Pathology of Infectious Disease Flashcards
What is upper respiratory tract composed of?
Nasal cavity, pharynx, larynx, trachea ( zone between upper and lower)
What is the lower respiratory tract composed of?
Bronchi, lungs, diaphragm.
What is the main defense against viruses?
Respiratory tract is the main defense against viruses –> especially the nasal epithelium.
Nasal Cavity does what?
The nasal cavity warms, filters, cleans air on it’s way to lungs.
What are the cells making up nasal cavity?
Ciliated columnar cells, basal stem cells, goblet cells, neuroendocrine cells.
What respiratory epithelium is made of what?
Ciliated cuboidal mucosa +goblet cells
First line of defense: pathogens have to get through mucosa and past the cilia in order to infect the respiratory system.
Larynx
Respiratory Epithelium: pseudo-stratified columnar epithelium + goblet cells.
Non-Keratinizing Epithelium: no sero-mucous glands, no lymphoid tissue.
What is the thyroid composed of? What is the epiglottis composed of?
Thyroid Cartilage: hyaline cartilage.
Epiglottis: Elastic Cartilage
What is the histology of the trachea and bronchi?
There is cartilage, smooth muscle, and epithelium.
The epithelium has goblet cells, basal cells, and ciliated columnar cells.
What is the histology of bronchioles and terminal bronchioles
The histology is smooth muscle and simple ciliated columnar epithelium with club cells.
What is the histology of the respiratory bronchioles?
Respiratory bronchioles is smooth muscle and respiratory epithelium with club cells and cuboidal ciliated cells and squamous cells
What is the histology of alveolar sacs?
The histology is alveolar sacs: Type 1 Pneumocyte, Type 2 Pneumocyte, Alveolar Macrophage, capillary.
What are common patterns of lung disease?
Diffuse alveolar damage, granulomatous disease, diffuse interstitial mononuclear cell inflammation (viral pneumo), intra-alveolar supperative inflammation, viral inclusions
What are most URIs?
They are viral in nature.
What are the following diseases most likely caused by?
Epiglottitis and Laryngotracheitis:
Pharyngitis:
- H. Influenza Type B, and Corynebacterium diphtheriae
2. Strep Pyogenes
What is the pathogenesis of bacterial infections of the lung?
Elaborate enzymes that damage host cells. Capsules are resistant to phagocytosis and have surface M protein adhesin molecules.
What is the pathogenesis of viral infections?
They require entry into host cell for replication causing lysis and inflammation of the cells and tissue.
What is the pathophysiology of SARS Cov- 2?
- There are hemagglutinin spikes that bind to Sialic acid on the respiratory epithelial cells.
- The COVID-19 virus binds to the ACE-2 and Tmpress 2 are cell surface receptors on respiratory epithelial and endothelial cells are used by viruses to enter epithelial cells are used by viruses to enter epithelial cells of the upper airway nasal lining cells.
- The ACE-2 receptor causes a host cell: causes there to be multiple effects. Cytokine storm, ACE 2 activation which causes hyper-coagulability and micro-angiopathy. This can cause hypoxia and damage lungs.
- Direct viral infection causes rhabdomyolysis and tubular epithelial and podocyte damage causes kidney damage.
- Hypoxia and hypotension.
Neuraminidase is used for what by SARS-Covid-2 :
To exit the cell.
What cytokine storm?
All cases of cytokine storm involve elevated circulated cytokines, acute systemic, inflammatory systems, and secondary organ dysfunction.