

GI Tract

Mucus and mucous membranes help protect epithelial cells and underlying tissues from damage, how?

Respiratory Tract (Hair)

Hair-like cilia in the epithelial lining to help keep it clean by moving microbes and particles out (coughing & sneezing)

What disrupts cilia in the respiratory tract?

smoking & alcohol -> respiratory infections

B-defensins

Make microbes more susceptible to ingestion and destructions by phagocytic cells by secreting microcidal molecules

Cystic Fibrosis

A mutant gene that causes abnormally thickened and viscous secretions that block the respiratory tract

Why is skin a good chemical barrier?

- low pH

- contains a/B defensins, cathelicidin, fatty acids

- sweat, enzymatic activity = inhibit microbial growth

IgG

most abundant antibody