🌟 Cues

Upper Respiratory Tract Infections (URTI)
- Causes: Viruses (majority), Bacteria (secondary or primary)
- Differences between Viruses and Bacteria (infections, treatment)
- Key anatomy involved in infections: Nasopharynx, Oropharynx, Sinuses, Eustachian Tube
- Bacterial infections can be treated with antibiotics, viral infections are self-limiting.

🗒️ Notes

Upper Respiratory Tract Anatomy:
- Nasal cavity, pharynx, and associated structures (e.g., tonsils, sinuses) are involved in defense.
- Infections can affect areas like the sinuses (sinusitis), the middle ear (otitis media), or throat (pharyngitis).
- Children are more prone to URTI due to narrower Eustachian tubes.
- Symptoms of bacterial infections: fever, purulent discharge, and pain.

Viruses vs. Bacteria:
- Viruses: Cannot grow outside living cells, transmitted via droplets, require cell culture to grow, mostly self-limiting.
- Bacteria: Can grow independently, may require antibiotics, grow in culture media, visible under the microscope after Gram staining.
- Common bacterial infections: Streptococcus pneumoniae, Hemophilus influenzae.
- Antibiotics are required for bacterial but not viral infections.

Defense Mechanisms:
- 5 ways the respiratory system prevents infection: Nasal hair, IgA antibodies, ciliary escalator, alveolar macrophages, and normal microbiota.

Complications:
- Sinusitis: May lead to secondary bacterial infection, treated with antibiotics.
- Otitis media: Common in children, can lead to middle ear infection, treated with amoxicillin or alternatives for penicillin-allergic patients.
- Antibiotic resistance: Overuse of antibiotics can lead to resistant bacterial strains.

📝 Summary

Upper Respiratory Tract Infections (URTI) are commonly caused by viruses and are often self-limiting, but bacteria can cause more severe infections that require antibiotics. Key structures like the nasopharynx, sinuses, and Eustachian tube play important roles in defense and are also sites where infections commonly occur. Proper diagnosis and management, including the use of antibiotics when necessary, are essential for treating bacterial infections, while supportive care is sufficient for most viral infections.