What defenses do microbes who have traversed the epithelium and basement membrane face in establishing a systemic infection?
- 1. Tissue fluids containing antimicrobials (antibody, complement)
- 2. Local macrophages (subcutaneous and submucosal)
- 3. Physical barrier of local tissue structure
- -viruses can spread by invasion of cells
- -bacteria have difficulty, and often posess spreading factors (eg. streptococcal hyaluronidase)
- 4. Lymphatic system (brings microbes to immune-heavy lymph nodes)