Host defence in the lung Flashcards
what is our main defence in the lung against infection?
inflammation.
how does acute inflammation occur? [3 steps]
- vasodilation leads to exudation of plasma including antibodies.
- activation og biological cascades.
- migration of blood leukocytes into the tissues.
What is the specialist macrophage in the lung?
the alveolar macrophage.
What is the difference between chronic and acute inflammation?
any of these; Causative agent, Cells involved in response, onset, duration, outcomes.
why are macrophages described as a spectrum?
they can develop into many cells and can swap their phenotype.
What are the three main functions of the alveolar macrophage?
- Microbial killing
- co-ordination of the inflammatory response [cytokine production]
- induction and clearance of apoptotic cells.
What is meant by neutrophil apoptosis?
once the neutrophils have reached their target area and done their job they need to be removed to stop accumulation this is done via apoptosis [programmed cell death].
How do neutrophils migrate to a source of infection?
they can detect concentration gradients and move along it by moving its receptors to the leading edge.
how is the phagolysosome created?
by membrane invagination by the neutrophil and pinching phagosome fusion with granules.
What 3 steps allow a neutrophil to enter a cell?
- Margination with the help of selectins.
- adhesion to the membrane with the help of integrins.
- changes in structure of endothelium and in the neutrophil.
what is the role of respiratory epithelium?
to moisten and protect the airways. To protect and prevent pathogens from reaching the deep alveolar tissue, can be done by releasing mucus.
What types of molecules are included in the mucus that help to protect the lung?
water, carbs, proteins and lipids?
what molecules are secreted by the epithelium that play a role in host defence?
antiproteases, anti-fungal peptides, Surfactant.
What type of stratified epithelia is there in; 1.bronchus, 2. bronchioles, 3. alveolar.
- columnar
- cuboidal
- squamous
what is the much-cillary escalator?
the synchronised beating movement of the cilia which creates directional waves to move mucus up the airway.